This invention relates to rotary blade arrays or turbines, for the transfer of energy to and/or from relative fluid flow movement, whether liquid or gas. Either or both wind or water turbines are embraced, in driven, say generator, or pump or driving, say, impeller or stirrer, modes. In a fluid-driven generator mode, the interaction between fluid and blade creates a reaction force tending to engender blade rotation. This in turn can be coupled to a generator to capture and convert flow energy into electrical energy. In a driving mode a power source drives an impeller to displace a fluid . The term blade embraces any profile, contour or infill paddle, panel, sheet, slab, band or strip.

Convoluted or twisted , say helical or spiral wound or fluted forms are also embraced.

Some aspects of the invention are concerned with complex or multiple independent or interdependent rotational modes or interactions directly between blades or indirectly with a superimposed flow, such as with multiple (intersecting and/or angularly offset) rotational axes. Blades can be collective in groups or clusters. Two, or groups of two, in particular mutually orthogonal, rotational axes, are a prime category of interest in the present invention. Opposed (say, diametrically at opposite ends on a common diameter) blade disposition with similar if not identical blades helps with static and dynamic balance. That said, for the purposes of investigation a single blade with an intermediate pivot or a radial blade with an end pivot could be employed.

Blade disposition, orientation and interaction with a flow, along with blade shared influence or mutual inter couple effects are explored ; as are behaviour in different fluid media, such as a liquid (water), and a gas (air - i.e. wind). Blades could be set in an open environment or within an elongate directional duct confines to concentrate, focus and direct flow superimposition upon blades.

Prior Art

Wind turbines are commonly categorised by blade axis disposition or orientation, as either Horizontal Axis (HAWT) or Vertical Axis (VAWT), reflecting the disposition or orientation (in a vertical plane) of the blade assembly rotational axis. HAWT is more common, albeit may require steering orientation into the prevailing wind, for which an upright guidance vane is sometimes employed ; whereas a VAWT can address wind from any direction. Variable pitch blades are also used.

Blade mounting mobility or freedom of movement has a bearing upon how the blades experience and react to an impacting fluid flow. If the blade reaction is a movement, that in itself impacts upon a subsequent blade 'flow experience' and in turn a blade reaction to that. One freedom of movement is a complete rotational freedom about a vertical axis, in the manner of a VAWT. Another freedom of movement is complete rotational freedom about a horizontal axis in the manner of a HAWT. But these freedoms are available and exercised simultaneously, so one is susceptible to influence by the other.

Elaborate horizontal axis turbines have been devised, such as continuous helical or 'trussed' blade variants of the so-called Darreus type, investigated by Oxford university and the subject of a Transverse Horizontal Axis Water Turbine (THAWT) study paper, accessible per web link http://www- civil.eng.ox.ac.uk/research/tidal/EWTEC2009_THAWT_paper.pdf.

Vertical or upright axis upstanding wind generator turbines or VAWT's have been devised with diverse blade configurations, including diametrically opposed sets and continuous curvilinear forms such as helices, with the broad agenda of optimising blade presentation orientation in relation to the impacting ambient air flow. However, these are commonly of fixed format assembly, blade profile, pitch and/or orientation. US7, 726,934 uses upright flexible paddle blades of variable cant or lean set upon swivel joints at the outboard ends of radial carrier arms. Continuous rotary archimedes screws or auger turbines have also been used for water turbines, such as for low speed water transfer or lift, usable in reverse as a generator. However, these do not necessarily optimise the interaction of blade and fluid. Combination wind and water turbine combinations have been proposed, such as per 2009 0107567, using wind power to pump water to a storage tank whose drainage is used to generate electricity. This rather than, say, using one or other or potentially both water currents and overlying air currents, such as in a tidal estuary, to turn respective blade sets according to ambient conditions.

Centrifugal weight control of wind or water turbine rpm is also known to regulate or govern speed in relation to surges in wind or water flow; an objective being constant operating speed or rpm. This to suppress, inhibit or vitiate energy capture with increasing flow beyond a set threshold.

Statement(s) of Invention

The invention variously embraces:

A rotary blade assembly

mounted with multiple freedoms of rotational motion

for co-operative blade interaction

with an impacting fluid flow.

A rotary blade assembly or array

with multiple freedoms of rotational motion,

or freedoms to rotate about one or more multiple axes,

for co-operative blade interaction

with an impacting or immersed fluid flow.

A wind or water turbine incorporating

such a blade assembly

mounted upon adapted for orientation in a flow

and coupled to an electrical generator.

A rotary blade assembly or array

in which a blade moves through

or is impacted by a fluid flow

but its pitch is changed with its motion

to optimise blade movement along with or by the flow

and minimise blade action counter to the flow.

A rotary blade assembly or array

in which a blade is rotatable about one or more axes

for motion through or impact by a fluid flow

and blade pitch is changed with its motion

to optimise blade movement with or by the flow

and minimise blade action counter to the flow.

A multiple rotary axis blade assembly or array

configured for blade pitch variation

for optimised impact by and minimal counter to a fluid flow.

A blade assembly or array

in which one blade sets the pitch of another

about a common rotational axis

in relation to an impacting flowing flow.

A turbine with one or more blades

in an mutually co-operative assembly or array

set about a intermediate spindle

with a 3D profile presenting a flat plane or an aerofoil form

whereby blade motion in a plane perpendicular to the spindle

presents optimal surface area to fluid flow

to promote spindle rotation.

The term rotary embraces angular, arcuate or oscillatory motion, that is without necessarily a complete 360 degree transition. Prime fluids for blade interaction are air and water for a blade assembly operative in a natural environment using freely available wind and water motion energy. Blades can interact directly and individually with a flow and/or indirectly with one another through mutual flow intercouple. Thus the flow interaction of one blade can impact upon that of another, as a blade affects the local flow and that in turn impacts upon another blade. This can be a significant consideration for closely disposed blades, such as mutually internested blades in a common rotational plane or in tiered rotational planes in a stack.

Blade motion freedoms can be through a plurality of discrete rotational axes, including an independent blade axis through, or juxtaposed alongside, a blade body and a driving or driven axis intersecting or at an angular disposition to the blade axis. An example would be mutually orthogonal blade rotational axes. Blades can be set in planes at right angles to one another, but mounted upon a common carrier axle. Blades can be mounted upon a common carrier axle, itself mounted for rotation upon a driving input or driven output shaft. Blades can be set upon a common blade axle, in co-operative groupings or pairs, at opposite diametral ends about an intervening mounting shaft.

A horizontal blade carrier axis can carry diametrically opposed blades about a central vertical or upright mounting shaft. Multiple blades could be grouped in complementary pairs upon a common axle. Multiple stacked layers or tiers of blades could be grouped in pairs upon respective carrier arms or axles. Blades can be set in stacks or tiers in common planes. Blades can be disposed upon stacked carrier axles of different span and/or relative angular offset about a common mounting shaft.

