PURPOSE: To increase the flowing quantity of gas based on constant-volume combustion, generate a large amount of constant-volume heated working gas and heighten output, by combining a turbine running gas generator with a rotation chamber combustion mechanism for continuously performing constant-volume heating combustion.

CONSTITUTION: Gas introduced through a gas intake port is compressed by a compressor 2. Fuel is injected from a fuel injection valve 3 into the compressed gas while it flows through a compression passage 4. The gas and the fuel are thus mixed with each other. The mixture is introduced into the rotation chamber 11 of a feed rotor 9 which rotates in a casing 7. The introduced mixture is moved as the rotor 9 rotates. When the mixture is burned and exploded under the pressure of high- temperature gas from a combustion assisting chamber 12, heated and expanded high-pressure gas gushes to heighten the pressure of the combustion assisting chamber 12. At that time, high-speed gas ejection is caused from a working gas ejection passage 14 to drive a turbine 15. Some gas remaining in the rotation chamber 11 is discharged into the atmosphere through an exhaust port 6.