An Absorbing Inlet Buffer Layer for Rotor Wake/Stator Time Domain Computations

Paper in proceeding, 2009

This paper presents a method that concerns how absorbing buffer layers can be used at the inlet of nonlinear rotor wake/stator computations using an URANS solver with chorochronic, time lag, periodic boundaries in order to avoid spurious reflections of acoustic waves. If a part of the inlet to the stator domain rotates with the wake at the same speed as the rotor, the wake is stationary in this rotating inlet zone, and a standard buffer layer method can be used in the rotating frame of reference without destroying the wake. The rotating inlet buffer layer should have the same periodicity as the rotor and a chorochronic, Fourier-based in time and tangential direction, blade row interface can then be used between the rotating domain and the stator domain. This new method, using a rotating inlet buffer layer, is compared to other absorbing inlet boundary conditions, for example the 1D type (axial characteristics) or 2D type (axial-tangential characteristics), for a realistic high bypass ratio stator vane geometry, considering tone noise generation from the impingement of rotor wakes on the stators. Copyright © 2009 by ASME.