Blades upon a common carrier axle can be orientated or angularly offset for relatively phased or 'anti-phase' blade action, such that in part of a rotational cycle or half-cycle, one blade is active, working or contributory, in driven or driving mode, for optimum flow interaction and flow energy extraction and conversion, whilst an opposed blade is inactive or passive, orientated for minimal flow disturbance and attendant drag. An inactive blade orientation can be set for minimal side edge intrusion into a fluid flow and an active blade orientation set to intersect flow lines or flow strata across the flow.

Individual blade orientation upon or about a common blade carrier axle can reflect an interaction with a flow in which it is immersed and also the orientation of another blade on that shaft. Blades can be mutually interactive as between themselves and with the flow, for rotation about a common blade axis and for rotation of that axis about an intersecting mounting shaft.

The rotational speeds about different rotational axes can be independent, relatively phased, synchronised or otherwise co-ordinated. Thus blades set at opposite ends of a common diametral or aligned radial shaft or axle could rotate about an orthogonal 'driving or driven' axis disposed intermediate between those ends, say at mid-span, at a rate determined by the prevailing relative flow; but also rotate about the common axle, again together or independently, at a consequential rate reflecting the rotation about the driven axis. The dual rotational modes are thus directly or indirectly intercoupled by a shared flow experience. Rotational variations could allow one rotation to slow, even to a halt temporarily, or to speed up, whilst another rotation continues independently at its own speed. That said, the respective rotations can serve as a mutual trigger, so slowing of one rotation can be counteracted, or revitalised by an ongoing other rotation.

An alternative can be to set blade orientation about the common diameter by some (super) imposed drive. Again the objective of blade setting will be to optimise energy extraction from the flow by a blade driven by and moving with the flow, whilst minimising interference with the flow by a blade moving against, counter or into the flow.

The relative proportions of blade areas about, or to either side of, the axes will affect rotational leverage turning moment or torque about those axes. Thus, say, a large blade area (offset) to each side of an intervening, say vertical or upright, output shaft will tend to bolster rotation about that shaft, given a sufficiently robust fluid flow impacting upon the blades. Blade offset or asymmetry can lead to an uneven , cyclical, oscillatory or pulsed motion, but any A blade movement , however variable, erratic or short-lived, by and so moving with the flow on one side can be harnessed to contribute to, in fact may be a prime source of useful output.

A corresponding or companion blade moving against the flow on the opposite side of the shaft will act to counter that rotation with a tendency to rotate in the opposite direction, so does not make a useful contribution, rather the opposite in imposing blade drag, which if transferred to an opposed working blade undermines the contribution of that blade. That applies if both blades are similarly orientated and sized. The present invention envisages a relative angular offset in blade orientation, such as about a common diametral rotational axis, between the blades on opposite sides of the shaft. This for

complementary rather than mutually counter blade action.

Such considerations also apply to the relative proportions of blade areas about a, say horizontal, common blade carrier axle through or adjacent the blade bodies, say coincident with the blade longitudinal axis. If the blade areas on opposite sides of the carrier axle differ, their reactions to a common impacting fluid flow will not be matched or counterbalanced. A larger blade area will be more influenced by an impacting fluid flow and so dictate an initial rotational tendency, in that side will move more readily or pronounced with the flow. That will continue until that blade areas is no longer squarely or partially obliquely across the flow, whereupon the lesser blade area on the opposite side of the carrier axle exerts a greater influence upon rotational direction and stands to make a greater temporary output contribution, albeit not necessarily in the same direction. Blade rotation can thus be hesitant or uncertain and reverse, oscillate, flutter or dither. A sufficiently strong flow may over-ride any such blade flutter, in favour of continuous unidirectional rotation through blade momentum.

The blade and flow interactions about the two rotational axes will also have an intercouple effect or interaction. There may be a greater predisposition to rotate about one axis rather than the other. Once that rotation starts, it may have a dominant or overriding effect over the other rotational mode. If on the other hand the respective effects about the different axes are more balanced, this in turn may engender a hesitant, fluctuating or oscillatory blade motion tendency. This can be referred to as blade 'dither', rather than continuous blade rotation as might be desired for more ready motion energy capture and extraction.

A particular consideration of the present invention is blade disposition and motion.

Another is to obviate counterproductive blade and impacting or immersed flow effects. Whilst in a conventional HAWT a common blade rotational axis may be pivot mounted, offset from but close to the common blade centre in a moment arm about a vertical pylon axis, to swing in an arc for wind alignment, that axis does not rotate fully or continuously. In contrast, some aspects of this invention allow continuous rotation, about a vertical axis, of a horizontal blade rotational axis, such as a common or shared blade carrier axle. Again, in a conventional HAWT blades are mounted radially from an inner end in a cluster at one end only, whereas some implementations of the present invention blades are mounted at opposite ends of a horizontal blade rotational axis, such as upon a blade carrier axle. The blades themselves are mounted across the blade carrier axle, so the blade rotational axis intersects the blade body. A vertical (shaft) rotational axis intersects the blade axle at mid-span, so the blades at opposite ends exert a lever arm moment upon the vertical shaft.

In some aspects of the present invention a combination VAWT and HAWT modes and/or elements can be utilised , in which orientation of a blade array, or at least active or contributory blades, in a prevailing fluid stream, in particularly air flow, is influenced or determined by blade disposition. An element of blade self-alignment or optimisation with the flow can be achieved. A horizontal blade at one outboard axle end is comfortable or stable to remain in a flow without disturbance. An upright or vertical blade can also be aligned with a flow and so stable or comfortable to remain as such ; but if disturbed across the flow is unstable and so does not remain in that condition, but rather tends to rotate about a horizontal axle and to take that horizontal axle around with it about a vertical axis, until it itself is re-aligned with the flow. As a horizontal axle itself rotates about a vertical axis, so that axle alignment action may continually change.

In a rotary blade array or turbine, blade movement can be a freedom of rotation about an individual and/or collective rotational axis. Allowing independent blade movement, or for one blade directly or indirectly to influence or interact with another, can be used to advantage. This can apply for some or all blades. Blade mobility and interaction can be in disposition and/or orientation; rather than a fixed (relative or absolute in space) blade disposition or orientation. Certain blades can be associated for mutual interaction. Blades can be grouped in pairs for this purpose. Blade interaction can be effected by direct mechanical link or indirect drive coupling. Useful or productive blades or blade action can be harnessed , whereas less useful or even counter-productive blades or blade action can be rendered less counter-productive or more ineffective.

With a fixed blade disposition or orientation in a rotary blade array, Individual blade and flow interaction can vary with rotation of the blade array. Thus, not all blades are necessarily similarly influenced by, or best placed to interact with, a shared impacting fluid flow. Some blades have a co-operative flow interaction others less so. It would be desirable to reduce or obviate adverse or counter-productive blade-flow interactions. It would be preferable temporarily to feather or reduce the pitch of that individual blade in relation to an impacting flow. This whilst preserving productive beneficial blade and flow interactions. As blade-flow interactions vary in a rotational cycle, so a variable blade pitch adjustment according to rotational phase would be desirable, if it could be implemented economically. Intercouple, say by pairing, of blades which reach their optimum pitch with other blades at their least beneficial pitch; as 'phase-related' blades. A blade could automatically set a phase-related companion blade. Blade pitch can also be used to effectively 'gear' up or down the blade drive by the flow, by presenting more or less resistance. Blade pitch variation is known in certain propeller and rotary wing configurations, but they involve blade rotation about a single axis, that is in one rotational mode, rather than multiple modes as with the present invention.

