On the suitability of the immersed boundary method for the simulation of high-Reynolds-number separated turbulent flows

• We investigate the application of immersed boundary to high-Reynolds-number flows.
• Detached eddy simulation is applied for the first time with the IB method.
• We adopt model-consistent wall functions to provide appropriate boundary conditions.
• Several numerical tests are performed for massively separated flows.
• The accuracy of IB results is comparable to that obtained with body-fitted solvers.

Delayed detached eddy simulation based on the Spalart–Allmaras turbulence model is applied in conjunction with the immersed boundary method to high-Reynolds number turbulent flows in complex geometries. A fourth-order, finite-difference solver capable of discretely preserving the total kinetic energy in the limit of inviscid flow is adopted to solve the compressible Navier–Stokes equations and model-consistent, adaptive wall functions are employed to provide proper numerical boundary conditions at the fluid/solid interface. Numerical tests, performed for several configurations involving massively separated flows, demonstrate that computations at high Reynolds number typically occurring in flows of industrial relevance can be successfully carried out using the immersed boundary strategy, providing predictions whose accuracy is comparable to that of standard, body-fitted, structured and unstructured flow solvers.