熱氣泡式微型泵浦之應用研究與模擬分析

近年來由於微系統製程技術不斷的提昇，在微系統技術中的微幫浦技術日益成熟，由於微泵浦所噴出的液滴顆粒非常的微小，液滴品質相當均勻，且可準確的控制其噴量，對於需要準確冷卻能力的電子散熱方面便顯得相當可行，此外因微泵浦技術應用的領域範圍越來越廣泛，但若是能將微泵浦整體效率的提高，將更有助於微泵浦應用的發展，因此在本次研究中，除了探討微泵浦技術在熱板冷卻散熱方面的研究外，另一方面也探討改良式微泵浦對於整體噴射及回補效率的研究，研究中利用微系統領域常用的計算流體力學分析軟體（CFD-RC）進行相關分析工作，藉以模擬陣列微泵浦之噴射液滴速度、形狀及軌跡，在微液滴衝擊熱板的分析中將針對在不同流體、液滴噴射距離、液滴量大小及熱板表面親水性影響等變數，以流體力學分析軟體進行分析探討液滴在各變數下，撞擊到熱板產生的濺射情況及對熱板熱傳的變化，而在改良式微泵浦噴頭的的研究中則是分析在不同流體及陣列效應下，以流體力學分析軟體分析液滴的噴射情況，結果顯示熱板表面親水性越好（即接觸角角度越小）、衝擊熱板後較容易擴散的乙醇以及較遠的噴射距離影響液滴衝擊熱板力道較大液滴越容易完全濺射至熱板表面對於熱板表面熱量的帶走有較大的效果，而改良式噴頭腔體因連接一漸擴及漸縮流道，受到流道的影響，在與前人的模擬結果比較有較快的液滴噴射速度及較好的工作流體回補率，在實驗部分利用Schlieren所拍攝出來的影片可以清楚的看到微液滴噴射到熱板後受熱板加熱而蒸發為氣相，而在改良式微泵浦的部分，在模擬與實驗觀測結果中，液滴形狀外觀皆非常相似，連接漸縮流道的微泵浦【A】液滴噴出速度較連接漸擴流道的微泵浦【B】為快估算約為快1m/s。

關鍵字

熱泡式陣列微泵浦；計算流體力學；微液滴衝擊

並列摘要

In recent years, as the micro-system fabrication technology continues to advance, the production of many products has employed micro-system fabrication technology for mass production, thus, to reduce the cost and improve the product quality. Among the micro-system technology, micropump technology has gradually developed. Since the droplets dispersed by the micropump are minute, the droplet quality is consistent, and the amount of injection could be accurately controlled, it is feasible for application on electronics cooling. The developed micropump technology has been applied to wider fields. Thus, if the overall efficiency of micropump could be improved, the development of micropump could be enhanced. Therefore, this study discussed the use of micropump technology on cooling of heated surface, and the effect on refined micropump on overall injection and replenish efficiency. This study used CFD-RC commonly used in the micro-system field for analysis and simulation of the droplet injection speed, shape and path were simulated in the arrayed micropump. In the analysis of the droplet impacting the heated surfaced, the variables of fluid types, injection distance, droplet size, and hydrophile of the heated surface were analyzed by using CFD-RC to discuss the splash of the droplet when impacting the heated surface and the change of heat convection of the heated surface. The analysis of the refined micropump nozzle analyzed the droplet injection of different fluids and array effects. The results showed that as the hydrophile of heated surface improves (the contact angle decreases), the heated surface is more likely to disperse ethanol and the injection distance is larger. As the impacting force of the droplet on the heated surface increases, the droplet is more likely to splash on the heated surface, and is more effective in removing the surface heat. The refined nozzle is connected to coned channel and is affected by the channel, thus, the simulation results showed faster injection speed and better work fluid replenish efficiency than previous researches. The films shot with Schlieren show the evaporation of the droplet into gas upon impacting the heated surface. As for the refined micropump, in the simulation and experiment results, the shapes of the droplets were similar, and the injection speed of the convergent micropump【A】is 1m/s faster than that of divergent micropump【B】.

並列關鍵字

Thermal bubble arrayed micropump ； computational fluid dynamics ； micro droplet impact

參考文獻

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熱氣泡式微型泵浦之應用研究與模擬分析

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