A low-dissipation monotonicity-preserving scheme for turbulent flows in hydraulic turbines

[摘要] The objective of this work is to improve the inherent dissipation of the numerical schemes under the framework of a Reynolds-averaged Navier-Stokes (RANS) simulation. The governing equations are solved by the finite volume method with the k-ω SST turbulence model. Instead of the van Albada limiter, a novel eddy-preserving limiter is employed in the MUSCL reconstructions to minimize the dissipation of the vortex. The eddy-preserving procedure inactivates the van Albada limiter in the swirl plane and reduces the artificial dissipation to better preserve vortical flow structures. Steady and unsteady simulations of turbulent flows in a straight channel and a straight asymmetric diffuser are demonstrated. Profiles of velocity, Reynolds shear stress and turbulent kinetic energy are presented and compared against large eddy simulation (LES) and/or experimental data. Finally, comparisons are made to demonstrate the capability of the eddy-preserving limiter scheme.

[发布机构] McGill University, 817 Sherbrooke Street West, Montreal; QC; H3A 0C3, Canada^1

[关键词] Artificial dissipation;Governing equations;Reynolds shear stress;Reynolds-averaged navier-stokes simulations;SST turbulence models;Turbulent kinetic energy;Unsteady simulations;Vortical flow structures