论文标题
弥漫和准束辐射对自然对流的对称冷却案例的影响
Effects of Diffuse and Collimated Beam Radiation on a Symmetrical Cooling Case of Natural Convection
论文作者
论文摘要
在目前的工作中，已经研究了从底部加热的二维腔中对对称对流的对称冷却案例的弥散和准辐射的影响。腔体从底部加热，传热系数为50 W/m2k，自由流温度为305 K，而两个腔的垂直壁在296 K的温度下均等温壁。顶壁是绝热的，所有壁都是辐射热传递的不透明的壁。对于准确的情况，在左壁上创建了一个0.05的非二维宽度的小半透明窗口，并在此半透明窗口上以45的角度45施加了值1000 W/m2的准直辐射。结果表明，弥漫性辐射对腔体内两个卷的动力学几乎没有影响，但是，准束辐射会显着改变两个卷的动力学，也改变了传热特性。这进一步随流体的光学厚度而变化。对于透明流体的准直束，左涡流的尺寸大于右涡旋，而对于流体的非零光学厚度的准束趋势是反向趋势。
In the present work, the effects of diffuse and collimated radiation on the symmetrical cooling case of natural convection in a two-dimensional cavity heated from the bottom have been investigated, numerically. The cavity is convectively heated from the bottom with heat transfer coefficient of 50 W/m2K and free stream temperature 305 K, while both vertical walls of cavity are isothermal at temperature of 296 K. The top wall is adiabatic and all walls are opaque for radiation heat transfer. For collimated case, a small semitransparent window of non-dimensional width of 0.05 at height of 0.7 has been created on the left wall and a collimated irradiation of value 1000 W/m2 at an angle 45 is applied on this semitransparent window. The results reveal that the diffuse radiation has little effect on the dynamics of two rolls inside the cavity, however, collimated beam irradiation changes the dynamics of two rolls significantly and also the heat transfer characteristics. This further changes with the optical thickness of the fluid. The left vortex is bigger in size than the right vortex for collimated beam in transparent fluid, whereas, reverse trend is seen for collimated beam in non-zero optical thickness of the fluid.
