Numerical simulation on combined heat loss of an environmental windy cylindrical cavity with bottom wall heated

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. ©2014 Chinese Society for Electrical Engineering.