Transition in High-Speed Boundary Layers: Numerical Investigations Using DNS and LES
Abstract
Direct Numerical Simulations (DNS) of supersonic flow over a flat-plate with and without adverse pressure-gradient at Mach 3 were carried out in close collaboration with the experimental effort at Princeton University by G. Brown and co-workers. To confirm that simulations and experiments were based on the same "baseflow," the experimental baseflow profiles were compared with our Navier-Stokes results. The downstream development and the spatial growth rates of the disturbances obtained from the Navier-Stokes computations and from experimental measurements were compared as well. Overall, a remarkably good agreement was achieved. Towards the understanding of the nonlinear mechanisms, we investigated numerous nonlinear resonance and breakdown scenarios. Our simulations have shown that due to the stabilizing effects of compressibility for supersonic boundary layers, the transition process can be stretched significantly in the downstream direction and sometimes the transition process may even be aborted so that a turbulent boundary layer is never fully established. The extent of the transition process and the intensity of the temperature fluctuations, and the resulting heat load, depend strongly on the nonlinear mechanisms.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 22, 2005
- Accession Number
- ADA430590
Entities
People
- Hermann F. Fasel
Organizations
- University of Arizona