An SMA actuator assembly (1a) for driving or rotating a movable part (20) in a predetermined direction or sense by a plurality of repeated incremental steps is provided. The SMA actuator assembly comprises the movable part; a first engagement portion (31) for engaging the movable part; two SMA wires (41, 42) arranged to move the first engagement portion such that the first engagement portion repeatedly, for each of said incremental steps, is configured to do the following: engage with the movable part from a starting position, exert a force or torque on the movable part in the predetermined direction and disengage from the movable part and return to the starting position. The exertion of the force or torque on the movable part and the engaging or disengaging with the movable part are caused by contraction or relaxation of the two SMA wires.

An aircraft propulsion system includes a core engine assembly that generates an exhaust gas flow, a bottoming cycle that includes a bottoming fluid flow that is expanded through a bottoming turbine, a first heat exchanger where heat from the exhaust gas flow is transferred to heat the bottoming fluid flow, and a second heat exchanger where heat from a secondary heat source is transferred to heat the bottoming fluid flow. The second heat exchanger is disposed upstream of the first heat exchanger such that heat from the secondary heat source preheats the bottoming fluid flow prior to accepting heat from the exhaust gas flow in the first heat exchanger.

Energy recovery device and method for recovering energy comprising an engine comprising a plurality of elongated Shape Memory Alloy (SMA) elements or Negative Thermal Expansion (NTE) elements configured as a core and connected to a drive mechanism; an immersion chamber adapted for housing the engine and adapted to be sequentially filled with fluid to allow a heating cycle and a cooling cycle of the SMA elements or NTE elements to expand and contract the SMA elements or NTE elements; and a compression device configured to apply a compressive mechanical force to at least one of the SMA elements or at least one of the NTE elements. The applied compressive mechanical force compresses the at least one SMA element or the at least one NTE element further during the cooling cycle.

A device for thermal energy harvesting can use pulsed heat.

An engine includes a thermal unit, a force introducing unit applying a force to a shaft of the thermal unit in a first direction, and/or a switch assembly that switches between a first state and a second state. In the first state, the switch assembly transfers thermal energy from a source to the thermal unit, which causes the shaft to move in a second direction from a first position to a second position. The switch assembly switches to the second state (i) during movement of the shaft in the second direction, (ii) when the shaft reaches the second position, and/or (iii) when the shaft reaches a third position between the first position and the second position. In the second state, the switch assembly transfers thermal energy from the thermal unit to outside the thermal unit, which causes the shaft of the thermal unit to move in the first direction.

Disclosed is an apparatus for generating electric energy from hot air dissipated by a system. The apparatus may comprise two chambers, a set of tubular arrangements, and an outlet port. The two chambers may comprise a first chamber and a second chamber. In one embodiment, the first chamber and the second chamber may comprise a first electrode and a second electrode respectively. The set of tubular arrangements may be mounted over the first electrode and the second electrode in a manner such that the hot air may be passed through a first end towards a second end of each tubular arrangement. The passing of the hot air may enable each tubular arrangement to contract in a manner such that second end of each tubular arrangement establishes a contact with the second electrode thereby completing an electric circuit to generate the electric energy.

The invention provides an energy recovery device comprising an engine comprising a plurality of Shape Memory Alloy (SMA) or Negative Thermal Expansion (NTE) elements fixed at a first end and connected at a second end to a drive mechanism wherein a holder is configured with a plurality of slots adapted to receive the plurality of Shape Memory Alloy (SMA) or NTE elements.

An energy cell that is provided with a pressure vessel with two chambers separated by a membrane, respectively a first chamber filled with a phase-change material and a second chamber filled with hydraulic fluid, whereby this energy cell is provided with means to be able to heat and cool the phase-change material alternately, coupled with a volume change, whereby the second chamber is provided with a passage that acts as an input and/or output for the hydraulic fluid, whereby the membrane is stretched elastically upon a phase change whereby the volume in the first chamber increases.

The present invention provides a waste-heat recovery and power generation system for liquid-cooled data centres and computing centres, to capture and use their waste heat and use it to produce electricity, allowing the data centres and computing centres to self-supply a part of their electrical needs in a cost-effective manner. The system uses heat collected from the electronic components to heat and vaporize a working fluid; uses the vaporized working fluid(s) to power an expander; uses the expander to drive an electric generator; uses a condenser to condense the partially cooled vapour expelled from the expander; uses a pump to return the condensed working fluid to the evaporator system; and uses a control system to manage the valves of the heat-capture system and the expander, and to manage the generation system order to maximize efficiency and power quality.

An SMA actuator assembly (1a) for driving or rotating a movable part (20) in a predetermined direction or sense by a plurality of repeated incremental steps is provided. The SMA actuator assembly comprises the movable part; a first engagement portion (31) for engaging the movable part; two SMA wires (41, 42) arranged to move the first engagement portion such that the first engagement portion repeatedly, for each of said incremental steps, is configured to do the following: engage with the movable part from a starting position, exert a force or torque on the movable part in the predetermined direction and disengage from the movable part and return to the starting position. The exertion of the force or torque on the movable part and the engaging or disengaging with the movable part are caused by contraction or relaxation of the two SMA wires.