Accurate simulation of the fuel-air mixing environment is crucial for high-fidelity scramjet calculations. We compute the velocity fields in cavity and jet into supersonic freestream flow configurations typical of scramjet flame-holding applications at different scale resolutions using the partially-averaged Navier-Stokes (PANS) method. We start with a brief description of the PANS methodology and closure model attributes. Then, we work our way up to scramjet simulations by presenting a sequence of careful verification and validation studies in relevant canonical flows such as those over cavity and backward-facing step. After establishing the physical fidelity of PANS, we proceed to simulate flame-holding flows and investigate their characteristic features at high Mach numbers. Copyright © 2009 by Sharath Girimaji.