Compressible Velocity Transformations for Various Noncanonical Wall-Bounded Turbulent Flows

Although several velocity transformations for compressible zero-pressure-gradient boundary layers have been proposed in the past decades, their performance noncanonical wall-bounded turbulent flows has not systematically investigated. This work assesses popular profile through application to types of flows. Specifically, this explores direct numerical simulation databases high-enthalpy with dissociation and vibrational excitation, supercritical channel boundary-layer flows, adiabatic pressure gradients. The considered include van Driest (“Turbulent Boundary Layer Compressible Fluids,” Journal Aeronautical Sciences, Vol. 18, No. 3, 1951, pp. 145–216), Zhang et al. (“Mach-Number-Invariant Mean-Velocity Profile Turbulent Layers,” Physical Review Letters, 109, 5, 2012, Paper 054502), Trettel Larsson (“Mean Velocity Scaling Wall Turbulence Heat Transfer,” Physics Fluids, 28, 2, 2016, 026102), data-driven (Volpiani al., “Data-Driven Compressibility Transformation 2020, 052602), total-stress-based (Griffin “Velocity Wall-Bounded Flows Without Proceedings National Academy Sciences United States America, 118, 34, 2021, e2111144118) transformations. Trettel–Larsson transformation collapses profiles temporal but spatial considered. For also performs well over entire inner layer. None aforementioned layers. all methods, transformed weak gradients coincide universal incompressible law wall. In summary, these methods fail deliver uniform logarithmic region, a more sophisticated version, which accounts different physics, is needed. perform viscous sublayer Nevertheless, present assessment provides useful guideline on deployment various