In a particular blade configuration, opposed blades, that is blades mounted at

(diametrically) opposite sides of a shared (output or driven) shaft, itself mounted upon an orthogonal (output or driven) shaft, could share a common blade rotational axis, if not a common carrier axle. This would positively (mechanically) interconnect the blades and so allow the behaviour of one blade (under its local flow) to affect, if not dictate, the behaviour of a remote opposed blade (under its local flow). A 'useful' blade and flow interaction is thus not undermined by the disposition and flow interaction of a counterpart opposite blade in a less favourable disposition and flow interaction.

Blade movement itself creates a local flow disturbance, which if severe could also disturb the flow around the opposite blade, in addition to the disturbance caused by that blade itself. That said in certain configurations flow disturbance caused by one blade could be arranged to have a beneficial or useful contributory effect upon another blade.

Blades could be drivingly intercoupled, if not directly by such a common axle, then indirectly by, say, a magnetic clutch with clutch drive coupling faces close to, but on opposite sides of, an output shaft. This would allow, say, a multiple radial spider arm array of blade axles with intersecting blade axes about a common centre at the output shaft, which might otherwise be impeded by conflicting carrier axles. Alternatively, a blade stack could include closely (vertically) stacked blade carrier axles running through a common output shaft or respective bushes with a common axis.

If blades are allowed to rotate freely individually, i.e. are wholly uncoupled one from another, aside from any shared flow influences, their behaviour reflects the blade mounting upon its own axis. Thus, for a symmetrical blade mounting about its axis, with equal moment on opposite sides of the axis, it could simply 'flap', that is self-settle in pitch away from impact with the flow to lie neutrally in the plane of the flow, or continually 'hunt' or oscillate one way then the other for equilibrium.

The nature of blade motion, both about an individual blade axis generally in the plane of the blade,

and about another (say driven, driving or output axis for blades individually and collectively) can vary. This applies to direction, frequency, amplitude, whether in analogue or digital (e.g. pulse) mode. Such motion may or may not be entirely predictable. In some respects, this need not necessarily matter, as any form of coherent or random motion, 'freely' extracted from ambient natural wind or water flows, might be harnessed productively, whether intermittent, sporadic, oscillatory or fully rotational. That said, a continuous unidirectional motion is advantageous for an even, regular output.

Some blades may undergo random or chaotic fluctuations in position and/or orientation, others may adopt a more stable consistent condition. Again, blade motion or freedom of motion may be independent, or contingent upon that of other blades in the vicinity, whether or not positively, say mechanically, intercoupled. Another consideration of blade motion is if the intention is to reap energy or merely for visual effect, such as in a toy or executive game or mobile, where an entrancing blade motion suffices. More liberal blade mountings and rotational modes could be contemplated where only a visual outcome, such as an intriguing unpredictable motion regime is sought.

Although convenient for ease and consistency of motion energy extraction, continuous coherent unidirectional rotational blade motion is not essential for energy extraction from a superimposed flow. Thus, even uncertain or chaotic blade movement, flap, flutter or dither could be harnessed , such as by compensatory or corrective or restorative electronics in a blade driven generator output. Any and all blade movement is potentially contributory or productive if appropriately captured and transferred, such as to interim electrical power storage battery or accumulator.

One rotational axis could be an elongate blade axis. Another rotational axis could be transverse to the blade axis. A rotational axis could intersect or be offset from an elongate blade axis. A rotary blade assembly could feature a single blade, with an intermediate or offset rotational axis, An eccentric blade mounting would be an example configuration. A useful characteristic is adjustment of blade pitch, that is angular orientation about one axis, to maximise the effect of blade and superimposed flow interaction when a blade is driven by, and moves along one path in harmony with the flow and to minimise the otherwise counter or contrary drag effect when a blade is moving in a return path against the flow. Self or automatic blade adjustment is convenient to optimise blade orientation with its movement in a flow; even if the flow changes.

An array of mutually internested blades in co-operative relative disposition could be located in open air or in a duct. An example would be a stack of diametral blades set on a common driven shaft or output axis, with opposed blade pairs rotatably mounted about each diameter, and successive blade tiers in the stack relatively angularly offset about the common driven shaft. The blades on a driven shaft are inset within the rotational diameter of an adjacent shaft, either synchronised at the same height or staggered in height to orbit between the blade paths or planes of blade movement of the other shaft. That is the blade diameters overlap, either at same height with mutually phased rotation or at different heights. This for a more compact assembly of driven shafts in an array, which is helpful for location within a common directed flow duct. Blade close proximity or juxtaposition also allows for co-operative intervening air flow, with beneficial mutual blade influence and behaviour. Blades could thus have a collective turbine effect with modest individual contributions collectively have a large and consistently even contribution to motion energy extraction.

A particular rotary blade assembly, has a plurality of non-aligned and/or non-coincident rotational axes, including an independent blade axis and a driving or driven axis. Thus, say, an opposed blade array could be rotatable about a drive or driven axis between spaced blades, set at a relative angular disposition and rotatable about respective blade axes, at a relative angular disposition to the drive or driven axis. Opposed blades may share a common blade axis. Drive(n) axis and common blade axis can be mutually orthogonal and disposed to intersect. Blades can also be set mutually orthogonal.

Blades can be symmetrical or different in planform and/or section. Blade disposition can be symmetrical or asymmetrical with respect to the drive(n) axis. Blade disposition can be symmetrical or asymmetrical with respect to a common blade axis. A flat or curved blade surface profile, smooth, rough / irregular, rippled / stippled surface contour can be adopted . Blade tip upstands can be used to reduce vortices and drag. This presupposes a coherent flow direction, which may not always be determinable with dual rotational modes. A blade array may comprise multiple opposed blade sets. Thus, say, opposed blade sets can be stacked or tiered upon a common drive(n) shaft.

In one construction, similar, even identical, twin blades or paddles are fitted at opposite ends of a shared blade carrier axle and set at 90 degrees relative angular offset to one another about that blade axis. The blade axis passes through the mid-line or centre of symmetry of each blade. The blade carrier axle itself is carried upon and free to rotate about a drive(n) shaft, as an output or input shaft, at right angles to the blade axle.

In principle, blade rotation about a blade axle could be independent of rotation of that blade axle about a drive(n) or output shaft. Thus the blade axle could rotate about the drive(n) shaft while the blades remained stationary about the blade axle; or vice-versa. In practice, when subject to an impacting fluid stream, both rotational modes tend to arise and can affect one another, or mutually intercouple. Either or both rotational modes might freeze or 'stall' unpredictably, at certain dispositions and/or orientations to an impacting flow. This susceptibility might be countered with supplementary blade sets at different orientations, so they are not all affected simultaneously in the same way. Thus the momentum of an 'active' or 'enabled' blade set might be used to carry an otherwise stalled or stationary blade set through a 'dead', or inactive zone and allow that blade set to re-establish itself in rotation or re-energise.

