變黏度與吸入對具有均勻表面熱通量垂直圓錐的自然對流邊界層流動之影響

Effects of Variable Viscosity and Suction on Natural Convection Boundary Layer Flow over a Vertical Cone with Uniform Surface Heat Flux

本文研究變黏度與吸入對垂直圓錐之自然對流邊界層流動與熱傳之影響。此一垂直圓錐承受均勻表面熱通量。統制方程式先被轉換為一組非相似邊界層偏微分方程式，再以三次樣條配置法解所得之邊界層偏微分方程式。局部表面溫度呈現為下列參數之函數：吸入變數、黏度變動參數與普郎特數。結果顯示，增大吸入變數或黏度變動參數會減少局部表面溫度。當吸入變數變大時，黏度變動參數對局部表面溫度之影響會變大。而且隨著普郎特數增大，局部表面溫度會減少。

This work studies the effects of variable viscosity and suction on natural convection boundary layer flow and heat transfer in a vertical cone. The vertical cone is subjected to a uniform surface heat flux. The governing equations are transformed into nonsimilar boundary layer partial differential solutions, and the derived boundary layer partial differential equations are then solved using the cubic spline collocation method. The local surface temperature is presented as functions of the suction variable, viscosity-variation parameter, and Prandtl number. Results show that an increase in the suction variable or the viscosity-variation parameter tends to decrease the local surface temperature. The effect of the viscosity-variation parameter on the local surface temperature is significant for large values of suction variables. Moreover, the local surface temperature decreases as the Prandtl number is increased.