磁場對承受定值表面熱與質量通量的雙分層多孔介質內垂直圓錐雙擴散對流之影響Magnetic Field Effects on Double Diffusive Convection from a Vertical Cone in Doubly Stratified Porous Media with Constant Surface Heat and Mass Fluxes

                             摘要

本文研究橫向磁場對雙分層多孔介質內垂直圓錐雙擴散對流之影響，此一垂直圓錐有定值之表面熱通量與質量通量。本文應用近似變數將統制偏微分方程式轉換為一組常微分方程式。再以三次樣線配置法求數值解。本文研究磁參數、熱分層參數、質量分層參數、路易士數與浮力比等參數對局部表面溫度與局部表面濃度之影響。對相似特例所得之解與與已發表之論文結果比較相當吻合。增加熱分層參數會減少局部表面溫度。局部表面濃度會隨著質量分層參數之增加而減少。而增大磁參數則會增大局部表面溫度與濃度。

This study examines the effects of transverse magnetic fields on the double diffusive convection about a vertical cone in a doubly stratified porous medium with constant surface heat and mass fluxes. This paper uses similarity variable to transform the governing partial differential equations into a system of ordinary differential equations, which are solved numerically by the cubic spline collocation method. The effects of magnetic parameters, thermal stratification parameters, mass stratification parameters, Lewis numbers, and buoyancy ratios on the local surface temperature and the local surface concentration are studied. A comparison with previously published results on the similar special cases shows an excellent agreement. The local surface temperature tends to decrease as the thermal stratification parameter is increased. Moreover, an increase in the mass stratification parameter leads to a decrease in the local surface concentration. Furthermore, increasing the magnetic parameter tends to increase the local surface temperature and concentration.