Transpiration Cooling. Part I. Analytical Model.

An analytical method is presented for investigation of transpiration cooling and the downstream cooling effects beyond the point of discontinuous blowing. The method presented is restricted to the laminar regime. An integral method which satisfies the first two compatibility conditions at the wall is developed for both the velocity and thermal boundary layers. An exponential function is incorporated for both the velocity and temperature fields. The boundary layer definition is extended through the position of discontinuous blowing to the point of separation. The wall temperature is assumed constant in the transpiration regime and is allowed to vary downstream from the permeable wall to evaluate the effects of downstream cooling. Asymptotic expressions are given for both large blowing and suction velocities. Author Modified Abstract