对多孔介质中的往复式超绝热燃烧(简称为RSCP)进行了二维数值模拟,采用辐射传递的有限体积法求解了固相能量方程中的辐射源项.研究了预混气体流速、当量比和换向半周期等主要操作参数对RSCP系统中的温度分布、放热率、辐射热流量和辐射效率的影响,结果表明,有限体积法可以实现光学厚介质的非表面辐射流场与燃烧反应的耦合计算;RSCP燃烧器内部温度场呈典型的梯形,辐射热流近似正弦分布;在相同操作条件下,与常规多孔介质预混燃烧相比,RSCP燃烧器有更好的热结构和更高的辐射效率。
Reciprocating superadiabatic combustion in porous media (RSCP for short) is numerically studied. The finite volume method is used to solve the radiative source term in the energy equation of solid phase. The influences of the dominating working parameters, such as flow velocity of the premixed gases, equivalence ratio and half cycle on the temperature distributions, heat release rate, radiation flux and radiation efficiency are discussed. It is shown that coupling calculation of flow field, combustion reaction and volume radiation of the optical thick media is successively achieved and heat radiation should not be neglected in the modeling of premixed combustion in porous media. The temperature profile inside the RSCP combustor has a typical trapezoidal shape and the profile of radiation fluxes is similar to sinusoidal shape. Compared to the conventional premixed combustion system in porous media with the same working parameters, combustion behavior in RSCP combustor is superior, for example, the better thermal structure and higher radiation efficiency.