中文摘要：

借助Fluent软件模拟了甲烷一空气扩散燃烧过程，对燃烧过程进行了熵产分析。单位体积内由导热和对流、粘性耗散、质量扩散和化学反应过程的不可逆性产生的局部熵产率通过用户自定义函数（user defined function，UDF）求解，由辐射过程的不可逆性导致的局部熵产率则通过对已求解的温度场进行后处理得到。结果表明对含有辐射换热的传热过程进行热力学分析时，辐射熵产不能忽略。在燃料和空气入口温度及壁面温度不变时，总熵产数随燃料入口雷诺数和玻尔兹曼数的增大分别先减小后增大。因此可以选择适当的燃料入口雷诺数和玻尔兹曼数使系统的总熵产数最小，从而提高能量利用效率。

英文摘要：

Entropy generation during methane-air diffusion combustion was studied. The numerical simulation of combustion was carried out with the help of Fluent CFD software. The entropy generation per unit volume due to heat conduction and convection, viscous dissipation, mass diffusion and chemical reaction was calculated by user defined function （UDF） post processing, and the entropy generation due to radiative transfer was calculated as post-processed quantities with the computed data of temperature. Numerical results show that the entropy generation due to radiative transfer can not be omitted in combustion processes. In the case that the temperatures of the inlet fuel and air and the top and bottom are not changed, the total entropy generation number first decreases with the increase of fuel inlet Reynolds number and Boltzmann number, and then increases. In order to improve energy utilization efficiency, an appropriate fuel inlet Reynolds number and Boltzmann number should be selected.