The characteristics of a "Radiant Transfer Thermal Diode" in the form of a flat panel are examined. The thermal diode transfers heat radiantly instead of through mass transfer. It has no moving fluids or parts and can be operated in any position. The panel is constructed from mild steel with a honeycomb support system. Selective surfaces are utilized on both sides of the panel. Around the perimeter of the panel is a foam-filled stainless steel closeout. The panel is evacuated. Steady-state performance of the Radiant Transfer Thermal Diode is evaluated by means of a guarded hot box. The guarded hot box is used for vertical, horizontal, and incline testing purposes. The objectives of the project are: (1) construct a guarded hot box for the purpose of measuring the thermal performance of the Radiant Transfer Thermal Diode according to ASTM C236-80 specifications; (2) fabricate a I"x4'x8' flat Radiant Transfer Thermal Diode from mild steel with selective surfaces and a closeout of stainless steel which is then evacuated to 30 milli torr; and (3) measure the heat flux in both directions of the flat Radiant Transfer Thermal Diode under different temperature extremes and record data in usable tables.The potential commercial application as described by the awardee: Implications of the research are far-reaching with numerous domestic and industrial applications. Applications include: (1) heat control of space vehicles, (2) heat dissipation of industrial processes, and (3) heat control for passive solar systems in both residential and commercial building construction.
