Provided is a thermoacoustic refrigerator including an air column pipe, a prime mover, a load, and a heat accumulation tank. An exhaust gas supplied to and discharged from the heat accumulation tank is supplied, as a heat source, to the prime mover disposed inside the air column pipe, so as to cause self-oscillation of a working gas filled in the air column pipe so that sound waves are generated. With the sound waves, the load disposed inside the air column pipe converts sound wave energy into heat energy, so as to output cold heat.

A thermoacoustic device includes a process volume which is filled with a working fluid through which the acoustic wave propagates. The thermoacoustic device further includes an acoustic network comprising a tubular loop configured with a passage providing an opening in the loop and configured as acoustic circuit provided with a compliance volume, a thermo-acoustic core and an inertance volume. Within the loop, the thermoacoustic core is at a first side thereof adjacent to the passage at a first path length through the loop, and at its second side, opposite to the first side, the thermoacoustic core is at a second path length from the passage. The thermoacoustic device includes within the loop a spring-type partitioning element that is configured to close off the cross-section of the tube and to be impermeable for the working fluid while allowing transmission of pressure waves in the working fluid through the spring-type partitioning element.

A heat/acoustic wave conversion component includes a plurality of monolithic honeycomb segments each including a partition wall that defines a plurality of cells extending between both end faces, and the plurality of monolithic honeycomb segments each mutually converts heat exchanged between the partition wall and the working fluid in the cells and energy of acoustic waves resulting from oscillations of the working fluid. In the heat/acoustic wave conversion component including the plurality of honeycomb segments each being monolithic configured, hydraulic diameter HD of the cells is 0.4 mm or less, open frontal area of the honeycomb segments is 60% or more and 93% or less, heat conductivity of the honeycomb segments is 5 W/mK or less, and a ratio HD/L of the hydraulic diameter HD to the length L of the honeycomb segment is 0.005 or more and less than 0.02.

A heat/acoustic wave conversion unit includes a heat/acoustic wave conversion component and two heat exchangers. Hydraulic diameter HD of the cells in the heat/acoustic wave conversion component is 0.4 mm or less, and a ratio HD/L of HD to the length L of the heat/acoustic wave conversion component is from 0.005 to 0.02. One of the heat exchangers includes a heat-exchanging honeycomb structure and an annular tube that surrounds a circumferential face of the heat-exchanging honeycomb structure. The annular tube includes a structure body that is disposed in the channel to increase a contact area with the heated fluid, an inflow port into which the heated fluid flows, and an outflow port through which the heated fluid flows out. At least one of the heat-exchanging honeycomb structure and the structure body is made of a ceramic material that contains SiC as a main component.

A heat/acoustic wave conversion component includes a partition wall that defines a plurality of cells, inside of the cells being filled with fluid that oscillates to transmit acoustic waves, the heat/acoustic wave conversion component mutually converting heat exchanged between the partition wall and the fluid and energy of acoustic waves resulting from oscillations of the fluid. The plurality of cells have an average of hydraulic diameters HDs that is 0.4 mm or less in a plane perpendicular to the cell extending direction, the heat/acoustic wave conversion component has an open frontal area at each end face of 60% or more and 93% or less, and distribution of hydraulic diameters HDs of the plurality of cells has relative standard deviation that is 2% or more and 30% or less.

Provided is a thermoacoustic refrigerator including an air column pipe, a prime mover, a load, and a heat accumulation tank. An exhaust gas supplied to and discharged from the heat accumulation tank is supplied, as a heat source, to the prime mover disposed inside the air column pipe, so as to cause self-oscillation of a working gas filled in the air column pipe so that sound waves are generated. With the sound waves, the load disposed inside the air column pipe converts sound wave energy into heat energy, so as to output cold heat.

A thermoacoustic device includes a stage coupled to a bar, wherein the stage includes a first heating component on a first terminus of the stage. The stage further includes a first cooling component on a second terminus of the stage. A thermal conductivity of the stage is higher than a thermal conductivity of the bar. A heat capacity of the stage is higher than a heat capacity of the bar.

A thermal management system for an aircraft is provided that includes thermo-acoustic engines that remove and capture waste heat from the aircraft engines, heat pumps powered by the acoustic waves generated from the waste heat that remove and capture electrical component waste heat from electrical components in the aircraft, and hollow tubes disposed in the aircraft configured to propagate mechanical energy to locations throughout the aircraft and to transfer the electrical component waste heat back to the aircraft engines to reduce overall aircraft mass and improve propulsive efficiency.

An electric propulsion system of an aircraft includes an electrical generator and a cooling device of the electrical generator. It further includes at least one thermoacoustic engine and a heat transfer circuit configured to transport heat dissipated by the electrical generator to the thermoacoustic engine. The cooling device of the electrical generator is at least partially powered by energy from the thermoacoustic engine.

A thermoacoustic device includes a loop tube in which a working gas is sealed; a stack in which a temperature gradient is generated in a tube axis direction of the loop tube, the stack being provided in the loop tube; and a diaphragm structure including a diaphragm provided in the loop tube and an operation unit, the diaphragm having a surface extending in a direction intersecting the tube axis direction and being configured to vibrate with a component of vibration in the tube axis direction, and the operation unit being configured to apply a physical quantity that is required, to the diaphragm to change a rigidity of the diaphragm in the tube axis direction.