Thermal compression reheating cycle
A disclosed turbine engine assembly includes a core engine assembly generating an exhaust gas flow and a thermal compressor where the exhaust gas flow from the core engine is received and compressed. The thermal compressor includes a converging duct that recompresses the exhaust gas flow that is mixed with fuel in a secondary combustor and ignited to generate a reheated gas flow.
1 . A turbine engine assembly comprising: a core engine assembly generating an exhaust gas flow; a thermal compressor where the exhaust gas flow from the core engine is received and compressed, the thermal compressor comprising a static converging duct where the exhaust gas flow is recompressed and cooled without input power and moving components, wherein the thermal compressor includes walls with at least one passage for a flow of a cooling medium for cooling the exhaust gas flow, the at least one passage is separate from the static converging duct for the exhaust gas flow; wherein the converging duct includes a forward end with a cross-sectional flow area larger than a cross-sectional flow area of an aft end, wherein the recompressed exhaust gas flow is exhausted through the aft end and communicated to a secondary combustor, wherein the cooling passages include an inlet disposed proximate the aft end and an outlet disposed proximate the forward end; the
a secondary combustor where fuel is mixed with the recompressed exhaust gas flow from the thermal compressor and ignited to generate a reheated gas flow; and a secondary turbine section where the reheated gas flow is expanded to generate shaft power.
2 . The turbine engine assembly as recited in claim 1 , wherein the converging duct is in thermal communication with the cooling medium for cooling the exhaust gas flow as it flows through the at least one passage for the flow of the cooling medium within the walls of the thermal compressor.
3 . The turbine engine assembly as recited in claim 2 , including an expansion turbine where heated cooling medium is expanded to drive an auxiliary shaft.
4 . The turbine engine assembly as recited in claim 3 , wherein the cooling medium comprises a fuel flow from a fuel system and fuel exhausted from the expansion turbine is communicated to at least one of a combustor of the core engine and the secondary combustor.
5 . The turbine engine assembly as recited in claim 1 , wherein the thermal compressor is disposed along an engine longitudinal axis common with the core engine assembly.
6 . The turbine engine assembly as recited in claim 1 , wherein the thermal compressor is disposed outside of a core flow path of the core engine assembly.
7 . The turbine engine assembly as recited in claim 1 , wherein the thermal compressor is disposed outside of a core flow path and an amount of exhaust gas flow that is less than the total exhaust gas flow exhausted from the core engine is communicated through a duct to the thermal compressor.