A combustion engine including at least one combustion chamber, a first bleed air supply fluidly coupled to a portion of the combustion engine upstream the combustion chamber, a second bleed air supply fluidly coupled to a portion of the combustion engine downstream the combustion chamber, a first thermal bus, and a turbomachine including a compressor, a rotary pump, and a first turbine, with the compressor and rotary pump in serial flow arrangement and the rotary pump being fluidly coupled to the first thermal bus.