Abstract: Apparatus, systems, and articles of manufacture are disclosed to power thermal management systems with heat of a working fluid therein. Example thermal management system include: a thermal transport bus loop fluidly coupled to at least one heat source exchanger and at least one heat sink exchanger; a turbomachine including a turbine and a compressor, the turbine and compressor rotatably interlocked via a shaft, the compressor coupled to the thermal transport bus loop, the turbine including an inlet and an outlet, the inlet connected to a first point of the thermal transport bus loop via a first flowline, the outlet connected to a second point of the thermal transport bus loop via a second flowline; and a control valve coupled to the first flowline, the control valve to adjust a mass flowrate of the heat exchange fluid in the first flowline based on a speed of the shaft.

Abstract: Casing waste heat recirculation loops and related methods are disclosed. An example engine includes at least one of a compressor or a pump; a casing for at least one of the pump or the compressor, the casing including a conduit formed in a wall of the casing, the conduit to define a recirculation flow path for a fluid at least partially within the wall of the casing; a valve positioned at an inlet to the recirculation flow path; and an actuator operatively connected to the valve and configured to adjust a position of the valve among at least one of open, partially open, or closed, the valve to allow passage of at least a portion of the fluid when at least one of open or partially open.

Abstract: Apparatus, systems, and articles of manufacture are disclosed to power thermal management systems with heat of a working fluid therein. Example thermal management system include: a thermal transport bus loop fluidly coupled to at least one heat source exchanger and at least one heat sink exchanger; a turbomachine including a turbine and a compressor, the turbine and compressor rotatably interlocked via a shaft, the compressor coupled to the thermal transport bus loop, the turbine including an inlet and an outlet, the inlet connected to a first point of the thermal transport bus loop via a first flowline, the outlet connected to a second point of the thermal transport bus loop via a second flowline; and a control valve coupled to the first flowline, the control valve to adjust a mass flowrate of the heat exchange fluid in the first flowline based on a speed of the shaft.

Abstract: Dual compression-expansion pumps and related methods are disclosed. An example fluid pump includes a shaft, a motor coupled to the shaft, the motor to drive a rotation of the shaft, a compressor coupled to a first end of the shaft, a turbine coupled to a second end of the shaft opposite the first end, and a housing including a first inlet, a second inlet, a third inlet, a first outlet, and a second outlet, the first outlet fluidly coupled to the second inlet, the second outlet fluidly coupled to the third inlet.