封闭腔内层流自然对流换热过渡层数值研究

对正方形空腔内的层流自然对流换热进行了数值模拟 ,用SIMPLE算法和乘方格式对该问题 (Ra =1× 10 3～ 1× 10 6)进行了详细的数值计算 .根据计算结果 ,在前人工作的基础上总结出封闭腔内层流自然对流换热的变化规律 ,提出了导热占主导地位的层流流动和导热与对流共时作用的层流流动的分界点 ,同时得出了两个区域的平均努塞尔数的计算公式 ,通过比较 ,表明其精度较以前的计算公式要高 .

Numerical Study on the Flow Transition in Laminar Natural Convection Flow in a Square Cavity

The numerical simulations have been undertaken for the benchmark problem of laminar natural convection flow and heat transfer in an enclosed square cavity. The SIMPLE arithmetic and power format are used to solve the conservation equations for laminar flow for a series of Rayleigh numbers reaching values up to 1×106. Some comparisons between the computational data and previous data and the correlations and further analyses are made. Based on the computational results, a new law of laminar natural convection flow and heat transfer is summarized on the basis of previous scholar's works. The flow transition is accurately proposed between the laminar flow predominated by the heat conduct and the laminar flow cooperated by the convection and the heat conduct. The average Nu correlations are made for representing the computational data and they are more precise than the previous correlations.