Investigation of Phase-Lagged Boundary Conditions for Turbulence Resolving Turbomachinery Simulations

Paper in proceeding, 2020

The present work explores whether phase-lagged boundary conditions can be used to perform scale resolving simulations of turbomachines. The phase-lagged approach considered is based on storing the flow signal, both at the pitch-wise boundaries and the rotor-stator interface, as its temporal Fourier coefficients for a finite number of harmonics. The method is implemented in an in-house CFD solver, G3D::Flow, which can perform both URANS and hybrid RANS/LES simulations. In order to evaluate the performance of the phase-lagged boundary condition, a comparison is made with a sliding mesh simulation on a compressor cascade. Furthermore, the possibility of breaking an error feedback loop generated in the sampling process by including multiple blade passages is also investigated. It is found that this approach greatly improves convergence and accuracy of the sampling.