Generally, a blade set across a flow will tend to rotate if different areas are presented on opposite sides of a blade rotational axis, so the flow impact has asymmetric or un(counter)-balanced effect. Once blade rotation starts, the unbalance remains and is even exacerbated, promoting rotation. Rotation might be continuous in one direction once started, or slow down, stop and reverse after a certain angular displacement, leading to oscillatory motion. A blade set 'squarely' orthogonal to a flow and symmetrical about a blade axis might receive equal and opposite or counterbalanced turning effect and so remain stationery or stall. A blade completely aligned with a flow tends to stay static. A slight disturbance can upset blade 'neutrality' and engender either return to station or a continued disturbance leading to rotation. Such instability or volatility can be used to advantage to promote continuous rotation or oscillation either or both of which can serve for generation or disturbance.

In one example operational cycle for opposed blades on a common (say, horizontal) carrier axle, itself carried upon an orthogonal (say, vertical or upright) drive(n) or output shaft, one blade interacts with an impacting fluid flow and aligns itself with the axis of a drive(n) shaft and rotates the shaft by applying an offset radial lever arm or moment action. Meanwhile, the opposite blade turns against the fluid flow, but presenting the minimal cross-section of its thickness, so does not impede rotation. After part (say, one half) of a revolution of the drive(n) shaft, the blade carrier axle rotates a quarter of a revolution about its own axis, as the two paddles reverse their roles. So, in this example, one complete revolution of the blades about the blade carrier axle results in two revolutions of the drive(n) shaft. This may not happen universally, so part rotations followed with reversals, referred to as flapping or dithering may arise. A rotational travel limit or abutment stop may be fitted to the blade mounting to constrain blade flap or dither range.

Diverse blade shapes could be employed in planform (round , square, oblong, triangular or oval shaped), but will be large compared with their thickness. Blade cross-sectional profile might show some thickness at it's centre for strength, but thinning out or waisting at front and rear edges. These edges are preferably straight, (at least for ease of construction if not aerodynamic effect). Aerofoil sections might be used.

The blade outboard disposition or offset from the drive(n) shaft contributes a turning moment or torque about the drive(n) shaft. The offset length or span of a blade axle from the drive(n) shaft may be different according to its duties. This length will also effect the speed of rotation of the drive(n) shaft and the torque characteristic for a given rotation and so overall energy transfer between the blades and an impacting fluid flow.

Various designs of blade carrier axle support where it passes through the drive(n) shaft can be employed. Thus, a simple bush or sleeve plain bearing may suffice for some (lighter loaded or less onerous) duties, but a more elaborate ball or roller bearing arrangement for higher loading. Coupling of axle and shaft must be robust, as it is through this that energy is transferred .

More than one opposed blade pair or set could be attached to a common shared drive(n) shaft. Thus blade pairs could be stacked or tiered, one blade carrier axle over another, upon a common drive(n) shaft. The relative spatial positioning, i.e. distance apart on the shaft and relative rotational angular alignment offset of the blades and axles will be important. Thus, with say two blade carrier axles on a common drive(n) shaft, the relative shaft angle might be ninety degrees. The drive(n) shaft might be mounted either vertically or horizontally, depending upon the application. One prime application is the capture of energy from wind using the assembly with a vertically mounted shaft in the manner of a VAWT. The (output) shaft might need bearings at both ends and these will need to be located in a support structure. Alternately, a single bearing assembly at the lower end might be possible. An advantage of the blade set in the vertical position is that supports can be fixed in position because the unit does not require a special orientation for the blade set to catch the (prevailing) wind.

A drive(n) or output shaft could be mounted horizontally, but this could require bearings and housing at each end of the shaft. This would benefit from a specific optimised orientation to the wind to maximise the interaction of the blade set. Circumstances might occur in which the flow of gaseous fluid was not wind, but confined gas flow such as in a duct. Another possible situation arises with a fluid as a liquid such as water flowing in a stream, channel or duct. A preferred arrangement might involve a contained flow in a channel or weir and the preferred design would be horizontal rather than vertical arrangement. Optimum paddle designs might differ between air and water applications. Multiple, in particular two, blade rotational modes, about respective different, say, orthogonal axes can usefully be employed. For dual rotational modes, one rotational axis, for blade pitch change, can lie about a blade axis in the plane of a blade and

longitudinally of an elongate blade profile. The other axis, representing a driving or driven axis for the blades individually and collectively, can be orthogonal to the blade longitudinal axis. The rate of rotation about the longitudinal axis can differ from, say as a multiple of, that about the orthogonal axis.

Use of opposed blades in pairs on a common diameter, but on opposite sides of a driven or driving axis, means the blades experience different flow interactions for each angular position throughout a rotational cycle. The respective experiences may be opposite, with the risk of one blade undermining, countering or opposing the (say, beneficial driving or driven) effect of an opposite blade.

A (temporarily) inactive or non-working blade, or rather blade cycle or half-cycle, can feature a blade orientated or 'feathered', alignment with minimal side edge intrusion into a fluid flow. Whereas an active or "working' blade can be set to 'intersect' flow lines or flow strata, more across the flow. A blade motion cycle can reflect a composite rotational mode, say, about its own axis, and also about a relatively offset or displaced axis. These axes can be mutually orthogonal. A prime example would be blades set in planes at right angles to one another, but mounted upon a common carrier axle. That axle could itself be mounted for rotation upon a driving input or driven output shaft.

Individual blade orientation upon or about the common blade carrier axle reflects an interaction with a flow in which it is immersed and also the orientation of another blade on that shaft. That is the blades are mutually interactive, or effectively intercoupled, as between themselves and with the flow. The blade and flow interaction is also reflected in rotation of the opposed blade assembly upon or about the driving or driven shaft, respectively in impeller or generator modes.

A 180 degree arc of blade sweep features a portion 'across' a flow bounded, by portions more aligned with the flow. A successive 180 degree arc of blade sweep takes the blade again across the flow, but with opposite blade faces presented to the flow. A counterpart blade is set at 90 degrees out of phase with that, so passes across the flow when the other blade is more aligned with the flow. As the blade assembly rotates, so blades repeatedly and cyclically 'flip-over' from one side to another, at a rate which is a multiple of the overall blade array assembly rotational rate. In that complex mode periodic blade accelerations may arise, reflected in a 'pulsed' output reaction.

The rotary blade array admits of a blade span from an outer circumferential perimeter inboard to close the axis of rotation and/or the intersection of blade axles and driving or driven shaft. Thus blade width can follow that of a carrier axle, i.e. the axle can run through the blade, or a blade can be fitted to an outboard end of the axle. Subject to dynamic balance considerations, blade span transversely of the axle, can be equally distributed about that axle, or asymmetric to one side or other. Blades on a common axle or axis of rotation can lie to opposite sides of that axle.

