Development and Validation of a Massively Parallel Flow Solver for Turbomachinery Flows

The development and validation of the unsteady, three-dimensional, multiblock, parallel turbomachinery  ow solver TFLO is presented. The unsteady Reynolds-averaged Navier–Stokes equations are solved using a cellcentered discretizationon arbitrarymultiblockmeshes. The solutionprocedure is basedon efŽ cient explicit Runge– Kuttamethodswith several convergenceacceleration techniques such asmultigrid, implicit residual smoothing, and local time stepping. The solver is parallelized using domain decomposition, a single programmultiple data strategy, and the message passing interface standard. Details of the communication scheme and load balancing algorithms are discussed. A general and efŽ cient procedure for parallel interblade row interfacing is developed. The dual-time stepping technique is used to advance unsteady computations in time. The focus is on improving the parallel efŽ ciency and scalability of the  ow solver, as well as on its initial validation of steady-state calculations in multiblade row environment. The result of this careful implementation is a solverwith demonstrated scalability up to 1024 processors. For validation and veriŽ cation purposes, results fromTFLO are comparedwith both existing experimental data and computational results from other computational  uid dynamics codes used in aircraft engine industry.