Prediction of Incompressible Separated Boundary Layers Including Viscous-Inviscid Interaction

Abstract

A viscous-inviscid interaction calculation procedure is described for viscous flows containing separation bubbles based on an inverse finite-difference boundary layer method and a small disturbance Cauchy integral formulation for the inviscid flow. The viscous-inviscid matching procedure used appears to eliminate the need for smoothing or under-relaxation which is commonly required by other methods. Turbulence modeling for transitional separation bubbles is discussed and two empirically-based transition models are evaluated for bubble flows. Predictions for a laminar and a laminar-turbulent transitional bubble are presented. These predictions are compared with results from other prediction methods and with experimental measurements for the transitional bubble flow.