Blade motion output capture and motion energy extraction is conveniently about a primary driven axis, such as a vertical shaft carrying radial or diametral blade arrays, say by generators coupled to the shaft end ; but blade motion capture about the radial or diametral blade carrier axles could also be contemplated, such as by small local generators at the blade roots. As the respective blade motions may well differ in nature and timing or phase, electrical means may be used to harmonise and/or unite or combine the outputs from the different blade rotational modes. Corresponding blades, or rather blades undergoing similar motion, if that can be predicted with certainty, can be mutually intercoupled for a common or joint output coupling. To cope with diversity in blade motion, each blade, or blades which cannot be conjoined, could have its own small local generator. Similarly, if conjoined blades fall out of synchronicity, sensed and recognised electrically or electronically, they can be uncoupled electrically and their individual outputs gathered for electrical unification elsewhere.

A blade body can flex under load in motion and its mounting can accommodate that in diverse ways. One example would be a solid swivel or resilient bearing at an (outboard) end of a blade carrier shaft. Similarly, with the (end) mounting of a driven or output shaft. Blades set in a duct can be carried on shafts with end mounting bearings in the duct walls. Output shafts set transversely or diagonally across a duct are conveniently mounted in opposite end bearings in the duct wall, at or from which electrical generator coupling could be made. A blade array could share a common gimbal bearing mounting, such as by output shafts, with respective blade carrier axles, radiating outward from a mounting sphere.

Embodiments

There follows a description of some particular embodiments of wind turbines or blade arrays of the invention, also of some relevance to water turbines, with certain VAWT features or operational modes, by way of example only, with reference to the

accompanying diagrammatic and schematic drawings, reflecting a progressive elaboration of a core modular blade and mounting format, and in which:

Figure 1 A shows a 3-D perspective view of basic dual-opposed blade array 11 , with pairs of symmetrical elongate blades 15 set upon a common transverse or horizontal carrier axle 12 through a common longitudinal axis of the blade bodies and to opposite sides of an upright or vertical central driven output shaft 14; mechanical output can be transferred to a generator (not shown) for electrical power production; the arrangement could be operated in reverse, as an impeller, stirrer or agitator for a fluid medium by substituting a motor for the generator or operating the generator as a motor by applying electrical power input;

blade format admits of considerable variation, from flat panels or slats to curved aerofoil profiles;

the opposed blades 15 are equidistant from the intervening central shaft 14 and are set at a fixed relative angular or rotational offset, in this instance 90 degrees for an orthogonal blade disposition, about their longitudinal axis of symmetry; other relative angular offsets can be employed, with consequences for relative rotational phase, blade balance, continuity and evenness or rotation; a tilting or swinging blade carrier axle 12 (not shown) might be feasible, to allow a blade pair to ride out flow fluctuations in a counterbalanced self-settling manner, albeit with a tilt range limiter;

overall, this complementary paired blade array 11 can be regarded as a basic or elemental module for further extrapolation; additional blade pairs or modules 11 can be deployed, as reflected in subsequent drawing figures; a core attribute is a multiple rotational mode, in particular (independent) rotation about two different axes; the term independent signifies the absence of mechanical coupling, but the blades are set in a fluid medium flow or stream the fluid body serves to influence both blades and their freedom of rotation; the term rotation is used herein for convenience to embrace part, complete, unidirectional, reversible, continuous, pulsating, oscillatory, intermittent angular movement about an axis; any of these can be harnessed and converted by a generator; in an impacting or immersed flow 20, say generally from one side, the blades 15 are susceptible to a motion reaction of two kinds or modes, about two independent rotational axes; that is one kind or mode of rotation about the carrier axle 12; and another kind or mode of rotation of that axle itself along with its outboard blades about the mounting shaft 14; with alternative or bi-directional rotary directions depicted by arcuate arrows;

these orthogonal rotations are generally free and independent until flow interaction, whereupon the density and viscosity of the fluid medium presents a resistance to rotational disturbance; the respective rates of rotation can differ; that is a complete rotation about the blade carrier axle 12 need not be coincident with, nor a precise multiple of a complete rotation about the shaft 14; in practice, absent some 'harmony' in such rotational modes, the angular orientation and radial disposition of blades 15 can impede motion; conversely, when synchronised, blades can turn to offer minimal resistance or drag when moving toward the flow and present maximum surface area when laid across and moving with the flow; the otherwise independent rotations can be contrived to intercouple co-operatively with one another through the common flow intermediary;

with blades at an orthogonal angular offset about their common carrier axle 12, there is an asymmetry in blade orientation, so one blade 15 always tends to be across the flow with a tendency to rotate about shaft 14; if the blades 15 are symmetrical about a common longitudinal axis of the carrier axle 12, the blade portions on opposite sides are matched, so the blades are neutral to rotation and might rotate in either direction once disturbed; if the blades 15 are asymmetric then one side has a greater influence over the other, so the blade may have a predisposition to rotate in one direction over another and to dictate rotation of another blade;

from an arbitrary start position, an upstanding right-hand blade B2 is subjected to maximum impact by an orthogonal (air or wind) flow to one side of the output shaft 14, whereas an opposite left-hand blade B1 is aligned with the flow, presenting minimal resistance, so is subjected to a lesser if not negligible force compared with the right- hand blade B2; the blade B1 -B2 relative forces at a point in time are thus unbalanced about interposed output shaft 14 and the blade array B1 -B2 will experience a net turning moment, in an anticlockwise direction (as viewed from above);

absent blade rotation about the carrier axle 12, this motion would not continue indefinitely, since after 90 degrees of rotation about the output shaft 14 the blade B2 would lie aligned with the impacting flow, and the blade B1 would continue to be so aligned, so still have made no contribution to output; but blade B2 also tends to rotate about the blade axle 12, if not initially given the blade extends equi-distant about or above and below the axle 12, then progressively in more disturbed relative flow 20; blade B2 might rotate in either direction about the blade axle 12; in this example the blade axle 12 rotation is depicted as clockwise as viewed from its outboard end; the simultaneous rotation of blade B2 about carrier axle 12 and output shaft 14 means that after 90 degrees of rotation about axle 12 blade B2 will lie aligned with the flow, but in a horizontal plane, and rotated about output shaft 14, also by 90 degrees in certain modes; at the same time, blade B1 will have been rotated 90 degrees about the carrier axle 12 into an upright or vertical position; as its plane becomes aligned with the flow and for the next 90 degrees of rotation about the output shaft 14 presents a driving interaction with the flow 20; for the 90 degrees to 180 degrees sector the blade B1 is more 'feathered' into alignment with the flow;

blades B1 and B2 make a continuously changing contribution to output; one blade 15 in a less active or 'contributory' mode is driven by the other in a more active or 'contributory' mode; for ease of analysis, and for mutually balanced influence, blades 15 are assumed to be symmetrical in form and disposition, otherwise one blade has a different and disproportionate influence over the other; one blade may thus become dominant or over- riding, for beneficial or counter-productive purposes; the rate of blade rotation about either axis may vary, so output may be uneven; a simplified rectangular slim plate blade form is depicted for ease of illustration; rather than a flat place a symmetrical aerofoil section can be adopted ;

