论文标题
热膨胀对泰勒色散控制扩散火焰的影响
Effects of thermal expansion on Taylor dispersion-controlled diffusion flames
论文作者
论文摘要
开发了一种理论分析，以研究由于热量释放而导致的气体膨胀对管流中不稳定扩散火焰的影响，在该管道流中，泰勒的分散过程控制了反应物的混合，从而扩展了基于热 - 散热模型的先前开发的理论。首先显示，有时比径向扩散时间大，在第一个近似值中，气体膨胀引起的压力梯度与驱动流动的盛行压力梯度相比很小，这表明对背景速度轮廓的校正很小。为Burke-Schumann火焰求解了对速度成分的校正以及浓度，温度和密度等领先的混合变量。由于有效的泰勒扩散系数依赖于气体密度，因此观察到了来自热 - 扩散模型的预测中的定量，有时是定性的出发。
A theoretical analysis is developed to investigate the effects of gas expansion due to heat release on unsteady diffusion flames evolving in a pipe flow in which the mixing of reactants is controlled by Taylor's dispersion processes thereby extending a previously developed theory based on the thermo-diffusive model. It is first shown that at times larger than radial diffusion times, the pressure gradient induced by the gas expansion is, in the first approximation, small in comparison with the prevailing pressure gradient driving the flow, indicating that corrections to the background velocity profile are small. The corrections to the velocity components along with the leading-order mixing variables such as the concentrations, temperature and density are solved for a Burke-Schumann flame. Due to the dependence of the effective Taylor diffusion coefficients on the gas density, quantitative and sometimes qualitative departures in predictions from the thermo-diffusive model are observed.
