An annular design heat exchanger is formed from an arrangement of wedge-shaped stacks of wafers. Each wafer includes sheets of material separated by peripheral and supporting walls that define interior flow channels through which a first fluid can flow. Holes in the sheets provide inlets and outlets to the channels, and walls surrounding the holes mate with neighboring wafers in the stack, forming integral inlet and outlet manifolds, while ensuring uniform spacing between the wafers. A second fluid can flow around the manifolds and through the spaces between the wafers in a counterflow pattern. In the annular assembly, the manifolds are oriented substantially axially, and the flow channels are oriented substantially radially. The heat exchanger can be formed from a ceramic material, and can be incorporated into an engine assembly or a heat-recirculating combustor.

A heat dissipation system that includes a structure having a surface with a cavity recessed on the surface. A wing or channel causes a vortex to occur in the cavity. Destabilizers, such as projections or recesses are disposed on the sidewall of the cavity to disrupt the local surface boundary layer that forms in the cavity. Alternatively, a plurality of freely moving bead elements are disposed in the cavity to disrupt the local surface boundary layer. A cover can be included that prevents the bead elements from exiting the cavity.

A capillary flow valve for use in a two phase heat transfer system such as a loop heat pipe, including an inlet port for receiving working fluid in a vapor-phase, an outlet port for outputting working fluid in a vapor-phase, and a porous wick material extending across the interior of the valve. Heating the wick evaporates liquid-phase working fluid from the wick and allows the vapor-phase working fluid to pass through the wick to the outlet port. Removing the heat allows liquid to condense in the wick, preventing flow of the vapor-phase working fluid through the wick to the outlet port.

This invention pertains to apparatus and method for initiating detonation in a chamber of tubular or other shapes, which can be a combustor for a propulsion engine, such as a pulse detonation engine. This invention is characterized by detonation initiation at high pressure and temperature that is generated by imploding shocks induced by jets in different directions around the chamber. Further, the detonation initiation is achieved without energy depositing devices, such as electric spark plugs and lasers and without any fuel or other chemical additives.

A heat dissipation system that includes a structure having a surface with a cavity recessed on the surface. A wing or channel causes a vortex to occur in the cavity. Destabilizers, such as projections or recesses are disposed on the sidewall of the cavity to disrupt the local surface boundary layer that forms in the cavity. Alternatively, a plurality of freely moving bead elements are disposed in the cavity to disrupt the local surface boundary layer. A cover can be included that prevents the bead elements from exiting the cavity.

A personal portable environmental control system, which includes a thermoelectric device, two heat sinks, an exhaust fan for blowing ambient air across one heat sink and a blower for blowing ambient air across the other heat sink such that the blown air is conditioned (either heated or cooled). The thermoelectric device is disposed between the two heat sinks.

An air conditioning system that includes desiccant compartments for holding a desiccant; a heat exchanger, a blower and a vessel. The heat exchanger can be filled with a heat transfer medium, while the blower blows ambient air by the heat exchanger such that the blown air is cooled and the heat exchanger is warmed such that thermal energy increases and is transferred from the air to the heat transfer medium causing the heat transfer medium to turn into vapor. The vapor is then diffused to one of the desiccant compartments such that the vapor is adsorbed onto the desiccant creating a mixture. Then an energy source is applied to the mixture such that the vapor and desiccant are separated. The separated vapor is transported to the vessel where it is condensed and then sent back to the heat exchanger, such that the system is able to be continuously operating.