Particle-impingement simulations for a hypersonic flow over a blunt cone

The laminar to turbulent transition process in hypersonic boundary layer flows is strongly affected by external parameters, such as the freestream environment. The transition process significantly affects heat transfer rates and understanding this process is vital for the design of hypersonic vehicles. This research focuses on the first stage of many in the highly-complex multi-stage transition process, namely the receptivity stage. Recent studies have shown that for sufficiently large particles and a high enough particle concentration particle-induced transition may provide a viable path to turbulence. While prior research on particle induced transition was mainly concerned with the excitation of modal disturbances inside the boundary layer this work investigates if particles can induce non-modal growth. The geometry and flow conditions were chosen in accordance to the work by Paredes et al.,³⁵ who observed non-modal growth for the chosen setup. Direct numerical simulations were performed with an established adaptive mesh refinement wave-packet tracking simulation approach which allows to efficiently track the disturbance flow field. The flow structures generated by the particle impingement show close similarities to those which have been observed in prior theoretical work.