本研究透過數值模擬研究線狀電極電液動(EHD,Electrohydrodynamic)技術應用於自然對流的熱增強及最佳化分析。以二維紊流模型探討三種自然對流系統：側邊加熱之封閉矩形(case A)、底部加熱之封閉矩形(case B)和底部加熱之無限長水平板(case C)，在不同施加電壓、溫差、電極高度及電極數(電極間距)下，電液動所產生的熱增強效果，並考慮焦耳熱效應對溫度場及熱傳增強的影響。
在側邊加熱(case A)及底部加熱(case B)之封閉矩形中，增加施加電壓可以有效提升熱傳增益；當電極數(N=1-6)增加時，會造成流場中的渦流數增加和電極產生的焦耳熱效應增強；隨電極高度(HEHD=10-40mm)改變，當電極高度位在右半部(上半部)會有最大紐賽數比。由於EHD為主動式熱增強方式，因而需考慮施加的功率Power並定義單位功耗之淨熱傳增強量(QEHD-Q0)/Power作為衡量熱增強效率的標準。在特定的施加電壓V0 (12、13和14kV)及溫差∆T (20、25和30K)下，透過參數分析可以得到最佳(QEHD-Q0)/Power及其對應的電極數(N)和電極高度(HEHD)組合。
在底部加熱之水平無限長平板(case C)中，增加施加電壓可以有效提升熱傳增益；隨電極間距或電極高度改變，紐賽數比存在最佳值。在熱增強的最佳化研究中，利用簡易共軛梯度法執行最佳化搜尋，並以(QEHD-Q0)/Power為目標函數，藉由電極高度(HEHD)和電極間距(SL)的變化，搜尋目標函數的最大值，其搜尋範圍分別為10mm < HEHD < 40mm和50mm < SL < 90mm。結果顯示，在特定施加電壓V0 (12、13和14kV)及溫差∆T (20、25和30K)下，可以得到最佳(QEHD-Q0)/Power及其對應的電極高度(HEHD)和電極間距(SL)組合。

The paper studied the wire electrodes EHD effect on the heat transfer enhancement by numerical method. There were three type of physical models, enclosure heat from side (case A), enclosure heated from below (case B) and infinite horizontal plates heated from below (case C). Two-dimensional turbulent models for the prediction of heat transfer enhancement with different applied voltage, number of electrodes, electrode pitch and electrode height were investigated and evaluated the effects of Joule heating on heat transfer performance. The result shows that the heat transfer enhancement increases as the applied voltage increases. The number of vortices in the flow field increases with the increase in number of electrodes. Furthermore, the power consumption was also taken into account, and the net heat transfer enhancement per unit power consumption (QEHD-Q0)/Power was taken as the objective function. The maximum objective function value and the optimal electrode arrangement were obtained with specified V0 (12, 13 and 14 kV) and specified ∆T (20, 25 and 30 K) by numerical analysis or optimal strategy (SCGM, simplified conjugate gradient method).

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