湍流乙烯扩散火焰中碳黑的数值模拟研究
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摘要
以德国航空航天中心湍流乙烯扩散火焰为对象,基于k-epsilon湍流模型和稳态扩散火焰面结合假定概率密度函数(PDF)模型,研究了Moss-Brookes和Moss-Brookes-Hall碳黑模型中不同氧化组合方式以及碳黑成核速率常数C_α对碳黑浓度分布和温度的影响。其中,辐射模型基于球谐函数法(P1)和灰气体加权和模型(WSGG)。研究结果表明:在Moss-Brookes和Moss-Brookes-Hall碳黑模型中FJ-equilibrium、Lee-instantaneous两种氧化组合方式能够较好地预测乙烯扩散火焰的碳黑分布位置,默认的碳黑成核速率常数C_α会过高地预测碳黑浓度,随着C_α的减小碳黑浓度减小,修正碳黑成核速率常数C_α后能准确预测碳黑浓度和温度分布。
Based on the k-epsilon turbulence model and the steady diffusion flamelet model combined with the assumed probability density function( PDF) model,the turbulent ethylene diffusion flame of the German Aerospace Center was used to study the effects of different oxidation combination approaches and model constant for soot inception rate( C_α) on the soot concentration distribution and temperature distribution in Moss-Brookes and Moss-Brookes-Hall soot models. Among them,the radiation model is based on spherical harmonic function method( P1) and weighted sum of gray gases model( WSGG). The results showed that FJ-equilibrium and Lee-instantaneous oxidation combination approaches in the Moss-Brookes and Moss-Brookes-Hall soot models can predict the location of soot distribution well,but the default model constant for soot inception rate would be too high to predict theconcentration of soot in the ethylene diffusion flame. With the decrease of model constant for soot inception rate, the concentration of soot decreased. The soot concentration and temperature distribution can be predicted accurately with corrected model constant for soot inception rate.
Based on the k-epsilon turbulence model and the steady diffusion flamelet model combined with the assumed probability density function( PDF) model,the turbulent ethylene diffusion flame of the German Aerospace Center was used to study the effects of different oxidation combination approaches and model constant for soot inception rate( C_α) on the soot concentration distribution and temperature distribution in Moss-Brookes and Moss-Brookes-Hall soot models. Among them,the radiation model is based on spherical harmonic function method( P1) and weighted sum of gray gases model( WSGG). The results showed that FJ-equilibrium and Lee-instantaneous oxidation combination approaches in the Moss-Brookes and Moss-Brookes-Hall soot models can predict the location of soot distribution well,but the default model constant for soot inception rate would be too high to predict theconcentration of soot in the ethylene diffusion flame. With the decrease of model constant for soot inception rate, the concentration of soot decreased. The soot concentration and temperature distribution can be predicted accurately with corrected model constant for soot inception rate.
引文
[1] RAMAN V,FOX R O. Modeling of Fine-Particle Formation in Turbulent Flames[J]. Annual Review of Fluid Mechanics,2016,48(48):159-190.
[2] MODEST M F. Radiation characteristics and turbulenceradiation interactions in sooting turbulent jet flames[J].Combustion Theory&Modelling,2010,14(1):105-124.
[3] JOHANSSON R,BO L,ANDERSSON K,et al. Influence of particle and gas radiation in oxy-fuel combustion[J].International Journal of Heat&Mass Transfer,2013,65(5):143-152.
[4] KENNEDY I M. Models of soot formation and oxidation[J]. Progress in Energy&Combustion Science,1997,23(2):95-132.
[5] BROOKES S J,MOSS J B. Predictions of soot and thermal radiation properties in confined turbulent jet diffusion flames[J]. Combustion&Flame,1999,116(4):486-503.
[6] MOSS J B,STEWART C D,SYED K J. Flowfield modelling of soot formation at elevated pressure[J]. Symposium on Combustion,1989,22(1):413-423.
[7] SIEWARI C D,SYED K J,MOSS J B. Modelling Soot Formation in Non-premixed Kerosene Air Flames[J].Combustion Science&Technology,2007,75(4/5/6):211-226.
[8] MOSS J B,STEWART C D. Flamelet-based smoke properties for the field modelling of fires[J]. Fire Safety Journal,1998,30(3):229-250.
[9] PANG K M,NG H K,GAN S. Simulation of temporal and spatial soot evolution in an automotive diesel engine using the Moss-Brookes soot model[J]. Energy Conversion&Management,2012,58(2):171-184.
[10] PANG K M,NG H K,GAN S. Development of an integrated reduced fuel oxidation and soot precursor formation mechanism for CFD simulations of diesel combustion[J].Fuel,2011,90(9):2902-2914.
[11] RAJESHIRKE P,YADAV R,NAKOD P,et al. Parametric study of Moss-Brookes(MB)and Moss-Brookes-Hall(MBH)model constants for prediction of soot formation in a turbulent hydrocarbon flames[J]. Chemical Physics Letters,2013,372(1):275-281.
[12] WEN Z,YUN S,THOMSON M J,et al. Modeling soot formation in turbulent kerosene/air jet diffusion flames[J].Combustion&Flame,2003,135(3):323-340.
[13] HALL R J,SMOOKE M D,COLKET M B. Predictions of Soot Dynamics in Opposed Jet Diffusion Flames[J].Physical and Chemical Aspects of Combustion,1997,189-229.
[14] FENIMORE C P,JONES G W. Oxidation of soot by hydroxyl radicals[J]. J Phys Chem,1967,71(3):593-597.