Figures 1 B through 1 E show plan views of the blades of Figure 1 A, at a subsequent successive stages in rotational cycles about the blade shade horizontal carrier axle 12 and the orthogonal upright output shaft 14; the relative amounts and rates of rotation about the respective axes, 12, 14 reflect blade 15 and flow 20 interaction, so the positions are merely indicative of one example at a moment in time of possible variations;

Figure 1 F shows a variant of Figure 1 A with opposed blade pairs B1 -B2 at a different acute-obtuse relative angular or rotational offset about a common carrier axle 12; a continuously variable blade angular orientation could be contemplated;

the Figure 1 A arrangement can serve as a core module for extrapolation into multiple stacked or tiered blade arrays, such as depicted in Figures 3A - 5B;

overall, the blade array 11 has HAWT features in that blade 15 mounting is upon a horizontal axle 12, along with VAWT features in that the blade axle 12 is carried upon a vertical output shaft 14; output shaft 14 and be directly or remotely coupled to a generator (not shown) to produce electrical power from the rate of mechanical work input; that is wind energy is converted into electrical energy; the generator can be wired to electronic circuitry capable of converting even oscillatory motion into a pulse stream; electrically, the generator coil windings and control circuits and allow reversed operational mode, as a motor driving blades 15 as impellers for fluid disturbance and mixing;

Figure 2A shows a variant of Figure 1 , with multiple juxtaposed identical blade 15 sets, again in opposed pairs for overall symmetry; in principle, the more blades 15, the greater the potential energy extraction and power generation from the wind; a smoother blade or output shaft 14 motion might also be engendered by multiple phased blade inputs; that said, asymmetrical blade 15 groupings and dispositions could be adopted for special purposes; blades 15 can be demountable; their sub-division and fragmentation or segmentation is a convenient way of adjusting effective net blade area; in this case blades 15 on the same side are orientated in a common plane and one orthogonal to a plane containing blades 15 on the opposite side of the output shaft 14;

Figure 2B shows a variant of Figure 2A with blades 15 at each side of shaft 14 set at a different, in this case approaching orthogonal, relative angular offset about a common blade axle 12, but each with a companion opposed blade 15 at a different co-operative offset on the opposite side of the output shaft 14;

the opposed groupings of Figure 1 A can be applied to blade 15 sets at different radial outboard positions; either fixed, adjustable or continuously variable relative angular blade 15 offset could be admitted; the intention is to obviate a stagnation or stalled blade 15 condition; that is even if some blades 15 or opposed blade 15 pairs are temporarily making minimal or no contribution, other blade 15 pairs can take over and give the array some impetus and ongoing momentum; there should be no counterproductive or 'antagonistic' blades 15, as these should be feathered and rendered ineffective or non- contributory beforehand;

Figure 3A shows a vertical or upright stacked blade 15 array of multiple overlaid tiers or layers 25, in this case a twin tier or layer stack 25 variant of the twin opposed array of Figure 1 A, upon a common output shaft 14; each layer or tier 25 could replicate the other in blade 15 format and disposition; in this case the blades 15 on each side of shaft 14 lie in a common plane, generally orthogonal to a plane containing the blades 15 at the opposite side of the output shaft 14; there remains scope for variation between tiers; the respective blade carrier axles 12 could be set aligned in a fixed common plane, or at fixed relative angular offset about the common vertical output shaft 14; the tiers 25 would have sufficient vertical separation for blade 15 rotation about their respective carrier axles 12 without mutual interference; phasing of blade 15 rotation might be controlled to allow a closer spacing, by reliance upon blade 15 internest; blade axle 12 planes could themselves be movable in relation to the output shaft;

Figure 3B shows a variant of Figure 3A with cross-arm or spider array carrier axles 12, each orthogonal to a single common central vertical output shaft 14; alternatively, carrier axles 12 might adopt different, even variable, pivoting or flapping, inclinations in space, again with sufficient vertical separation between tiers; a 'floating' disposition of blade carrier axle 12 to output shaft 14 could be feasible; the relative angular offset or splay of tiered blade axles 12 can contribute to overall smoothness and continuity of output and also reflects the number of tiers 25 and the packing proximity; with sufficient tier vertical spacing and/or blade disposition, blade axles 12 could be allowed to rotate freely about or with the output shaft 14, provided maintaining drive coupling to the output shaft 14, so the blade motion can be harnessed;

Figure 4A shows a multiple stacked or tiered array of opposed blades 15 set upon respective carrier axles 12, reflecting different blade carrier axle 12, and thus potential blade 15, diametral spans about a central spine output shaft 14; in this example a bulbous end-waisted side profile 'xmas-tree' format is adopted, that is with longer axles 12 at mid-height; with blade carrier axles 12 in tiers or a common plane with an isolator mounting at their junction with a vertical output shaft 14;

Figure 4B shows a variant of Figure 4A with carrier axles at different tiers set at a relative angular offset to form a cross-arm spider between successive tiers;

Figure 4C shows a cross-arm array of Figure 4B upon a tilted output shaft section 14; this allows some adjustment of blade array presentation to an impacting air flow;

Figure 5A shows an orbital or planetary development of opposed diametral blades 15 upon common carrier axles 12 set upon upright shafts 24 carried at opposite outboard ends of cross arm axle 22 from a central upright shaft 14; the blades 15 can thus undertake more complex motions in space and in doing so exert a greater and more complex variety of lever arm moment about a common centre output shaft 14; generators (not shown) could be stationed on all the upright shafts 24; in this example, two carrier axles 12, one at each side of a central spine shaft 14, carry a combined total of two pairs of two, that is four blades 15; the contribution to overall motion is contingent upon relative blade sizes and dispositions in relation to rotational axes; blades 15 might interfere, complement in contribution or remain limp;

Figure 5B shows an extrapolation of Figure 5A with an additional planetary blade layer or tier; upright satellite output shafts 34 are set upon freewheel carriers (not shown) at outboard ends of the carrier axles 12 of an underlying tier; this to allow the satellite axles 34 to remain upright while the associated carrier axle 12 rotates; the satellite shafts 34 support carrier axles 22 for other diametral opposed blades 15 set at a higher tier alongside, or at the same level as, another such elevated blade pair; again generators (not shown) could be fitted to vertical shafts, although it is convenient to extract and harness energy collectively from the central vertical shaft;

in this example two outboard blade carrier axles 12, each with blades 15 at respective outboard ends, are juxtaposed in common planes at each side of an intermediate column 24 and a central spine column 14, with six blades 15 on each side, making a total of 12 blades; overall, Figure 5B is perhaps more suited to a mobile intended for visual effect and display; such an elaborate array might better suit an executive toy mobile expression or demonstration of the blade and flow interaction;

Figures 6A through 6D depict different blade proportions, dispositions and orientations about the rotational axes; bias or balance weights (not shown explicitly, but embedded in the blade structure) can be used to achieve a settled blade disposition before displacement under impacting air flow; the blade sub-division areas and their offset from the rotational axes are considerations in whether rotation about one axis takes precedence over or predominates that about another axis, or they have equal status;

