A Laser Generated Thermal Spot Model for Accurate CFD Receptivity Simulations

A model of a laser generated thermal spot useful as a controlled, repeatable perturbation for high speed receptivity experiments has been developed with model parameters adjusted to match earlier receptivity experiments. Accurate CFD simulations of these same receptivity experiments have been performed by others, but with inadequately modeled perturbations for their input. Since CFD simulations of the previous benchmark receptivity experiments are useful for code validation, an accurate model of the input perturbation is essential. The presented perturbation model generates a detailed density profile and time evolution of the perturbation, comprised of a core thermal spot and surrounding weak shock, as well as its motion downstream. In addition, optical path dierences are computed as simulated laser dierential interferometer output, and results are in excellent agreement with the previous receptivity experiments. Separately, a method of comparison with more accurate CFD simulations of the same receptivity experiments is presented with results to illustrate why the new perturbation model might be useful.