[15] LEE K B,THRING M W,BEéR J M. On the rate of combustion of soot in a laminar soot flame[J]. Combustion&Flame,1962,6(62):137-145.
[16] KOHLER M,GEIGLE K P,MEIER W,et al. Sooting turbulent jet flame:characterization and quantitative soot measurements[J]. Applied Physics B,2011,104(2):409-425.
[17] BUSUPALLY M R,DE A. Numerical modeling of Soot formation in a turbulent C2H4/air diffusion flame[J]. International Journal of Spray&Combustion Dynamics,2016,8(2):67-85.
[18] ZHANG J,SHADDIX C R,SCHEFER R W. Design of“model-friendly”turbulent non-premixed jet burners for C2+hydrocarbon fuels.[J]. Review of Scientific Instruments,2011,82(7):49.
[19] WANG H,KOOK S,DOOM J,et al. Understanding and predicting soot generation in turbulent non-premixed jet flames.[J]. Social Science Electronic Publishing,2010,4(4):206-207.
[20] RANZI E,FRASSOLDATI A,GRANA R,et al. Hierarchical and comparative kinetic modeling of laminar flame speeds of hydrocarbon and oxygenated fuels[J]. Progress in Energy&Combustion Science,2012,38(4):468-501.
[21] DORIGON L J,DUCIAK G,BRITTES R,et al. WSGG correlations based on HITEMP2010 for computation of thermal radiation in non-isothermal,non-homogeneous H2O/CO2mixtures[J]. International Journal of Heat and Mass Transfer,2013,64:863-873.
[2] MODEST M F. Radiation characteristics and turbulenceradiation interactions in sooting turbulent jet flames[J].Combustion Theory&Modelling,2010,14(1):105-124.
[3] JOHANSSON R,BO L,ANDERSSON K,et al. Influence of particle and gas radiation in oxy-fuel combustion[J].International Journal of Heat&Mass Transfer,2013,65(5):143-152.
[4] KENNEDY I M. Models of soot formation and oxidation[J]. Progress in Energy&Combustion Science,1997,23(2):95-132.
[5] BROOKES S J,MOSS J B. Predictions of soot and thermal radiation properties in confined turbulent jet diffusion flames[J]. Combustion&Flame,1999,116(4):486-503.
[6] MOSS J B,STEWART C D,SYED K J. Flowfield modelling of soot formation at elevated pressure[J]. Symposium on Combustion,1989,22(1):413-423.
[7] SIEWARI C D,SYED K J,MOSS J B. Modelling Soot Formation in Non-premixed Kerosene Air Flames[J].Combustion Science&Technology,2007,75(4/5/6):211-226.
[8] MOSS J B,STEWART C D. Flamelet-based smoke properties for the field modelling of fires[J]. Fire Safety Journal,1998,30(3):229-250.
[9] PANG K M,NG H K,GAN S. Simulation of temporal and spatial soot evolution in an automotive diesel engine using the Moss-Brookes soot model[J]. Energy Conversion&Management,2012,58(2):171-184.
[10] PANG K M,NG H K,GAN S. Development of an integrated reduced fuel oxidation and soot precursor formation mechanism for CFD simulations of diesel combustion[J].Fuel,2011,90(9):2902-2914.
[11] RAJESHIRKE P,YADAV R,NAKOD P,et al. Parametric study of Moss-Brookes(MB)and Moss-Brookes-Hall(MBH)model constants for prediction of soot formation in a turbulent hydrocarbon flames[J]. Chemical Physics Letters,2013,372(1):275-281.
[12] WEN Z,YUN S,THOMSON M J,et al. Modeling soot formation in turbulent kerosene/air jet diffusion flames[J].Combustion&Flame,2003,135(3):323-340.
[13] HALL R J,SMOOKE M D,COLKET M B. Predictions of Soot Dynamics in Opposed Jet Diffusion Flames[J].Physical and Chemical Aspects of Combustion,1997,189-229.
[14] FENIMORE C P,JONES G W. Oxidation of soot by hydroxyl radicals[J]. J Phys Chem,1967,71(3):593-597.
[15] LEE K B,THRING M W,BEéR J M. On the rate of combustion of soot in a laminar soot flame[J]. Combustion&Flame,1962,6(62):137-145.
[16] KOHLER M,GEIGLE K P,MEIER W,et al. Sooting turbulent jet flame:characterization and quantitative soot measurements[J]. Applied Physics B,2011,104(2):409-425.
[17] BUSUPALLY M R,DE A. Numerical modeling of Soot formation in a turbulent C2H4/air diffusion flame[J]. International Journal of Spray&Combustion Dynamics,2016,8(2):67-85.
[18] ZHANG J,SHADDIX C R,SCHEFER R W. Design of“model-friendly”turbulent non-premixed jet burners for C2+hydrocarbon fuels.[J]. Review of Scientific Instruments,2011,82(7):49.
[19] WANG H,KOOK S,DOOM J,et al. Understanding and predicting soot generation in turbulent non-premixed jet flames.[J]. Social Science Electronic Publishing,2010,4(4):206-207.
[20] RANZI E,FRASSOLDATI A,GRANA R,et al. Hierarchical and comparative kinetic modeling of laminar flame speeds of hydrocarbon and oxygenated fuels[J]. Progress in Energy&Combustion Science,2012,38(4):468-501.
[21] DORIGON L J,DUCIAK G,BRITTES R,et al. WSGG correlations based on HITEMP2010 for computation of thermal radiation in non-isothermal,non-homogeneous H2O/CO2mixtures[J]. International Journal of Heat and Mass Transfer,2013,64:863-873.