积分降重法求解辐射直接交换面积

直接交换面积的定义一般涉及4～6重积分,采用直接积分算法计算时耗费大量的机时,使段法模型应用受到很大的制约.利用积分数学运算公式,推导了基于积分降重法的辐射直接交换面积表达式.采用高斯积分法分别求解了三维封闭体系下的积分降重法及直接积分算法的辐射直接交换面积.与直接积分算法计算结果的比较表明,采用积分降重法求解直接交换面积的计算结果很好地满足了直接交换面积的完整性和互换性原则,同时提高了计算精度,大幅减少了计算时间

Calculation of Radiative Direct Exchange Areas Using a Reduced Integration Scheme

The definition of radiative direct-exchange areas (DEA) are usually involves four sixfold integral in solution, and long-time computation is therefore unavoidable if using direct integral, thus restricting greatly the application of zone model. Then, the expressions of a reduced integration scheme are derived from conventional integral formulae to solve the radiative direct-exchange areas, and the Gaussian quadrature is introduced into the solutions to the radiative direct-exchange areas within 3-D closed system by either the reduced integration scheme or the direct integral. Compared with the result by direct integral, the result by reduced integration scheme not only satisfies well both the reciprocity and integrality as required by the radiative direct-exchange areas but also improves the computing accuracy with computing time shortened greatly.