本文探討運用大渦流模擬分析突起散熱片之三維暫態的流場及熱傳現象。本文利用有限體積法(FVM)離散Navier-Stokes方程式和能量方程式並化成代數方程組。接著運用解壓力耦合方程的半隱式方法(SIMPLE, Semi-Implicit Method for Pressure-Linked Equation) 迭代至收斂，獲得流場及溫度場。此模擬將九片鰭片放置於490 mm x34 mm x245 mm通道內之底面，改變突起高度(0, 0.4, 0.8, 1.2 mm)和雷諾數(3500, 5000, 6500)，分析不考慮重力作用強制對流之溫度場與速度場分佈。
研究結果顯示:突起鰭片可以在鰭片間產升渦流，提高突起高度會影響內部和周圍的流場。從鰭片之平均紐賽數上看到，在Re等於6500時，0.8 mm高度鰭片之平均紐賽數約比平面鰭片高2%，而高度1.2 mm之突起鰭片也會追上。而在低雷諾數時，平面的鰭片有較高之平均紐賽數，但亦接近0.8 mm高度突起鰭片之平均紐賽數，而0.4 mm 突起鰭片之平均紐賽數為最低。

This study investigates the transient three-dimensional heat transfer of fin module by LES in forced convection and numerically analyzes the turbulent flow field and heat transfer performance. The Navier-Stokes equations and energy equation are constructed by the Finite Volume Method (FVM) and then are discretized to a system of algebraic equations. They can be solved by semi-implicit method for pressure-linked equation (SIMPLE). The solutions must be iterated to converge within each step to obtain the temperature and flow field.
This simulation places a nine fins on the bottom surface of a channel (490 mm x34 mm x245 mm) and changes the height of dimple (0, 0.4, 0.8 and 1.2 mm) with three different Re (3500, 5000 and 6500) to investigate the temperature and flow field without gravity in forced convection.
The results indicated that the dimpled fin can generate vortex between fins, and increases the influences of height of dimple the flow field in and around fins. From averaged Nu profiles, the Nu of F2 (0.8 mm) is higher than that of F0 (0 mm) about 1.9%, and the Nu of F3 becomes more close to that of F0 at Re=6500. At low Re, the Nu of F0 is the highest, but that of F2 is close and that of F1 is the lowest.

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