EVALUATION OF CFD TRANSITION MODELING FOR TRANSONIC, NATURAL-LAMINAR-FLOW DESIGN

A critical evaluation of prominent PDE-based laminar-turbulent transition models for CFD applications is presented. Several variants of the Amplification Factor Transport (AFT) modeling framework, along with a LocalCorrelation Transition Model, are assessed. As the baseline models are anchored to incompressible considerations, candidate compressibility corrections are presented for the AFT models. A crossflow transition extension is included with all the models; however, this is de-emphasized in favor of streamwise mechanisms in the present study. The models are applied to test cases of varying complexity to test their accuracy for capturing the movement of transition with changing angle of attack and their sensitivity to varying Mach numbers in the near-sonic regime, both of which are crucial details for using such transition models for natural-laminar-flow design in the transonic regime. It is ultimately found that the AFT2014 model with a compressibility correction performs best, providing accurate solutions and exhibiting the desired behavior in the presence of changing lift and changing Mach number.