Energy amplification of stochastically-forced hypersonic blunt body flows

We utilize stochastically-forced compressible linearized Navier-Stokes equations to study the dynamics of hypersonic flows over blunt bodies. Our analysis of the energy of the flow fluctuations around the laminar stagnated flow reveals strong amplification of specific streamwise and spanwise length scales. We also provide insights into how changes in different physical parameters, such as the temperature of the blunt body and its curvature, influence the amplification of flow fluctuations. We show that increasing the bluntness and decreasing the wall temperature can significantly enhance the amplification of flow fluctuations. Our approach offers a systematic control-theoretic framework for quantifying the influence of stochastic excitation sources (e.g., free-stream turbulence and surface roughness) that are unavoidable in experiments and paves the way for the development of control-oriented models of hypersonic flows over blunt bodies.