Thermal control systems that include variable conductivity metamaterial units are provided. The metamaterial unit a plurality of thermally conductive plates, a plurality of first bonds, each of which connects two adjoining thermally conductive plates, and a plurality of second bonds, each of which connects two adjoining thermally conductive plates. Also included is a load inducer constructed to cause the plurality of thermally conductive plates to move between a non-contact state, in which opposing surfaces of the plurality of thermally conductive plates are not in direct contact, to a contact state, in which the opposing surfaces of the plurality of thermally conductive are in at least partial direct contact, so as to change a thermal conductivity of the metamaterial unit from a first value to a second value. Through the ability to design the effective thermal conductivity as a function of temperature a passive thermal control capability is achieved by the introduction of thermal stability regions that will passively ensure thermal stability.

Systems and methods are disclosed herein for passively managing cooling air in a gas turbine engine. A cooling air supply line may supply cooling air to a component in the gas turbine engine. A metering coupon may have a negative coefficient of thermal expansion. The metering coupon may allow more airflow through the metering coupon and through the component in response to an increase in temperature.

A fluid flow control device controls flow of coolant in a motor vehicle motor cooling system. The flow control device includes first and second coolant inlets and first and second coolant outlets. The flow control device is operable selectively to direct coolant flowing into the device to flow out from the flow device through one or both of the first and second outlets in dependence on a temperature of fluid flowing through the device.

A wax motor thermostat for an engine cooling system. The thermostat includes a cylinder having at least a first wax portion and a second wax portion each configured to expand at different temperatures. A piston is movable in response to expansion of the first and second wax portions to move the wax motor thermostat from a closed position to a fully open position or a partially open position between the closed and fully open positions to allow coolant to flow through the wax motor thermostat.

A hydraulic control system includes a primary sump and an auxiliary sump. When the transmission fluid is warm, fluid remains in the auxiliary sump reducing the volume of oil in circulation throughout the transmission to reduce parasitic losses. An oil control valve is designed to block flow of oil from the auxiliary sump to the primary sump when the fluid is warm and to allow flow when the fluid is cold. The oil control valve also responds to transmission line pressure. At moderate temperatures, fluid is held in the auxiliary sump when the engine is running but drains back to the primary sump when the engine is off.

The thermal actuator can have a housing, a moving member, a sensing portion configured to move the moving member relative the housing when receiving heat from a source of heat, and a thermal insulator between the sensing portion and the source of heat.

Thermal control systems that include variable conductivity metamaterial units are provided. The metamaterial unit a plurality of thermally conductive plates, a plurality of first bonds, each of which connects two adjoining thermally conductive plates, and a plurality of second bonds, each of which connects two adjoining thermally conductive plates. Also included is a load inducer constructed to cause the plurality of thermally conductive plates to move between a non-contact state, in which opposing surfaces of the plurality of thermally conductive plates are not in direct contact, to a contact state, in which the opposing surfaces of the plurality of thermally conductive are in at least partial direct contact, so as to change a thermal conductivity of the metamaterial unit from a first value to a second value. Through the ability to design the effective thermal conductivity as a function of temperature a passive thermal control capability is achieved by the introduction of thermal stability regions that will passively ensure thermal stability.

A thermostat comprises a hollow body containing a thermally responsive material, and a force transmitting member affixed to the body by an over-molded portion.

The temperature switch includes a housing, an actuator, a switch, and a force buffer situated between the actuator and the switch. The switch is movable between a first and second state in response to imposition and release of an actuating force F.sub.A. The force buffer transmits the actuating force F.sub.A from the actuator to the switch when compressed a first distance in the first direction by extension of the actuator in response to an increase in temperature T.sub.1. At temperature T.sub.1, the force buffer transmits the force F.sub.A to move the switch from the first state to the second state. The actuator retracts a second distance in the second direction in response to a decrease in temperature T.sub.2. At temperature T.sub.2, the force buffer releases the force F.sub.A and the switch moves from the second state to the first state.

Standalone and self-contained cooling systems using compressed liquid and/or gas CO.sub.2 containers positioned in an insulated or non-insulated vessel and consisting of a specially designed unit where the containers are vertically positioned in an upright or upside-down position. The liquid and/or gas CO.sub.2 coolant is then released into capillary tube(s) embedded into a heat transfer plate or heat exchanger thus leveraging the CO.sub.2 coolant properties. The temperature is controlled by a metering CO.sub.2 releasing system encompassing an electronic control device which can be operated remotely and/or via a touch screen and which sends alerts when pre-defined thresholds are exceeded. The invention's metering CO.sub.2 releasing system may be triggered by an electronic or a thermostatic valve or may be triggered manually or by an electronic solenoid. The invention's cooling system also encompasses check valves, which avoid liquid and/or gas CO.sub.2 from escaping when removing or replacing CO.sub.2 containers individually.