On linear stability analyses of hypersonic laminar separated flows in a DSMC Framework Part II: Residuals algorithm and the least damped global modes

Linear global instability analysis of hypersonic laminar separated flows over a double cone and a 'tick' configuration is performed. Statistical analysis of unsteady DSMC data yields the average damping rates of the respective least damped perturbations. The residuals algorithm is then used to predict the converged steady state at a fraction of the DSMC computational effort, as well as identify the amplitude functions of the underlying global modes of shock-dominated laminar separated flow. It is seen that the main flow features, such as the shape and location of the shock, the triple point and the entire laminar separated region, are clearly reflected in the amplitude functions of the global modes. First steps are taken toward self-consistent instability analysis of DSMC-based hypersonic flows, based on linearization of the probability distribution function. The viability of the approach is demonstrated in incompressible global stability analysis computations based on the Lattice Boltzmann method.