中文摘要：

对流动分岔后的超临界二氧化碳在平面对称突扩管中进行强迫对流换热进行了数值模拟，研究了热流密度在流体发生流动分岔现象后流动特性的影响。计算结果表明：随着热流密度的增加，临界雷诺数和转换雷诺数减小，流动稳定性遭到削弱；对应于相同的雷诺数，由于流动分岔引起的不对称压力分布随着热流密度的增加对应于突扩管上、下半部有不同变化规律，这使得对应回流区的大小分别减小和增大。

英文摘要：

Convective heat transfer of supercritical C02 in plane symmetric sudden expansion duct was investigated numerically. Effects of wall heat flux on the flow characteristics of the bifurcated flow were studied. With the increasing of wall heat flux, the critical Reynolds number and transitional Reynolds number and transitional Reynolds number decrease, and the flow stability was reduced. At the same Reynolds number, the asymmetric distributions of pressure varied differently for the upper and lower half part of the duct, which results in the decrease and increase of recirculation region, respectively