Numerical Study on the Route of Flame-Induced Thermoacoustic Instability in a Rijke Burner

The self-excited thermoacoustic instability in a two-dimensional Rijke-type burner with center-stabilized premixed methane–air flame is numerically studied. simulation considers the reacting flow, dynamics, and radiation model to investigate important physical processes. A finite volume-based approach used simulate flows under both laminar turbulent flow conditions. Chemical reaction modeling conducted via finite-rate/eddy dissipation one-step mechanisms, heat flux characteristics are determined by using P-1 standard k-? model, respectively. steady-state first simulated for verification. Then, dynamic pressure, velocity, evolutions show onset growth rate of burner. Using fast Fourier transform (FFT) method, frequency limit cycle oscillation obtained, which agrees well theoretical prediction. pressure velocity along tube axis provide acoustic mode amplitude, also agreeing Finally, unsteady field at different times shows that flame-induced vortices occur inside combustor, temperature distribution indicates back-and-forth changes vary distance between honeycomb turn, forming forward feedback loop tube. results reveal route indicate periodical vortex formation breakdown Rijke burner, should be considered instability.