Integration of rans and les flow solvers for simultaneous flow computations

Numerical investigations of highly complex flow systems, such as the aero-thermal flow through an entire aircraft gas turbine engine, require the application of multiple specialized flow solvers in order to compute the flow efficiently and accurately. The flow solvers have to run simultaneously in order to capture unsteady multi-component effects. The present study reports the coupling of two flow solvers, one based on a RANS approach, the other on a LES approach. Procedures to set up an efficient data exchange are described. The processing of the flow data to meaningful boundary conditions is discussed. As a validation case for integrated RANS/LES computations, a swirl flow at an expansion with a subsequent contraction is computed and compared to LES results of the entire domain.