Planar Thermic Elements for Thermal Control Systems

Thermics is a newly emerging control discipline where heat flows are modulated by temperatures. Heat is the only energy medium necessary for control, analogous to other single-medium control disciplines such as electronics, hydraulies, pneumatics or fluidics. Although initially dominated by elements based on vaporization heat tranfser of the heat pipe, a new class of planar thermic logic and control elements has been invented that relies on conduction and convection heat transfer. Three different temperature modulated thermal resistors are presented to explore the various types of modulation possible. The convection type is shown in several variations (amplifier, NOR gate, and diode) to illustrate analog, digital, and nonlinear control elements. Bond Graph models and experimental data are presented on characteristics of these prototype devices.