RÉSUMÉ

Direct numerical simulation (DNS) is carried out to study the compressible flow over a fully three-dimensional open cavity, which has a length-to-depth ratio L/D = 5 and width-to-depth ratio W/D = 1. The Mach number of the incoming flow is M = 0.85, and the Reynolds number based on the cavity depth is Re_D = 5000. The unsteady flow dynamics is analyzed, focusing on the cross-stream flow patterns, unlike previous studies. The implication for sound generation in the cross-stream direction is discussed. The DNS database contains Reynolds averaged quantities as well as instantaneous ones, making it valuable for model development and validation.