Accounting for convective effects in zero-Mach-number thermoacoustic models |
| |
Authors: | E Motheau L Selle F Nicoud |
| |
Institution: | 1. CERFACS - CFD Team, 42 av. Gaspard Coriolis, 31057 Toulouse, France;2. Université de Toulouse, INPT, UPS, IMFT (Institut de Mécanique des Fluides de Toulouse), Allée Camille Soula, F-31400 Toulouse, France;3. CNRS, IMFT, F-31400 Toulouse, France;4. CNRS UMR 5149 - University Montpellier II, 34095 Montpellier, France |
| |
Abstract: | This paper presents a methodology to account for some mean-flow effects on thermoacoustic instabilities when using the zero-Mach-number assumption. It is shown that when a computational domain is represented under the M=0 assumption, a nonzero-Mach-number element can simply be taken into account by imposing a proper acoustic impedance at the boundaries so as to mimic the mean flow effects in the outer, not computed flow domain. A model that accounts for the coupling between acoustic and entropy waves is presented. It relies on a “delayed entropy coupled boundary condition” (DECBC) for the Helmholtz equation satisfied by the acoustic pressure. The model proves able to capture low-frequency entropic modes even without mean-flow terms in the fluctuating-pressure equation. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|