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.
引文
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