4. Verification of Transition Prediction for Flows with Suction Using Linear Stability Theory and \(e^N\)-Method

A transition prediction approach using linear stability theory and \(e^N\)-method is used for the evaluation of the stability of flows with suction. The input data for the stability analysis are directly taken from the solution of a RANS computation, where the suction velocity at the surface is introduced by a mass flux boundary condition. The prediction capability of the \(e^N\)-method is validated using different two– and three–dimensional experimental test cases, such as the flow over a NACA 64\(_2\)-A-215 and a NACA 64-A-010 airfoil and the flow over swept wings with ONERA D and ONERA DTP-B airfoil sections normal to the leading edge. A reduced critical N-factor for flows with suction, compared to a critical N-factor for the unaffected flow, is intended to account for disturbances possibly introduced to the flow due to the suction process itself or due to the surface roughness.