Energy transfer in shock wave/turbulent boundary layer interactions

The energy transport and exchange processes among the mean kinetic energy (MKE), turbulent kinetic energy (TKE), mean internal energy and turbulent internal energy in a shock wave/turbulent boundary layer interaction (SBLI) are quantified using direct numerical simulations. By analyzing the transport budgets of mean and fluctuating energy modes, the primary mechanisms governing energy transfer cycles within the interaction region are identified. Results show that energy transfer is dominated by three key processes: turbulence production ( Pₖ P k ), which transfers energy from the mean flow to turbulence, mean pressure dilatation ( Φᵖᵐ Φ pm ), which mediates the compressibility-driven energy exchange between MKE and mean internal energy, and viscous dissipation ( ε ε ), which irreversibly converts TKE into mean internal energy. The effects of variable density and terms related to turbulent internal energy are found to be negligible. The present work clarifies the essential energy transfer pathways in SBLI, offering valuable insights for the development of improved turbulence closure models and the design of effective flow control strategies.