Direct numerical study of leading-edge contamination

摘要: Instability, turbulence, and relaminarization in the attachment-line region of swept unswept cylindrical bodies are studied by numerical solution full Navier-Stokes equations. The flow is simulated over a strip containing treated as homogeneous spanwise direction; disturbances decay exponentially upstream. Transpiration through wall may be prescribed. new method, which admits completely general disturbance, agrees with published linear-stability results, were limited to an apparently restrictive form disturbance. Fully developed turbulent solutions sweep generated compare well experiment. turbulence subcritical (except for blowing), resulting large hysteresis loops. By lowering Reynolds number, or increasing suction, made relaminarize. number much less sensitive suction than number. Extensive attempts detect postulated nonlinear instability failed, suggesting that this linearly nonlinearly stable.