EXPERIMENTAL-STUDY OF TRANSPIRATION GAS-C OOLING THROUGH A POROUS WALL

A heated air tunnel and specially its test section features, designed for studies of wall protection from high temperature gases, are descri bed. A coolant, moving through the porous wall, flush fitted in the ho rizontal test section floor, achieves its thermal protection. Prelimin ary velocity measurements, carried out at ambient temperature and with out injection, within the test section, pointed out the following aero dynamic characteristics: stationarity and turbulence intensity in the potential flow, boundary layer Features over the porous wall according to the entrance test section boundary conditions, wall friction coeff icient estimation. Velocity and temperature profiles, in non-isotherma l conditions, over the porous wall with or without cooling air injecti on, are reported. They point out the injection rate influence, variabl e from 0 to 2 %. (C) Elsevier, Paris.