Comparisons of transition prediction using PSE-chem to measurements for a shock tunnel environment

Predictions from the STABL code have been used to make comparisons to two series of fundamental transition experiments in a large-scale shock tunnel environment by solving the parabolized stability equations (PSE) to predict laminar-turbulent transition onset using a semi-empirical e^N correlation. The two sets of experimental data were obtained at duplicated enthalpy Mach 10 conditions for slender geometries where transition is dominated by second-mode instability. The first experiment considered is a 7° cone with sharp and blunt nosetips where the surface pressure gradient is zero and the second is an axisymmetric compression surface with a significant adverse pressure gradient acting upon the flow. The PSE analysis has predicted N-factor growth between 5.2 and 8.6 at the measured transition station for these cases, demonstrating a range of instability conditions describing the physical phenomena. The use of the Ree/ME criterion is also explored, including examples on the axisymmetric compression surface where a low value indicating early transition shows the opposite trend to the more physically accurate PSE solution that indicates larger N-factor growth.