Effect of wall boundary conditions on the nonlinear response of turbulent premixed flames
| Autor: | Kun Luo, Yuzhou Cheng, Jianren Fan, Haiou Wang, Zongyan Li, Tai Jin |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Materials science Turbulence Flame structure General Physics and Astronomy 02 engineering and technology Mechanics 021001 nanoscience & nanotechnology 01 natural sciences Isothermal process lcsh:QC1-999 Physics::Fluid Dynamics Nonlinear system 0103 physical sciences Combustor Compressibility Boundary value problem Physics::Chemical Physics 0210 nano-technology Adiabatic process lcsh:Physics |
| Zdroj: | AIP Advances, Vol 11, Iss 1, Pp 015236-015236-12 (2021) |
| ISSN: | 2158-3226 |
| Popis: | Fully compressible Large Eddy Simulations (LES) are performed to investigate the effect of wall boundary conditions on the nonlinear response of turbulent premixed flames. For the unforced flames, the flame length and flame angle from the present LES results in the isothermal case are in better agreement with experimental results than those in the adiabatic case. For the forced flames, both amplitudes and phases of nonlinear flame response at moderate frequency are well reproduced in the isothermal case. While in the adiabatic case, the amplitudes are well reproduced, the prediction of phases is slightly underestimated. At high frequency, LES results from the isothermal case provide reasonable agreement with the experimental results in general, while the adiabatic case gives unreasonable prediction of nonlinear flame response. Results show that wall boundary conditions affect the spatial distributions of heat release fluctuations by changing the temperature field, which is affected by the evolutions of the flame structure and flow field in the nonlinear oscillation cycle. At moderate frequency, heat release fluctuations in different parts of the combustor are in phase, and wall boundary conditions have limited influence on the global flame response, while at high frequency, wall boundary conditions have significant influence on the global flame response since the heat release fluctuations in different parts of combustor are out of phase. Accurate prediction of flame response at high frequency needs accurate calculation of the wall temperature. |
| Databáze: | OpenAIRE |
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