本文主要是探討液體噴流衝擊加熱片之熱傳分析研究，噴流出口設定為紊流流場，並且是均勻流，利用計算流體力學軟體進行分析，模擬出不同衝擊雷諾數、衝擊高度、噴嘴半徑所造成不同的熱傳效率與流場現象。
由數值模擬結果發現，整個流場在撞擊壁面後，可分為衝擊點、衝擊區、壁流區三個區域，而衝擊區過後存在一種稱為紊流發展區的流場，此區域的紊流強度對於衝擊冷卻的熱傳效率有相當大的影響。不同條件下的結果顯示，熱傳係數在衝擊點會有極大值，過了衝擊點其值便開始下降，當流體經過紊流發展區時，熱傳係數又會上升，產生第二個極大值，之後又會下降不再上升。
衝擊點紐塞數與噴嘴直徑沒有太大關係，而是與衝擊雷諾數成正比、衝擊高度成反比。

A numerical study has been conducted of the single-phase free water jets impinging normally against a flat uniform heat flux surface. An axisymmetric two dimension turbulent jet was modeled by using CFD software–FLUENT. The flow at the nozzle exit has a uniform velocity profile and is turbulent flow. The present investigation is performed for the jet Reynolds number ranging from 5000 to 20000, with a small impinging distance which is defined by dimensionless distance between the nozzle and plate surface ranging from 1.5 to 4.0 and a nozzle diameter ranging from 1.0 to 2.5 mm.
From the results of numerical simulation, we found that the flow structures of impinging jet can be divided three regions：free jet, impinging region and wall jet. There is a stagnation point on the center of the flat plate within the impinging region and the stagnation Nusselt Number is increasing with jet Reynolds Number for a given jet diameter. The local heat transfer coefficient has a local maximum value at the stagnation point, and decrease when the flow beyond the stagnation point. The local heat transfer coefficient has a second maximum value at the point where the distance from the stagnation is about 0.85 times jet diameter. This is because the turbulent intensity of flow characteristics. So there is an another region within the wall jet which is so-called developing turbulence region.

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