Numerical simulation of a compressible shear layer
Abstract
The nonlinear development of two-dimensional supersonic instability waves in a mixing layer is investigated by solving the full unsteady Navier-Stokes equations. A finite difference predictor-corrector explicit method is used. The method is second-order accurate in time and fourth-order accurate in space. Both confined and unconfined shear layers are simulated. For a fast or a slow mode of instability, in which the flow relative to the wave is subsonic on one side and supersonic on the other side, rolled-up vortical structures are observed on the subsonic side. The development of these structures is enhanced by confining the layer between parallel walls. Oblique shock waves develop in the supersonic side. In the unconfined case, the shock waves form in the far field as a result of the coalescence of compression waves initiated at the shear layer. In the confined shear layer case, they appear as reflections of compression waves off the side wall. In the case of supersonic relative Mach numbers on both sides of the layer, no vortical roll up is observed; only a staggered pattern of oblique shock waves is found.
- Publication:
-
AIAA, Fluid Dynamics, 21st Plasma Dynamics and Lasers Conference, 21st, Seattle, WA, June 18-20, 1990. 17 p.
- Pub Date:
- June 1990
- Bibcode:
- 1990fdpd.confY....R
- Keywords:
-
- Compressible Fluids;
- Computational Fluid Dynamics;
- Finite Difference Theory;
- Mixing Layers (Fluids);
- Predictor-Corrector Methods;
- Shear Layers;
- Unsteady Flow;
- Far Fields;
- Flow Stability;
- Oblique Shock Waves;
- Subsonic Flow;
- Supersonic Flow;
- Vortices;
- Fluid Mechanics and Heat Transfer