Studies on the Transpiration Cooling : Surface Temperature Measurements on Transpiration Cooled Model in High Temperature Gas Stream

Abstract

The transpiration cooling is an effective method for cooling the porous body in high temperature stream by ejecting the coolant from the porous surface and covering the body by the cool boundary layer. Many experimental and theoretical works have been done in the world and clarified the effectiveness of this cooling method. But experiments concerned with the surface temperature gradients on the transpiration cooled body (pipe or flat plate) along the stream are rare and it seems that the measurements of surface temperature distributions on a transpiration cooled model (for instance circular cylinder or elliptic cylinder in cross flow) are not yet achieved. This report deals the experiments of measuring the transpiration cooled surface temprature on the model (porous circular and elliptic cylinder in cross flow) in high temperature streams and shows quantitatively the surface temperature distributions on the model and clarifies that this surface temperature gradients of the cooled surfaces were produced by the non-uniform ejection of coolant along the body surface caused by surface pressure gradients.