中文摘要：

在考虑物性变化的基础上,对环境风（不同风速V和风向角α）下一侧全开圆柱形腔体仅底面受到均匀热流加热时的耦合热损失（对流、辐射和导热）特性进行三维数值模拟,得到了腔体内部和腔体开口面的温度和速度分布以及对流热损失平均努塞尔数Nuc、辐射热损失平均努塞尔数Nur随风速V和风向角α的变化曲线。结果表明：当风向角α=90°时,腔体内部和开口面附近的温度分布和速度分布与无风时十分类似,但风向角为其他值时,其分布规律与无风时差异很大;垂直风（α=90°）时,随着V的增大,Nuc缓慢减小而Nur缓慢增加,其他风向时,随着V的增大,Nuc逐渐增大而Nur逐渐减小;风速不变时,存在临界的风向角α使得Nuc最大,同时Nur达到最小值。

英文摘要：

Accounting for variable properties of fluid, the effects of the environmental wind speed and wind incidence angle on combined heat loss（convection, radiation and conduction） characteristics of a cylindrical cavity were studied by 3D numerical method. The cavity is a fully open one, with only bottom wall heated by constant heat flux. Temperature contours inside the cavity and velocity contours on the aperture plane were presented. The variations of average convection heat loss Nusselt number Nuc and average radiation heat loss Nusselt number Nur with wind speed and wind incidence angle were analyzed respectively. Results reveal that the temperature contours inside the cavity and the velocity contours on the aperture plane under environmental wind are very different from that of no wind case except for head-on wind（α=90°）. For head-on wind, with the increasing of wind speed, Nuc goes down slowly and Nur increases monotonously. While for other wind incidence angles, the tendency is exactly opposite. For certain wind speed, there exists critical wind incidence angle which corresponds to maximum of Nuc and minimum of Nur.