Prediction of drag crisis on a circular cylinder using a new algebraic transition model coupled with SST DDES

Flows with massive separation zones are frequent in industrial applications and pose a considerable challenge for contemporary turbulence solving techniques. Accurate prediction of these types of flows can be broken down into two distinct problems: prediction of separation points, which can be addressed by using laminar to turbulent transition models in RANS framework and description of the separated regions, best dealt with by using LES. The present work proposes a new algebraic transition model which is then coupled with the hybrid RANS-LES method DDES with the resulting approach tested on a flow around a circular cylinder on a wide range of Reynolds numbers ranging from sub- to super-critical. Results show that the proposed method is an improvement relative to both RANS and DDES methods and shows promise but requires further development.