| I claim: 1. In combination with a conveyance adapted to travel through a fluid, a duct through which a portion of the fluid which contacts the upstream end of said conveyance flows, said duct having an inlet, a convergent-divergent nozzle downstream of said inlet, a first component having a passageway which increases in cross-section downstream thereof and an outlet from which said fluid portion discharges from said duct. 2. The combination as claimed in claim 1 wherein said duct further includes a second component situated downstream of said first component, said second component having a uniform cross-section throughout its length. 3. The combination as claimed in claim 2 said wherein said first and second components are adjacent to each other such that said fluid portion which discharges from said first component passes directly into said second component. 4. The combination as claimed in claim 1 wherein said outlet has a curved inner wall which increases in cross-section downstream thereof such that said fluid portion which discharges through said outlet and which is adjacent to said inner wall tends to adhere to the latter said wall by reason of the Coanda effect. 5. The combination as claimed in claim 1 wherein said convergent-divergent nozzle is adjacent to said inlet. 6. The combination of claim 1 wherein said duct is curved such that said fluid which discharges from said outlet flows downstream of said outlet along an outer wall of said compartment. 7. In combination with a conveyance having an upstream end and oppositely facing sides downstream of said upstream end, said conveyance being adapted to travel through a fluid, a pair of ducts through which portions of the fluid which contact the upstream end of said conveyance flow, said ducts each having an inlet at said upstream end, a convergent-divergent nozzle downstream of said inlet, a first component having a passageway which increases in cross-section downstream thereof and an outlet from which said fluid portion discharges, said outlets being on opposite sides of said conveyance. 8. The combination of claim 7 wherein said conveyance has a longitudinally extending plane of symmetry, said ducts being symmetrically disposed on opposite sides of said plane. 9. In combination with a conveyance having upstream and downstream ends and oppositely facing sides, said conveyance being adapted to travel through a fluid, a pair of ducts through which portions of the fluid which contacts the upstream end of said conveyance flow, said ducts each having an inlet at said upstream end, a convergent-divergent nozzle downstream of said inlet, a first component having a passageway which increases in cross-section downstream thereof and an outlet from which said fluid portion discharges, said outlets being at the downstream end of said conveyance. 10. The combination of claim 7 wherein said conveyance has a longitudinally extending plane of symmetry, said ducts being symmetrically disposed on opposite sides of said plane. 1 1. The combination of claim 10 further including a pair of manifolds on opposite sides of said plane of symmetry, said receiving ducts on each side of said plane of symmetry terminating at a separate said manifold, a discharge duct which extends from each said manifold and terminates at a separate said outlet on the same side of the plane of symmetry as the manifold from which said discharge duct extends. 12. The combination of claim 1 1 wherein each said receiving duct has a component of generally uniform cross-sectional area, said cross-sectional areas of said components of all said receiving ducts which terminate at said separate manifold equalling the cross-sectional area of said outlet of said discharge duct which extends from said separate manifold. 13. In combination with an airship, a multi-stage duct through which a portion of the air which contacts the upstream end of said airship flows, said duct having an inlet, a first convergent-divergent nozzle downstream of said inlet, an intermediate component of uniform cross- section throughout its length, a second convergent-divergent nozzle downstream of said intermediate component and an outlet from which said air portion discharges from said duct. 14. The combination of claim 13 further including a vertically extending rudder into which said air portion discharges from said duct. 15. The combination of claim 13 further including a fan disposed within said intermediate component for increasing the velocity of air which flows through said duct. 16. The combination of claim 13 wherein said airship has a generally spherical outer wall. |
DUCT FOR HARNESSING ENERGY FROM FLUID THROUGH WHICH CONVEYANCE PASSES
Field of the Invention
This invention relates to an assembly for harnessing the energy of the fluid through which a conveyance on land, air or water moves and more particularly to a duct which provides a passageway for a portion of the fluid through which a conveyance such as a ship, motor vehicle, train or airship travels. The duct serves not only to improve the efficiency of fuel required to power the conveyance but also to reduce the output of pollutants generated as the fuel is consumed.
Background of the Invention
As is well known, the air through which a motor vehicle or train travels acts as a drag or obstruction to its progress. Similarly the air through which an airship such as a dirigible travels impedes its progress as does water through which a ship travels. The aerodynamic or hydro- dynamic drag adds significantly to the quantity of fuel that is needed to propel the conveyance. As well more pollutants such as greenhouse gases are released to the atmosphere or water than would otherwise be the case if there were no such drag.