Figure 6A shows asymmetric or unequal blade sub-division or bifurcation about a horizontal axis of a a carrier axle 12; the blade proportions on each side are generally rectangular, somewhat wider in radial span than vertical depth; the radial offset from the output shaft 14 could be equal or different; the blade radial offset from the output shaft determines the leverage or moment action about that;

Figure 6B shows a variant blade array to Figure 6A, but with narrower, deeper blade proportions, again with different areas on opposite sides of a carrier axle 12;

Figure 6C shows a variant of Figure 6A with blade sub-division areas mutually cranked, canted or folded about a carrier axle 12;

Figure 6D shows a variant of Figure 6B with mutually cranked, canted or folded blade areas about a vertical axis parallel to that of the output shaft 14;

With all the variants described, the sub-division or fragmentation of blades, along with balance and stability considerations, curtail the number and relative offset of blade pairs feasible in practice; the relative benefits a few larger blades versus more smaller blades can be evaluated by empirical trial. The variability in blades, axles, shafts, mountings, movement freedoms and rotational modes is great individually, even more so collectively in permutations and combinations. This can be used for greater and more efficient energy extraction. Every blade is a potential (net) contributor, notwithstanding its attendant drag penalty, if appropriately orientated in relation to a fluid flow.

Elements and features described can be mixed and matched for particular effect. Thus, to meet space constraints, a tall slim or stubby configuration could be contrived. Similarly, blade density per volume can be varied to suit a fluid medium characteristics, such as density and viscosity. A jumbled or chaotic flow can arise internally if blades are too close. This may be to advantage in an impeller-promoted flow mixing regime.

The foregoing examples reflect an upright or vertical axis output or driven shaft, such as for a wind turbine; but other shaft orientations, say inclined to the vertical, even horizontal, might be tenable, particular for water falling under gravity in a stream or flume as a kinetic energy driving medium. Given the different densities and flow rates of air and water, it might not be feasible to intercouple wind and water flows with a common turbine configuration, but rather electrical coupling of respective turbine driven generator electrical outputs might be more feasible.

An array can be carried between bearings at opposite ends or suspended, as a freely hanging pendulum, from a gimbal mount at an upper end and contained within a floating collar at a lower end, allowing a central spine shaft to settle and self-stabilise under more complex blade and blade arm rotational modes. Some elaborate blade arrays might be more appropriate to an executive toy or mobile, where visual effect of complex and unpredictable motion is a priority over any motion energy that might be gained. Bade arrays could have a constructive generator turbine or impeller purpose, or a mobile for visual effect, an (outside) ornament feature, an executive distraction or child toy; blade gyrations could have a calming effect; self-excitation or a self-sustaining mode, might be achieved by harnessing blade motion to drive a pump or impeller in turn to direct a pressurised jet or spray of fluid on to the blades.

Blade speed or rate of rotation and acceleration of transitions can be variable. Output can be harnessed, evened-out and stored electrically, in compressed air or a head of water. Blade carrier axles could be allowed to move up and down the associated vertical shafts, subject to, or for the very purpose of, blade conflict avoidance. Similarly, blade profiles could expand or contract in span or depth, and blade position could move inboard and/or outboard of a respective carrier axle. A blade might pivot or swivel upon its carrier axle; say by using a sleeve bearing also allowing longitudinal movement along the axle. Blade behaviour is constrained by blade profile, mounting and prevailing impacting fluid flow. Blade motion can exhibit chaotic behaviour, that is unpredictable but exhibiting characteristic patterns.

In the illustrated examples, multiple blades or paddles 15 are configured for co-operative working, so their relative motion with a fluid flow stream 20 can be harnessed individually and collectively. Blade and flow interaction transfers energy either to or from the blade, respectively in generator or pump mode. For greater efficiency to this end, complex multiple modes of motion, such as rotational and/or oscillatory, are admitted. Rotation is primarily about a driving or driven axis, of input or output shaft. Secondary rotation about another axis is also used in a dual rotational mode. Linear translation, such as radial blade movement, might be admitted in an adjustable span blade pair to vary the blade action moment about an intervening central output shaft.

Blades interact with the flow and so in that regard work independently, but subject to input from any other coupled blade motion. An objective is blade motion harmony or synchronism, for a mutually complementary outcome. Blades move, more particularly rotate, while immersed continuously within a fluid stream. It is desirable to harness the blade output continuously for uninterrupted power output generation. So for a wind turbine generator it is also desirable to optimise and balance blade and wind interaction to capture and harness the wind orientation.

Individual blade orientation in relation to the flow direction can vary with rotation, or more specifically angular relationship to the flow. Blades effectively move into and out of alignment with the flow. As they do so, their contribution or productivity to generation, i.e. being driven, or driving varies. A less productive or unproductive blade interaction is a 'derogatory' drain or bleed upon the beneficial interactions of other blades, and which might otherwise have bolstered collective performance or output. So, whilst less productive relative blade orientations to the flow can be tolerated, is useful to minimise unproductive or counter productive blade to flow relative orientations.

A multiple tier or layer blade stack, such as of Figure 4A, can simply be a uniform or varied vertical, say row-by-row, repetition of a basic single tier module. Alternately or additionally, horizontal, say column-by-column, repetition can achieve a side-by-side array. A circular rotary blade path is convenient for simplicity, but other more complex (curvilinear) motion paths, such as elliptical or orbital, multiple rotary axis planetary or epicyclic forms may be employed. This could be achieved by linkages and/or a constraint pathway contour.

Blades are conveniently supported at one end, or between opposite ends, such as upon a gantry or catenary frame (not shown). Blade movement, such as pitch adjustment with angular position, is not fixed , but rather can be effected individually or collectively and in harmony or synchronism, say by a common or shared drive linkage or inter-coupled position-index actuators.

A simple or plain flat plate blade profile may suffice, but more curvilinear 2D or 3D forms and/or those with bounding edge transitions, such as upstands or winglets, can be employed. Blade profile can be fixed or variable, as can blade orientation and/or disposition. Blade 'panels' could be completely solid in-filled or selectively perforated for particular fluid interactional effect. Sub-divided, segmented , or fragmented blade forms could be employed. For example, a jigsaw lattice of minor 'bladelets' could interfit at complementary profiled edges in a lattice array. A large collective blade area can thus be achieved from modest sized constituent blade elements. Blade size can vary from a full to a partial or fragmented span, such as with a shutter slat configuration with intervening fluid flow. A multiple blade array could comprise identical, similar or diverse blade formats. A mixed-orientation diverse blade set could provide disparate flow interactions and energy transfer behaviour. A vertical axis wind turbine blade array orientation is convenient against a prevailing generally horizontal relative air flow or wind of continually variable direction, although other dispositions can be contemplated. Individual blades or paddles are orientated upright or vertical and mounted for rotation about an upright or vertical axis.

