The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have a first hub disposed thereon with a plurality of cavities. At least one contour is slidably received into an arcuate cavity in an exterior surface of the hub. The contour has a convex outer surface that cooperates with an inwardly facing curved surface of a housing to form a working volume.

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have a first hub disposed thereon with a plurality of cavities. At least one contour is slidably received into an arcuate cavity in an exterior surface of the hub. The contour has a convex outer surface that cooperates with an inwardly facing curved surface of a housing to form a working volume.

A compound engine assembly for use as an auxiliary power unit for an aircraft and including an engine core with internal combustion engine(s), a compressor having an outlet in fluid communication with an engine core inlet, a bleed conduit in fluid communication with the compressor outlet through a bleed air valve, and a turbine section having an inlet in fluid communication with the engine core outlet and configured to compound power with the engine core. The turbine section may include a first stage turbine having an inlet in fluid communication with the engine core outlet and a second stage turbine having an inlet in fluid communication the first stage turbine outlet. A method of providing compressed air and electrical power to an aircraft is also discussed.

A compound engine assembly for use as an auxiliary power unit for an aircraft and including an engine core with internal combustion engine(s), a compressor having an outlet in fluid communication with an engine core inlet, a bleed conduit in fluid communication with the compressor outlet through a bleed air valve, and a turbine section having an inlet in fluid communication with the engine core outlet and configured to compound power with the engine core. The turbine section may include a first stage turbine having an inlet in fluid communication with the engine core outlet and a second stage turbine having an inlet in fluid communication the first stage turbine outlet. A method of providing compressed air and electrical power to an aircraft is also discussed.

A method of operating an engine assembly receiving fuel, including admitting atmospheric air at a temperature T.sub.1 through an inlet of a compressor having a pressure ratio of PR.sub.GT, compressing the air in the compressor, cooling the compressed air from the compressor through an intercooler to cool the air from a temperature T.sub.BIC to a temperature T.sub.AIC, delivering the cooled compressed air from the intercooler to an inlet of an intermittent internal combustion engine having an effective volumetric compression ratio r.sub.VC, and further compressing the air in the intermittent internal combustion engine before igniting the fuel, where ${\left({\mathrm{PR}}_{\mathrm{GT}}\right)}^a{\left(r_{\mathrm{VC}}\right)}^b\left(\frac{T_{\mathrm{AIC}}}{T_{\mathrm{BIC}}}\right)\left(\frac{T_1}{T_A}\right)<1.$
An engine assembly is also discussed.

A method of operating an engine assembly receiving fuel, including admitting atmospheric air at a temperature T.sub.1 through an inlet of a compressor having a pressure ratio of PR.sub.GT, compressing the air in the compressor, cooling the compressed air from the compressor through an intercooler to cool the air from a temperature T.sub.BIC to a temperature T.sub.AIC, delivering the cooled compressed air from the intercooler to an inlet of an intermittent internal combustion engine having an effective volumetric compression ratio r.sub.VC, and further compressing the air in the intermittent internal combustion engine before igniting the fuel, where ${\left({\mathrm{PR}}_{\mathrm{GT}}\right)}^a{\left(r_{\mathrm{VC}}\right)}^b\left(\frac{T_{\mathrm{AIC}}}{T_{\mathrm{BIC}}}\right)\left(\frac{T_1}{T_A}\right)<1.$
An engine assembly is also discussed.

A rotary engine that starts and operates on compression-ignition of a heavy fuel without a secondary ignition source. The rotary engine includes a rotor housing that forms an epitrochoidal-shaped chamber having linear side portions extending between rounded end portions. A three-flanked rotor is disposed in the chamber to rotate and operate in a manner similar to that of a common Wankel-style rotary engine. The rotor and chamber are configured to provide a compression ratio sufficient to produce compression-ignition of a heavy fuel. The rotor includes apex seal and side seal mounting blocks formed from hardened materials and that are simply removable from the rotor for replacing apex and side seals. The apex seals may include multiple non-parallel seal members at each apex and the apex seals and the side seals may overlap or intersect a corner seal to increase sealing under high compression loads produced by the rotor/chamber configuration.

A rotary internal combustion engine (ICE) has: a housing defining a rotor cavity; a rotor received within the rotor cavity to define working chambers of variable volume around the rotor, the rotor having circumferentially spaced peripheral apex seals biased radially outwardly in sliding engagement against a peripheral wall of the housing to separate the working chambers from one another, the housing having a fluid passage defined therethrough and opening into an inner surface of the peripheral wall; and an injector having a lubricant inlet hydraulically connected to a lubricant source, an actuation inlet hydraulically connected to a source of an actuation fluid, and a lubricant outlet, the injector having an open state in which the lubricant outlet is in fluid flow communication with the fluid passage upon the actuation fluid received within the injector and a closed state in which the lubricant outlet is disconnected from the fluid passage.

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have a first hub disposed thereon with a plurality of cavities. At least one contour is slidably received into an arcuate cavity in an exterior surface of the hub. The contour has a convex outer surface that cooperates with an inwardly facing curved surface of a housing to form a working volume.

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have a first hub disposed thereon with a plurality of cavities. At least one contour is slidably received into an arcuate cavity in an exterior surface of the hub. The contour has a convex outer surface that cooperates with an inwardly facing curved surface of a housing to form a working volume.