Influence of non perfect impedance boundary on the bistable region in thermoacoustic interactions

15th Asian Congress of Fluid Mechanics

物理学;力学

Mohan, B.^1 ; Mariappan, S.^1

Department of Aerospace Engineering, Indian Institute of Technology Kanpur, Kanpur

208016, India^1

关键词: Bifurcation parameter;    Bistable zones;    Frequency dependent impedance;    Impedance boundary;    Impedance boundary conditions;    Nonlinear dispersion relation;    Quantitative changes;    Stability boundaries;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/822/1/012006/pdf
DOI  :  10.1088/1742-6596/822/1/012006

学科分类：力学，机械学

来源: IOP

【 摘 要 】

We investigate the influence of non perfect impedance boundary on the bistable zone in thermoacoustic interactions of a horizontal Rijke tube. A wave based approach is used to obtain the nonlinear dispersion relation with frequency dependent impedance boundary condition. The location and the time delay in the response of the heater are considered as bifurcation parameters to obtain the stability boundaries. In the presence of non perfect impedance boundary condition, we find that the extent of globally unstable regime reduces and the bistable zone significantly increases. The quantitative changes in the stability boundaries and the bistable zone are investigated for different time lags. However, the nature of bifurcation remains sub critical and unaltered for the range of time delays considered in the present study.