Different injection geometries (one jet, one row of jets and two injection rows) are tested here. The injection flow goes through a heated wall into a turbulent boundary layer of ambient air. The injection rate varies between 0.3 and 2.2; the injection temperature varies from the ambient to 65 degrees C. The temperature of the wall is measured by infrared thermography. This paper presents a model of the wall heal transfer by using two coefficients of heat transfer. One translates the influence of the mainflow on the plate, the other the influence of the injection flow.