Synthesis of MSTIP calibration campaigns in ONERA F4 hot shot wind tunnel

The ONERA F4 Hot Shot wind tunnel provides hypersonic air flows at high enthalpy and high pressure total conditions. In such a hypersonic wind tunnel, real gas effects are large yielding experimental difficulties to assess either the free stream conditions in front of the model or the actual total enthalpy. In F4, the test condition knowledge was achieved mainly by indirect means, i.e. through the numerical rebuilding of experiments (classical and optical measurement results), concerning calibrations with rakes and standard models. The present paper described how topics of first importance for this type of wind tunnel were addressed i.e. the assessment of total enthalpy and of free stream uniformity and properties. A striking element of the conclusion is that, at high enthalpy, the free stream flow seems to be close to equilibrium.