本文是使用數值方法來分析蒸汽腔體內於穩態時其溫度場及流場之狀況。利用計算流體力學軟體FLUENT 6.2來模擬分析。模擬的蒸汽腔體根據Koito等人(2006) 所給定外形大小做三維數值模擬分析，工作流體為水及飽和水蒸汽，分析在不同的冷卻氣溫、加熱量及加熱面積下其溫度分佈和流場變化並和Koito等人(2006)的實驗做比較。
由數值結果可以看出在散熱面的溫度分佈均勻，從剖面圖亦可看到毛細結構靠近熱源的地方溫度梯度最大，而液流壓降遠大於蒸汽壓降和重力壓降，而要使工作流體能回流而不會空燒，毛細壓降要能大於液流壓降；跟Koito等人(2006)的實驗比較，結果相當一致，但當輸入熱量較大其溫度誤差也稍變大。在不同的冷卻氣溫、加熱量下，蒸汽腔體的熱阻變化不大；當冷卻氣溫越高及輸入熱量越大，蒸汽區內的工作流體密度變大其流速變慢；毛細結構的液流壓降在不同的冷卻氣溫下都一樣，但在輸入熱量越大其液流壓降越大；當熱源面積變小則熱阻變大，而毛細結構的溫度梯度也變大，故蒸汽區內流速也變大，而其液流壓降也較大。

This study used numerical method to analyze the thermal and fluid phenomena in a vapor chamber and the CFD software FLUENT 6.2 was used to do the simulation. The shape of vapor chamber was the same as in Koito et al. study (2006). The working fluid was water and the results of the analysis on the thermal and fluid phenomena were compared with the experiment results of Koito et al. (2006) for different cooling air temperatures, heat fluxes, and heat source sizes.
The numerical results showed that temperature of the cooling surface was uniform; from the cross-sectional view, the liquid –wick region near heat source had the largest temperature gradient and liquid flow had the maximum pressure drop in the vapor chamber. The capillary pressure head necessary to circulate the working fluid inside the vapor chamber must be larger than the pressure drop of liquid in the liquid-wick region. The average cooling surface temperature and the maximum temperature on bottom surface was close to the experimental result of Koito et al. (2006), but the larger the heat flux, the more the difference. Thermal resistance remained the same for different cooling air temperatures and heat fluxes. With higher cooling air temperature and heat flux, the velocity magnitude in vapor region was lower. In liquid-wick region, the liquid pressure drop was the same for different cooling air temperatures and was larger for higher heat flux. When the heat source size was smaller, the thermal resistance was found to be higher and the temperature gradient was larger. The pressure drop of liquid in liquid-wick region and velocity magnitude in vapor region was also higher.

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