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对渗透壁面竖直平板Blasius流层流边界层流动熵产及传热熵产与总熵产的比值(Bejan数)进行了深入研究,将耦合的动量与能量偏微分方程组通过相似变换转换为非线性常微分方程组,用Runge-Kutta法求解获得了无量纲流函数与无量纲温度的相似解,进而研究了无量纲参数对熵产及Bejan数的影响.结果表明:吸入时最大熵产位于壁面处,吸入速度越大最大熵产越大,熵产随相似变量的增加单调下降;喷注速度越大壁面处熵产越小;近壁面处熵产随变黏度参数增大而增大,远离壁面处随喷注/吸入参数或变黏度参数的增大而减小;远离壁面处Bejan数随喷注/吸入参数或变黏度参数的增大而增大,近壁面处与此相反;熵产和Bejan数随着辐射参数和Reynolds数增大而减小,随着Biot数增大而增大;Biot数在0~2范围内对传热熵产的影响很剧烈,Biot数较小时总熵产由流动熵产控制,Biot数较大时总熵产由传热熵产控制;熵产随滑移参数的减小而增大,Bejan数随滑移参数的增大而增大;Grashof数对熵产的影响较大,在较大的Grashof数条件下熵产随相似变量的变化较剧烈;滑移参数越大,流动熵产越小,Bejan数越大.
The flow entropy and the ratio of thermal entropy production to total entropy production in the Blasius laminar flow at the vertical plate on the permeable wall are studied in detail. The coupled momentum and energy partial differential equations are transformed into Nonlinear Ordinary Differential Equations, the Runge-Kutta method is used to obtain the similar solutions of dimensionless flow function and dimensionless temperature, and the influence of dimensionless parameters on entropy yield and Bejan number is studied. The results show that the maximum entropy production Located at the wall surface, the larger the maximum entropy rate is, the more entropy rate is. The entropy rate decreases monotonously with the increase of similar variables. The larger the injection velocity is, the smaller the entropy rate is at the wall; the entropy yield increases with the increase of the viscosity coefficient , Which decreases with increasing injection / suction parameters or variable viscosity parameters away from the wall surface. Bejan number increases away from the wall surface with increasing injection / suction parameters or variable viscosity parameters, Entropy yield and Bejan number decrease with the increase of radiation parameters and Reynolds number and increase with increase of Biot number. Biot number has a strong influence on heat transfer entropy production in the range of 0 ~ 2. When Biot number is small The total entropy production is controlled by the flow entropy production, and the total entropy production is larger when the Biot number is larger Entropy production increases with the decrease of slip parameters, Bejan number increases with the increase of slip parameters, and Grashof number has a greater influence on entropy production. Under the condition of larger Grashof number, Entropy yield changes more drastically with similar variables. The larger the slip parameter is, the smaller the entropy yield is and the larger the Bejan number is.