CAJ | 학술논문

应用无量纲分析方法，建立了矩形空腔内流体浮升流动的数学模型，研究了相同工况下不同高宽比对其流动换热的影响。研究结果表明：不同高宽比对流体的浮升流动具有较大影响，随着高宽比的增大，空腔内流体流动的层流过渡层向Ra值减小的方向偏移，且当Ra数一定时，Numean随高宽比迅速地达到最大值后缓慢减小；随着Ra值的增加，空腔中涡的数量逐渐增加，浮升流动强度增大，Numean增大，且Numean的最大值向高宽比减小的方向偏移。
응용무량강분석방법，건립료구형공강내류체부승류동적수학모형，연구료상동공황하불동고관비대기류동환열적영향。연구결과표명：불동고관비대류체적부승류동구유교대영향，수착고관비적증대，공강내류체류동적층류과도층향Ra치감소적방향편이，차당Ra수일정시，Numean수고관비신속지체도최대치후완만감소；수착Ra치적증가，공강중와적수량축점증가，부승류동강도증대，Numean증대，차Numean적최대치향고관비감소적방향편이。
In this paper, the mathematic model of buoyant lift flow in a rectangular cavity was developed by the dimensionless analysis.The effects of aspect ratio of the rectangular cavity on the heat convection were simulated and analyzed through this mathematic model under same working conditions.The results show that the aspect ra-tio of rectangular cavity has great effects on the character of buoyant lift flow and heat convection efficiency.With the aspect ratio increased, the transition layer of laminar flow has the tendency to decrease the Rayleigh number. When the Rayleigh number is kept constant, the average Nusselt number dramatically approaches the maximum and then decreases gradually.The eddy amount, intensity of buoyant flow and the average Nusselt number in-crease with the Rayleigh number.The maximum of average Nusselt number also has the tendency to move in the direction of smaller aspect ratio.