非灰系统当量灰吸收系数的反演

Equivalent gray absorption coefficient obtained by inverse analysis in non-gray gases system

提出了一种由气体温度场反向分析计算气体当量灰吸收系数的方法.采用段法(区域法)求解正问题,反演中采用求目标函数极小值的共轭梯度法.以直通式实验炉的测量数据为求解条件,用该计算得到了炉内气体介质当量灰吸收系数的分布.数值模拟结果表明,段法与共轭梯度法结合可以较好地反演非灰系统的当量灰吸收系数.与指数宽带段法模型结果的比较表明,反演得到的当量灰吸收系数具有与指数宽带模型相当的精度,但计算量小于宽带模型的1/10.

An inverse radiation analysis is presented for calculating the distribution of equivalent gray absorption coefficients from the temperature measurement in a non-gray gases system, where radiation conduction and convection occur simultaneously. The energy equation is solved by the zonal method, and the inverse radiation problem is solved through the minimization of performance function with the conjugated gradient method. Taking the measurement results of an experimental furnace as the solution condition, the equivalent gray absorption coefficient distribution is obtained by the presented method. Results show that the zonal method combined with the conjugate gradient method can solve the equivalent gray absorption coefficient well in the non-gray gases system. Comparison with the exponential wide band model shows that the equivalent gray absorption coefficient has the accuracy with the exponential wide band model, while the calculation time is less than a tenth.