Hybrid Computational Fluid Dynamics/Thermoacoustic-Solver Approach to Model Acoustics in Combustion Simulations

摘要

In industrial problems such as combustion instabilities in gas-turbine engines and rockets, noise from piston engines, and cooling by thermoacoustic refrigerators, there is a complex interaction between acoustics and thermohydrodynamic processes. Ideally, one would represent this interaction by resolving as much physics as computer power allows, but this is expensive. On the other hand，the common practice of finding empirical boundary conditions takes extensive calibration. The present work is an attempt to enhance this state of affairs by proposing to model a portion of the duct system of interest with computational fluid dynamic techniques and the rest with three-dimensional linearized conservation laws solved with what is called here a thermoacoustic solver. The modeling error of this hybrid approach is presented for five different tests, including two combustion-instability problems. Furthermore, ways to improve it are discussed.