Coupling IDDES with an algebraic transition model in a high-order discontinuous Galerkin solver

This work aims at designing a transitional hybrid RANS/LES on top of a high-order discretization framework. To do so, we employ the Improved Delayed Detached Eddy Simulation (IDDES) based on the Spalart-Allmaras closure and we equip it with an algebraic transition RANS branch, namely the SA-BCM model. In order to incorporate the transition model into the hybrid setup as seamlessly as possible we recalibrate one of the model coefficients and modify the IDDES shielding function to force the treatment of transitional regions in RANS mode. The numerical study makes use of an incompressible modal discontinuous Galerkin solver. The performance of the proposed implementation is evaluated by investigating a number of test cases, including the flow past aerodynamic profiles at various angle of attack and a sphere in supercritical conditions. The results are promising as the solver is able to accurately predict different transition mechanisms. Furthermore, they display the advantages associated with the proposed changes, some of which are not restricted to algebraic approaches, but can be extended to all transition models based on an intermittency function.