數值模擬運用結構法則來強化太陽花散熱鰭片效能

Numerical simulation of the use of constructal law to intensification the effectiveness of sunflowers fin

陳煒杰(Wei-Chieh Chen)

指導教授 ： 李世鳴

淡江大學/工學院/航空太空工程學系碩士班/碩士(2015年)

https://doi.org/10.6846/TKU.2015.00061

摘要

本研究依據Adrian Bejan所著作的Design with Constructal Theory，改變太陽花散熱鰭片結構外型，探討不同結構外型的散熱鰭片對於熱傳特性的影響。維持太陽花散熱鰭片的總表面積，改變其苗條度、鰭片的分叉數量、無因次化參數D ̃以及無因次化參數R ̃，並且運用數值模擬分析改變鰭片結構對於熱阻的變化。散熱鰭片使用的材料為鋁；發熱源使用的材料為銅，熱源給予固定瓦數加熱。給定固定風速使用強制對流的方式散熱。考慮K-epsilon紊流模型以及能量方程式，數值求解方法中壓力-速度耦合使用Coupled Solver求解，壓力離散項採用PRESTO!，動量與能量方程採用QUICK離散格式，紊流消散率以及紊流動能採用二階上風算則。數值模擬計算結果與Design with Constructal Theory文中的理論比較，模擬分析顯示改變其苗條度、鰭片的分叉數量、D ̃以及R ̃確實對於太陽花散熱鰭片的熱阻有所影響，發現提高分叉數量、將D ̃以及R ̃的比值提高能減少散熱鰭片的熱阻，將苗條度降低也能使散熱鰭片的熱阻減少。

關鍵字

太陽花散熱鰭片 ； Constructal Theory ； 結構法則 ； 苗條度

並列摘要

This study is based on the writings of Adrian Bejan Design with Constructal Theory, changing the shape of sunflowers fin. Investigate different shape of fins for heat transfer characteristics. Maintain the total surface area of sunflowers fin and changes its Svelteness, the numbers of bifurcated fins, dimensionless parameters D and R, and use numerical simulation to analyze the influence of changes the structure of fins for the thermal resistance. The heat source is heated by fixed wattage. Using force convection for cooling. The numerical simulation results compare with theory, the analysis shows that changes the Svelteness, the number of bifurcated fin, dimensionless parameters D and R indeed influence the thermal resistance, increasing the number of bifurcated fins, the values of dimensionless parameters D and R can be reduced the thermal resistance, and decrease the value of Svelteness also can be reduced the thermal resistance.

並列關鍵字

Sunflowers fin ； Constructal Theory ； Svelteness

參考文獻

[1] Design with Constructal Theory

John Wiley & Sons, Inc.

[2] M. Almogbel, A. Bejan

“Cylindrical trees of pin fins”, International Journal of Heat and Mass Transfer

Volume 43, Issue 23, 1 December 2000, Pages 4285–4297