Assessment of an Intermittency Based Approach to Separated Flow Transition Predictions in Low-Reynolds Number High-Lift Cascade Flow

An intermittency based approach for separated flow transition coupled with a two equation turbulence model has been used to predict low-Reynolds number high-lift cascade flows. The intermittency function is based on the vorticity Reynolds number and on a critical Reynolds number for separated flow transition onset. The intermittency function is allowed to exceed the unity in laminar separation bubbles to enhance turbulence production thus permitting the flow reattachment. The proposed model can be "hosted" by any general intermittency formulation for attached flow, and can be used in conjunction to any turbulence closure. The proposed intermittency formulation has been tested on different cascade configurations in low-Reynolds number conditions. The comparison between computed and experimental results, in terms of blade surface Mach number distributions and losses will be presented and discussed for several Reynolds number values.