A compound cycle engine having at least one rotary unit defining an internal combustion engine, a first stage turbine in proximity of each unit, and a turbocharger is discussed. The exhaust port of each rotary unit is in fluid communication with the flowpath of the first stage turbine upstream of its rotor. The rotors of the first stage turbine and of each rotary unit drive a common load. The outlet of the compressor of the turbocharger is in fluid communication with the inlet port of each rotary unit, and the inlet of the second stage turbine of the turbocharger is in fluid communication with the flowpath of the first stage turbine downstream of its rotor. The first stage turbine has a lower reaction ratio than that of the second stage turbine. A method of compounding at least one rotary engine is also discussed.

A pulse combustion heat exchanger having a longitudinal axis is configured to accept oxidant and fuel and output a cooled combustion stream. The pulse combustion heat exchanger includes an oxidant inlet section that accepts oxidant, a fuel inlet section that accepts fuel, a mixing section that mixes oxidant with fuel, a combustion section that receives the oxidant and fuel and produces a pulsating combustion stream, and a heat transfer section configured to receive the pulsating combustion stream, the heat transfer section includes one or more resonance conduits. Coolant is employed at a plurality of longitudinally spaced-apart transition sections to remove heat.

Disclosed herein are several embodiments for shroud arrangements to be used in rotary engines using a plurality of rotors within the shroud arrangement. At least one of the rotors is not fixed to the shroud.

Disclosed herein are several embodiments for shroud arrangements to be used in rotary engines using a plurality of rotors within the shroud arrangement. At least one of the rotors is not fixed to the shroud.

A compound cycle engine having an output shaft, at least two rotary units each including an internal combustion engine with the rotor of each rotary unit mounted on the output shaft and in driving engagement therewith, and a turbine including a rotor in driving engagement with the output shaft. The exhaust port of each rotary unit housing is in fluid communication with the flowpath of the turbine upstream of its rotor. The turbine is disposed co-axially between two of the rotary units. The engine may further include a compressor in fluid communication with the inlet port of each housing and a second turbine having an inlet in fluid communication with the flowpath of the first turbine downstream of its rotor. A method of compounding rotary engines is also discussed.

A compound cycle engine having an output shaft, at least two rotary units each including an internal combustion engine with the rotor of each rotary unit mounted on the output shaft and in driving engagement therewith, and a turbine including a rotor in driving engagement with the output shaft. The exhaust port of each rotary unit housing is in fluid communication with the flowpath of the turbine upstream of its rotor. The turbine is disposed co-axially between two of the rotary units. The engine may further include a compressor in fluid communication with the inlet port of each housing and a second turbine having an inlet in fluid communication with the flowpath of the first turbine downstream of its rotor. A method of compounding rotary engines is also discussed.

An engine assembly including an internal combustion engine, an impulse turbine, and an exhaust pipe providing fluid communication between the exhaust port of the internal combustion engine and the flow path of the turbine. The exhaust pipe terminates in a nozzle. A ratio Vp/Vd between the pipe volume Vp and the displacement volume Vd of the internal combustion engine is at most 1.5. A minimum value of a cross-sectional area of the exhaust pipe is defined at the nozzle. In one embodiment, a ratio An/Ae between the minimum cross-sectional area An and the cross-sectional area Ae of the exhaust port of the internal combustion engine is at least 0.2. A method of compounding at least one internal combustion engine is also discussed.

An engine assembly including an internal combustion engine, an impulse turbine, and an exhaust pipe providing fluid communication between the exhaust port of the internal combustion engine and the flow path of the turbine. The exhaust pipe terminates in a nozzle. A ratio Vp/Vd between the pipe volume Vp and the displacement volume Vd of the internal combustion engine is at most 1.5. A minimum value of a cross-sectional area of the exhaust pipe is defined at the nozzle. In one embodiment, a ratio An/Ae between the minimum cross-sectional area An and the cross-sectional area Ae of the exhaust port of the internal combustion engine is at least 0.2. A method of compounding at least one internal combustion engine is also discussed.

Aircraft power plants and associated methods are provided. A method for driving a load on an aircraft includes: transferring motive power from an internal combustion (IC) engine to the load; discharging a flow of first exhaust gas from the IC engine when transferring motive power from the IC engine to the load; receiving the flow of first exhaust gas from the IC engine into a combustor; mixing fuel with the first exhaust gas in the combustor and igniting the fuel to generate a flow of second exhaust gas; receiving the flow of second exhaust gas at a turbine and driving the turbine with the flow of second exhaust gas from the combustor; and transferring motive power from the turbine to the load.

Disclosed herein is an indexing system for a rotor assembly where in one example the indexing system regulates the rotational location of drive rotors. In one example the rotors are configured to rotate about a shaft.