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以封闭厂房内自然对流传热为研究对象,采用计算流体力学、传热学理论进行数值计算,研究了Ra在103～108之间时,封闭厂房内流体流线、等温线的分布特征和Nu数的变化,以及中心线上无量纲温度T、量纲速度Ux、Vy在不同Ra下的变化关系。研究结果表明:随着Ra的增大,厂房内的热传输形式由热传导逐渐向对流传热转换,且对流强度分布越不均匀,流线形状发生相应的改变;水平中心线上的无量纲温度由一条近似于斜率为45°的曲线逐渐变成温度急剧变化的“ㄣ”型曲线;竖直中心线与水平中心线上无量纲速度Ux、Vy随着Ra的增大而变大,Ux、Vy大小及方向的改变导致腔内涡流的产生;Nu随着Ra的增大而增大,二者的相关曲线呈幂指数关系。
Taking the natural convection heat transfer in the closed workshop as the research object, the computational fluid dynamics and heat transfer theory were used to calculate the distribution of fluid flow and isotherms in the closed factory when Ra was between 103 and 108. Number of changes, and centerless dimensionless temperature T, dimensional velocity Ux, Vy in different Ra under the relationship. The results show that with the increase of Ra, the form of heat transfer in the plant gradually changes from heat conduction to convective heat transfer, and the more uneven the convective intensity distribution, the streamline shape changes correspondingly; the dimensionless temperature on the horizontal centerline From a curve approximating to a slope of 45 °, it gradually becomes a curve of “ㄣ ” type whose temperature changes abruptly; dimensionless velocities Ux and Vy on the vertical centerline and the horizontal centerline become larger as Ra increases, Ux, Vy changes in size and direction lead to the generation of vortexes in the cavity; Nu increases with the increase of Ra, the correlation curve of the two shows a power exponential relationship.