Heat transfer effects in compressible turbulent boundary layers with and without pressure gradients

Abstract: Recent advances in theory and high-fidelity simulation have expanded our understanding of compressible turbulent boundary layers, enabling the investigation of increasingly complex high-speed flow configurations. This presentation discusses recent work on compressible turbulent boundary layers with heat transfer and their interactions with pressure gradients.

The first part presents a classification scheme based on a comprehensive set of direct numerical simulations of diabatic flat-plate boundary layers. Super- and hypersonic cases are classified by the wall-normal temperature peak into heated, adiabatic, and multiple cooling regimes, with explicit relationships to parameters such as the Mach number, wall-to-recovery temperature ratio, and Eckert number. This framework enables a priori estimation of heat-transfer effects and maintains accuracy for high-enthalpy flows with added thermochemical complexity.

The second part examines the combined influence of pressure gradients and wall heat transfer in supersonic boundary layers. The design of simulations of approximately self-similar flows is outlined. The resulting pressure-gradient and thermal effects are described. The findings show that existing similarity frameworks capture the dominant behavior under these conditions and enable an assessment of the Strong Reynolds analogy in the presence of self-similar pressure gradients.

Bio: Tobias Gibis is a new Postdoctoral Fellow at the Center for Turbulence Research (CTR) at Stanford University. He received his PhD from the University of Stuttgart. His research focuses on high-fidelity numerical simulations of compressible turbulent boundary layers, emphasizing the interaction between heat transfer and pressure gradients.