I have found that if a portion of the air through which a motor vehicle travels is directed into a duct which extends from the front of the vehicle to its sides, top, bottom or rear, the duct, provided it is of a particular structure, significantly improves the performance of the vehicle. There are a number of reasons for this: first, air which passes through the duct increases in velocity as it passes through the duct and exits at a significantly higher velocity than its velocity at its intake. The exiting stream of air increases the forward motion of the vehicle with resulting improved efficiency of the fuel used to power the vehicle and reduction in the volume of pollutants released to the atmosphere. Secondly, the exiting stream of air, as it passes by the outer surface of the vehicle downstream of the duct outlet improves the aerodynamic profile of the outer surface with further improvement in fuel efficiency.
A third reason why the duct improves the performance of a motor vehicle is that the frontal area of the vehicle is decreased by the area of the intake of the duct and the more ducts there are and the larger the cross-sectional area of the ducts, of course, the greater the reduction in the frontal area. The smaller the frontal area, the lower the aerodynamic drag caused by it with resulting savings in fuel and enhanced performance of the vehicle.
Advantages similar to those mention above are achieved by means of one or more ducts which extend from the bow of a ship and terminate at its side or rear and one or more ducts which extends from the forward end of an airship and terminates at its side or its rear. Such ducts will enhance the fuel efficiency of the ship or airship and will also reduce the amount of pollutants which are released to the water or the atmosphere
Summary of the Invention
Briefly, the duct of my invention has an inlet and a convergent-divergent nozzle downstream of the inlet. Downstream of the nozzle is a first component having a passageway which increases in cross-section downstream. The duct has an outlet from which fluid flowing through the duct discharges.
Description of the Drawings
The duct of my invention is described with reference to the accompanying drawings in which:
Figure 1 is a perspective view of the duct of the invention;
Figure 2 is a section of the duct of Figure 1 ;
Figure 3 is an elevation of a second embodiment of the duct of the invention;
Figure 4 is an elevation of a third embodiment of the duct;
Figure 4a is an elevation of a fourth embodiment of the duct;
Figure 5 is a perspective view of a ship fitted with a pair of ducts of the invention, the ducts being shown in phantom lines;
Figure 6 is a section of a ship from above having a duct which extends along the longitudinal axis of the ship;
Figure 7 is an elevation of the front end of the ship of Figure 6;
Figure 8 is a section of a ship from above having a pair of ducts which extend from the front end to opposite side walls of the ship;
Figure 9 is an elevation of the bow of the ship of Figure 8;
Figure 10 is a section of the bow of a ship from above having a flat front end fitted with a pair of ducts of the invention;
Figure 1 1 is an elevation of the front end of the ship of Figure 10;
Figure 12 is a section of the bow of a catamaran in which each hull is fitted with a separate duct of the invention;
Figure 13 is an elevation of the front ends of the catamaran of Figure 12;
Figure 14 is a elevation of the front end of the ship of Figure 15;
Figure 15 is a section of a ship from above having a pointed front end fitted with a pair of ducts of the invention;
Figure 16 is an elevation of the front end of a ship fitted with eight ducts of the invention; Figure 17 is an elevation, partly in section, of a dirigible fitted with a single duct of the invention;
Figure 18 is a perspective view of a motor vehicle fitted with a pair of ducts of the invention;
Figure 19 is a perspective view of a tractor trailer fitted with three ducts of the invention; in a compartment above the driver's cab;
Figure 20 is an enlarged perspective view of the compartment of Figure 19 showing the ducts in phantom lines;
Figure 21 is an elevation of the rear portion of the tractor trailer;
Figure 22 is a horizontal section of a ship similar to that illustrated in Figure 14;
Figure 23 is a horizontal section of a ship similar to that illustrated in Figure 16;
Figure 24 is an elevation of a dirigible having a two stage duct and a fan within the duct; and
Figure 25 is an elevation of a spherical dirigible having a two stage duct.
Like reference characters refer to like parts throughout the description of the drawings.
Description of Preferred Embodiments
With reference to Figures 1 and 2, the duct of my invention, generally 30, has an upstream end 32 and a downstream end 34. A conventional convergent-divergent nozzle 36 defines the inlet of the duct at the upstream end. Downstream of the nozzle is a first component, generally 38, having a passageway 40 which increases in cross-section in a downstream direction. The first component terminates at an outlet 42.
The inner wall 36a of nozzle 36 immediately upstream of its throat 46 where its cross- sectional area is least lies on a tangent 48. The angle between the tangent and the longitudinal axis 50-50 of the duct, identified as 52, is preferably in the range of about 10 to about 15 degrees.
Outlet 42 has a curved inner wall 54 which enlarges in cross-section downstream of the duct such that fluid which discharges through the outlet and which is adjacent to the inner wall (identified by the arrows 56) tends to adhere to the inner wall by reason of the Coanda effect.
