Magnetic Effect on the Goertler Vortices in Mixed Convection Flow over a Rotating Concave Surface

磁力效應對混合對流流經凹曲面邊界層渦流不穩定之研究

林明漢(Ming-Han Lin) ； 陳金帶(Chin-Tai Chen)

《中國機械工程學刊》 30卷1期 (2009/02) Pp. 15-23

https://doi.org/10.29979/JCSME.200902.0003

摘要

本文以數值實驗模擬磁力效應對強制對流流經凹曲面邊界層渦流不穩定之影響，使用線性穩定模式及實驗準則法訂定渦流發生點，本研究相關參數為普蘭特數，渦流波數，磁場參數Ha^2/Re，Grashof數及Goertler數；本研究顯示：順時針旋轉及磁力效應造成混合對流流經凹曲面邊界層渦流不穩定延緩發生。本文數值計算結果(Ha^2/Re=0)與實驗數據比較，在趨勢上相當吻合。

並列摘要

This paper presents a numerical study of magnetic effect on the formation of Goertler vortices in mixed convection flow over a heated rotating concave surface. The onset position characterized by the Goertler number G(subscript δ), depends on the Grashof number, the rotational number, the Prandtl number, the magnetic field parameter, and the wave number. The buoyancy force, the Lorentz force and the Coriolis force are found to significantly affect the flow structure and heat transfer of the flow. Negative rotation (clockwise) and external magnetic field stabilize the boundary layer flow on the concave surface. On the contrary, positive rotation (anticlockwise) destabilizes the flow. The numerical data show agreement with the experimental data.

並列關鍵字

mixed convection ； magnetic effect ； Goertler vortices ； rotation