Free Convection of a Nanofluid about a Vertical Truncated Cone

奈米流體在垂直截圓錐表面之自然對流

鄭慶陽(Ching-Yang Cheng)

《中國機械工程學刊》 37卷3期 (2016/06) Pp. 213-219

摘要

本文研究奈米流體在垂直截圓錐表面之自然對流熱傳遞。而此奈米流體承受均勻壁溫。本文邊界條件採用零奈米粒子通量，而不是均勻奈米粒子容積分率，如此得到之結果較為實際有用。先導出非相似偏微分方程式，再以三次樣線配置法求解。本文研究布朗運動參數、浮力比、路易士數、普郎特數與熱泳參數等參數對熱傳遞之影響。結果顯示，增加普郎特數與流線座標會增大局部紐塞爾數。而且增大路易士數與熱泳參數會降低局部紐塞爾數。而局部紐塞爾數則幾乎不受布朗運動參數與浮力比之影響。

並列摘要

This work studies the free convection heat transfer of a nanofluid about a vertical truncated cone with uniform wall temperature. Instead of using the boundary conditions of uniform wall nanoparticle volume fraction, we employ a boundary condition of zero nanoparticle flux to obtain results more realistic and useful. Nonsimilar partial differential quations are derived and then solved by the cubic spline collocation method. The effects of the Brownian motion parameter, buoyancy ratio, Lewis number, Prandtl number, and thermophoresis parameter on the heat transfer have been studied. Results show that increasing the Prandtl number and the streamwise coordinate tends to increase the local Nusselt number. Furthermore, increasing the Lewis number and the thermophoresis parameter decreases the local Nusselt number. Moreover, the local Nusselt number is almost independent of the Brownian motion parameter and the buoyancy ratio.

並列關鍵字

free convection ； heat transfer ； vertical truncated cone ； nanofluid