A rotary blade array can sit in an elevated stance above the ground upon a (central) support pylon (not shown), to bring the blade array into a 'beneficial' coherent upper air flow, undisturbed by closer to ground level obstacles which can generate turbulent or randomised disturbed flow or eddies. In conventional known VAWT's all blades typically remain upright throughout rotation, so not all are continually productive. Indeed some rotational stages are counter-productive. Embodiments of the present invention allow mixed and variable blade orientation. Thus, say, some blades may have vertical, whereas others horizontal, orientation. Moreover, that blade orientation can varied between blades over rotational cycles. Similarly, with a diverse blade mix, disposition and orientation.

A horizontal or inclined axis water turbine orientation can be more convenient to capture kinetic energy of water flow, of greater density than air, under an upstream gravity head or fall, in a stream, spillway or flume fed from an upstream header reservoir.

A combination wind and water turbine can use respective independent blades or blade arrays (inter-)coupled to a common output; if not a common output shaft, then say a jointly harnessed generator or motor according to the respective turbine modes. A mixed- mode combination wind and water turbine could allow, say, wind-driven pumping through a water impeller turbine. A wind module might be used to drive a pump to jet water to a water turbine module, in a mixed or multi medium feedback loop. Whilst separate wind and water turbine elements can be adapted to the interaction characteristics, aerodynamics and hydrodynamics of respective fluid media, a turbine format capable of addressing diverse fluids could be contrived, albeit with some compromise.

In a simplified arrangement, a 'leading' upright (or rather 'across-the-flow') blade, driven by impact with the flow (in generator mode), is coupled upon a common (transverse or horizontal) carrier axle with a relatively orthogonal 'trailing' blade, set aligned with the flow for minimal drag. A driven or driving blade is set generally across the flow, for 'maximum intersection', over one (half phase) part of its revolution about an upright output shaft; with a diametrically-opposed blade set aligned with the flow, for minimal interference with the flow. Blade 'flip over' from across, to alignment with, the flow could be progressive and self-setting, by the interaction of the blade array with the flow, or more abrupt or sudden, through some external mechanism responsive to variation in flow direction. A driving or driven {vis drive(n)} shaft is also upright or rather lies 'across-the-flow'. Blade shape and grouping could be adapted to minimise the 'transitional drag' in blade flip-over, or 'role-reversal' from active (driven / driving) to passive ; more generally, blade shapes and sizes could vary, albeit with some symmetry about the output shaft.

Multiple similar or differentiated blades could be set on each side of the output shaft, again with 'net effective' symmetry; a common axle for such opposed blades represents one simple blade inter-couple configuration, but other, albeit more elaborate,

arrangements could be contrived ; thus, say, with an 'all-upright' (or again 'across-the- flow') blade array, set upon upright, rather than transverse axles, non-driving blades could be 'feathered' in their traverse into the flow to reduce drag. As in some HAWT and VAWT art, for the purpose of analysis, blades could be treated as aerofoils (or hydrofoils) , so force generated equates to lift, with attendant drag penalty; blade stall arises if too abrupt an intersection with the flow, and large turbulent downstream spillover flow arises, which might impede self start of blade rotation; variable pitch props can be used as drive gearing, but an electrical load might achieve the same anchor effect. The electrical load could be resistive or reactive, that is an inductance such as a coil winding or capacitative. A generic (generator mode) statement could be to the effect that individual (paddle) blade orientation in space, or more specifically, blade presentation in relation to a fluid flow stream in which it is immersed, dictates the (drag) load upon the blade, as an impediment flow, and thus reflects the energy extracted from the flow, and available for conversion into output shaft horse power, in turn to drive an electrical generator.

Combined wind and water turbines is more challenging technology, with limited topic exploration.

aside from some wind turbine driven pumped storage for water turbine drive work. The Applicant envisages a confined channel, culvert, flute or flume in which water and boundary air flows are mutually entrained, such as with an outer air-water spray droplet energy capture, along with a water column inner core. That niche 'diversion' aside, the prime thrust of the invention remains a wind turbine role, with emphasis upon

(automated) blade pitch setting, relative disposition + orientation of blade sets. This might include contra-rotating blade sets in an axial flow stream. Well-established aircraft propeller and rotary wing technology allows blade pitch adjustment; also noted are directional thruster marine drives for submersibles.

Blade carrier axles and/or output shafts could be inclined, canted or pivoted, for continual adjustment of disposition, rather in the manner of rotary wings, for more effective interaction with a flow; blades could be weight biassed, such as with tip or edge weights, to favour certain default orientations.

Blade panel infill could be solid or part perforated, such as of mesh, to allow a proportion of fluid bleed through the blade to promote blade movement stability or certain rotation modes, such as by resolving a tendency to dither or flutter. An adjustable such bleed could be achieved, such as be a movable solid closure or blanking panel or slats over a perforated portion. An adjustable tension stretch mesh could also be contrived to vary individual and collective mesh aperture shape and size.

Flow through the blade body, even if sacrificing some blade impetus, could be used constructively to influence flow over and around the blade as the primary means of achieving blade thrust. Permeable or perforated blade though-flow might also be deployed as an overload safety 'fuse' or damping measure to counter excessive sudden wind gust loads. Variable blade permeability could be implemented to speed up or slow down blade motion in varying wind conditions. A blade array as disclosed for ambient wind power might also be adapted for water turbine power, by wholesale immersion in a water pool, tank or stream or local impact with a directed water jet , cascade or flume from a head of water in a weir, reservoir pool or tank.

A differential continuous or incrementally varying blade pitch or orientation over a blade longitudinal span, such as a progressive twist or curl could help more effective blade presentation and response to varying wind direction. A similar consideration could be applied to the longitudinal blade profile, with departure from a straight radial to segmented polygonal or curved arc, This could apply to 'fatter' stubby or squat paddle or more readily to slender strip blade forms. Twisted, curled or furled blades from internested blade array with intermeshed 'turbine spool' blades coming into close proximity might induce a beneficial local intervening 'pulsating charged' flow swirl characteristic to promote blade and flow interaction and blade drive.

Initial hesitancy or reluctance in blade motion, exhibited as stationary, sporadic twitch, random dither or flutter could be self-sustaining or reinforcing, resulting in an effectively stalled blade mode with attendant chaotic flow swirl around the blade and drag, but which can be resolved or overcome once motion has started; so a 'kick-start' or jerk impetus can be helpful to this end. Once motion is underway, individual and collective blade momentum helps it continue under a steady uninterrupted un-stalled coherent laminar flow.

In ambient air, not all blades in an initially stationary array necessarily start to move together. Rather it may require motion of a blade assembly or array to promote movement of individual blades on their own individual account. Only then can multiple blade cluster motion be harnessed. An array of blades each acting independently is tenable if each blade motion energy can be captured and converted.

A diversity of blade behavioural modes can be tolerated for productive purpose, A continuum of mode change is also tenable, even if the individual or collective output varies, as this can be compensated electrically if all blade output energy is converted into electrical storage. A more esoteric blade form could be 'hollow' fluted and/or an 'open' twist, better to capture flow eccentricities or eddies.