Temperature Distribution in a Layer of Active Thermal Insulation System Heated by a Gas Burner

Temperature distribution in a layer of an active thermal insulation system was measured experimentally. A semitransparent porous layer was heated by a gas burner, and air was injected from the back face of the layer. The temperature in the layer was measured by thermocouples. The temperature distributions were compared with numerical solutions. The thermal penetration depth of the active thermal insulation layer with gas injection can be reduced to 3 mm. The surface temperature of a conventional insulation layer without gas injection reached 1 500 K, and the temperature at the back surface of a 10 mm thick layer reached 600 K. The transient temperature of the active thermal insulation reached a steady state very quickly compared with conventional insulation. These characteristics agreed qualitatively with numerical solutions.