Efficient Large Eddy Simulation of a Low-Mach Number Axial Fan

C2 - Numerical Methods

A weakly-compressible formulation for Large Eddy Simulation (LES) is shown to be a suitable tool for simulation of fan flow as a part of a fan noise prediction effort. LES can directly capture the inertial-range turbulence that produces the broadband component of the noise. In the present formulation, the density and pressure are coupled in each time step through an isentropic relationship. When solved using a fractional-step method, this density-pressure coupling leads to a Helmholtz system for pressure that implicitly captures the acoustics without introducing additional numerical stiffness. The method is applied to an experimental configuration and shows good agreement with both integral parameters and flow velocity statistics.