Simulation of Thermoacoustic Oscillations in a Horizontall Rijke tube by CFD

Thermoacoustic oscillations occur in various equipments such as thermoacoustic engines, pulse combustors and industrial burners and result from a feedback loop between the heat transferred to the fluid from a heat source and acoustics of the geometry. If the heat input is at times of high pressure, a self-amplification of acoustic fluctuations may lead to high pressure amplitudes. The effect can be observed in a Rijke tube, a simple tube with a concentrated heat source (wire mesh) with both ends open in which air flows by a fan. The main objective of this paper is numerical simulation of horizontak Rijke tube and identify of thermoacoustic oscillations with computational fluid dynamics techniques (Fluent Software). The present modeling employs two-dimensional, compressible and unsteady flowfield coupled with heat addition that descritisize by using a control volume base finite difference method to solve iteratively the unsteady conservation equations for mass, momentum and energy. Also discusses the history, simplified and linear mathematical model of thermoacoustic oscillations in Rijke tube. The effects of system parameters such as heater location, energy required, etc. on the fluctuations are described using output graphs of software and validate with general behaviors of similar systems.

کلیدواژه ها:

Thermoacoustic oscillations ، Rijke tube ، Computational Fluid Dynamics