【摘要】 文章对内置等温生热体的三角形腔体内空气自然对流换热进行数值模拟。生热体为矩形,位于垂直边上,且温度恒定,三角形斜边的边界温度恒定且低于生热体温度,其余两边绝热。通过有限元方法对不同瑞利数(Ra)下的不同高宽比三角形腔体进行分析,得出腔体内空气的流线图、等温线分布图以及生热体表面空气的努塞尔数Nu与Ra的关系。结果表明,随着Ra的增加,腔内空气自然对流方式由层流向湍流转变,主要的传热方式由热传导转变为对流换热,且较小的高宽比更利于腔内流动和传热。更多还原

【Abstract】 Natural convection of air in triangular enclosures with isothermal heater was analyzed by numerical simulation.The temperature of the rectangular heater located on the vertical side kept constant.The hypotenuse temperature also kept unchanged,which was lower than the heater,and the remaining sides of the triangle were assumed to be adiabatic.Different triangular cavity aspect ratios under different Rayleigh numbers(Ra)were analyzed by using finite element method.The streamline and isotherm distributions were obtained as well as the relationship between Nusselt number(Nu)and Rayleigh number of the air on the heater’s surface.The results showed that with the increase of Rayleigh number,the laminar natural convection turned into turbulent,and the main way of heat transfer changed from heat conduction to convective heat transfer.It was also found that smaller cavity aspect ratio contributed more effective heat transfer.更多还原