化学反应时滞对燃烧不稳定性的影响

摘要

对某实验贫油预混燃烧室内的不稳定燃烧的触发和特性进行了数值研究。应用非定常N-S方程，Realizable k-ε湍流模型和 EDC 燃烧模型，对燃烧室在燃用甲烷和氢气两种情形下的燃烧及压力振荡特性进行数值分析，在这两个情形中观察到了稳定和不稳定燃烧两种情况。研究表明：同一实验形体在相同计算条件下燃用不同燃料会获得不同的火焰振荡特性，这取决于燃料喷注位置到火焰前沿的化学反应时滞。%Computational fluid dynamics technology is adopted to study the combustion instability in an experimental combustor.Transient N-S equations are applied with the Realizablek-ε turbulence model and eddy dissipation con-cept(EDC) model for two cases with the fuel of methane and hydrogen to acquire the numerical analysis of combustion and pressure oscillation,and both stable and unstable combustion can be seen in these two cases.This study shows that different combustion oscillation characteristics can be achieved in one combustor when using different fuels in the same calculation conditions,which depends on the time-delay from the fuel injection location to the flame front.