With reference to Figure 3, the illustrated duct is the same as the duct depicted in the previous figures except that the duct has a second component 62 between the first component 64 and outlet 66. The first component and the nozzle are the same as the first component and outlet of Figures 1 and 2. The cross-sectional area of the passageway 68 formed in the second component is uniform throughout its length and at outlet 66.
The length or area ratio of the first component measured from the throat of the nozzle to its junction with the second component controls the velocity of fluid which discharges from the outlet of the duct. For most applications, the length of the first component section is in the range of about 5 to about 10 times the diameter of the nozzle at its throat.
The duct of Figure 4 is the same as that of Figure 3 in that passageway 71 within second component 70 has a uniform cross-section. Where it differs is that its outlet 70a is curved outward to achieve a Coanda effect.
With reference to Figure 4A, the duct is composed of first and second components 76a,b which are the same as the first and second components of Figure 3. The duct has additional third, fourth and fifth components 76c,d and e. The third and fifth components are the same as component 64 of Figure 3 and the fourth component is the same as component 70 of Figure 4. The duct of Figure 4A forms a multi-stage assembly, the first stage being component 76a, the second stage being component 76c and the third being component 763. The duct would suitable in the ships illustrated in Figures 6 - 1 1 , the catamaran illustrated in Figures 12 and 13 and the dirigible illustrated in Figure 17.
With reference to Figure 5 a pair of ducts extends from inlets 74 at the upstream end or front end 76 of a ship 78 and terminate at outlets 82a, 84a on opposite side walls of the vessel. The ducts have first components 72a,b of increasing inner diameters and second components 82,84 of uniform inner diameters. The ducts are disposed symmetrically about the longitudinal axis 90-90 of the ship and their inlets as well as their outlets are beneath the water line 92 of the vessel.
The ducts of Figure 5 are of the same construction as the duct illustrated in Figure 4 except that they are curved. The curvature should be smooth so that it does not inhibit the free flow of water through the duct. Preferably the curvature throughout the length of the duct should not exceed about 30 degrees for optimum flow conditions.
In Figures 6 and 7, duct 100 commences at the front edge 102 of ship 104 and terminates at its stern 106. The duct is straight and its longitudinal axis lies on the longitudinal axis 104a- 104a of the vessel. The duct is of the same structure as the duct of Figure 4, having first and second components 1 10, 1 12 and an inlet 1 14 and an outlet 116. The first component 1 10 is relatively short while the second component 1 12 is elongated and extends to the outlet 1 16 at the rear of the ship.
In Figures 8 and 9, the ducts are generally straight unlike those illustrated in Figure 5 but otherwise the ducts are the same. The ducts extend from inlets 120 at the front edge of the vessel to outlets 122 at the side walls. The angle of the ducts is such that the water which discharges from the outlets is directed along the side walls of the vessel. The direction of the flow of water is indicated by the arrows in Figure 8.
Figures 10 and 1 1 illustrate a ship having a front edge 140 which is flat and perpendicular to the direction of travel of the vessel except for the curved side edges 142 of its front edge. The configuration of the bow is typical of that of a barge or a scow. Arrows indicate the direction of flow of water as it travels from the inlets 144 at the front end to the outlets 146 at the side walls of the vessel.
In Figures 12 and 13, vessel 150, is a catamaran having twin hulls 152 in parallel with one another. The bow of each hull has an inlet 154 of a duct 156 which extends to an outlet 158 in the space 160 between the two hulls. Water from the bows of the craft enters the inlets and flows in the direction of the arrows and discharges into space 160. It will be seen that the water flows along the inside wall of the hull in which the outlet is formed.
In Figures 14 and 15, a pair of inlets 166 is provided at the forward end of a ship having a generally pointed bow 168 and a rounded stern 170. Water flows through the inlets and straight back in the direction the arrows. Each duct curves outward as it approaches outlet 172 where the stern of the vessel meets one of its side walls. The ducts direct the flow of water from the outlets in a direction parallel to the longitudinal axis so that, in most cases, the flow will be parallel to the direction of movement of the vessel.
In Figure 16, a bow 174 of a large vessel such as an ocean liner, battleship or aircraft carrier has four inlets 176 on each side wall 174a,b of its front end. Many inlets serve to reduce the area of the forward end of the vessel and hence the drag to its forward movement. The inlets vary in diameter from a maximum 176a nearest to the forward edge 180 of the bow to a minimum 176b furthest from the forward edge. The largest quantity of water will accordingly flow through the pair of inlets 176a and the least through the pair of inlets 176b. It will be understood that fewer or more ducts can be formed in the front end of the vessel and their inside diameters can vary. The inside diameters can be all the same or vary as desired.
It will be observed that all of the ducts in the vessels illustrated in Figures 4 to 15 are symmetrically disposed about the longitudinal axes of the vessels.
In Figure 17 a dirigible 180 has a straight duct 182 which is coaxial with the longitudinal axis 180a- 180a of the airship. The cross section of the duct increases downstream of the air inlet 184 to a point 186 approximately one third the length of the airship. From that point to the outlet 188 of the duct, its cross-section remains the same.
In Figure 18 a pair of ducts (not visible) extend from inlets 192 at the front of a motor vehicle to outlets 194 on its side walls. The ducts are curved in the same way as are the ducts illustrated in Figures 8, 9 and 10.
In Figures 19 and 20, three ducts 200a,b and c are mounted in a compartment 202 located above the driver's cab 204 of a tractor trailer 206. The three ducts have inlets 208a,b and c for air on the front wall of the compartment. The central inlet 208a opens into duct 200a which curves upwardly and terminates at an outlet 210 on the roof of the compartment. The two other inlets 208b,c on either side of the central inlet open into ducts 200b,c which curve outwardly and terminate at outlets 208b,c on opposite sides walls of the compartment.
The ducts and the outlets are shaped such that air which discharges from the outlets flows along the side walls and the upper wall of the freight compartment as illustrated by arrows in Figure 19 and around the rear of the freight compartment as illustrated by arrows in Figure 21. The direction of flow should have a maximum horizontal component and a minimum vertical component.
Air inlets 220, 222 are also formed on the front bumper and the front grille of the vehicle and outlets 224, 226 are formed in the two side walls of the cab and upstream of the wheels beneath the freight compartment as illustrated in Figure 1 .
With reference to Figure 22 the ducts on each side wall of the vessel illustrated in Figure 16 extend to a pair of manifolds 240, 242. Discharge ducts 244, 240 extend from the manifolds to outlets 248, 250 in opposite side walls of the hull. Receiving ducts 246a,b,c,d extend from inlets 176 of the ship to the two manifolds and each receiving duct 246 is of the same
construction as the ducts illustrated in Figure 3.
With reference to Figure 23, the receiving ducts 246-1 which extend from the inlets 176-1 of the ship are each of the same construction as ducts 176 in Figure 22. Discharge ducts 252, 254 extend from manifolds 256, 258 to outlets 260a,b, 262 in the bottom wall of the hull.
The cross-sectional areas of the second components of all the receiving ducts which feed into a single manifold are preferably equal to the cross-sectional area of the outlet of the duct which extends downstream from the manifold. Thus in Figure 22, the cross-sectional area at outlet 248 is preferably equal to the sum of the cross-sectional areas, measured at points e,f of the second components of receiving ducts 246a,b. Similarly, the sum of the cross-sectional areas at points g,h,i,j of all the receiving ducts 246-1 in Figure 23 are preferably equal to the two cross- sectional areas of outlets 260a,b.
The ducts, manifolds and outlets of Figures 22 and 23 are shaped such as to achieve a laminar flow of water through them and to cause the water which discharges from the outlets to flow along the walls of the hull downstream of the outlets in order to obtain maximum benefit from the water flow.
With reference to Figure 24, the illustrated airship or dirigible, generally 300, has a duct 302 which extends longitudinally along the central axis of the airship. The duct has two stages 304, 306 each having a convergent-divergent nozzle downstream of its inlet. The two stages are separated by an intermediate component 308 of uniform cross-section throughout its length. Mounted within the central component is an electrically powered fan 310 which functions to accelerate the velocity of the flow of air through the duct. Air from the duct discharges onto a conventional vertically oriented rudder 312 positioned downstream of upper and lower tail wings 314. The rudder functions not only to steer the airship but as a multi-direction thruster and brake.
In Figure 25, the dirigible 320, is generally spherical in shape. Duct 322 extends longitudinally along the central axis of the aircraft and is composed of two stages 324, 326 each having a convergent-divergent nozzle downstream of its inlet. Air from the duct discharges onto a vertical rudder 328 which, like rudder 312 of the previous figure functions not only to steer the airship but as a multi-direction thruster and brake.
It will be understood, of course, that modifications can be made in the structure of the ducts and the vehicles to which they are connected without departing from the scope and purview of the invention as defined in the appended claims. For example, the cross- section of the ducts, inlets and outlets may have various curved shapes such as ellipsoidal and elliptical closed curves. Shapes having sharp corners such as square or rectangular are generally not preferred because such shapes cause fluids which flow through them to break into a number of non-parallel streams which collide with each other with resulting reduction in the velocity of the flow. Shapes which produce a laminar flow of the fluids is preferred.