水-聚丙醯胺黏彈性流體之黏滯係數與熱傳導係數量測

Abstract

本文主要是在量測水-聚丙醯胺黏彈性流體的黏滯係數與熱傳導係數，並對不同的水溶液濃度、溫度及剪切率作探討，以求出其所對應的關係式。實驗結果發現，當流體溫度及剪切率上升時，聚丙醯胺水溶液的黏滯係數會隨之下降，而熱傳導係數則隨之上升。此外，當水溶液的濃度較高時，其輕剪力流體特性較明顯，且黏滯係數較高，但熱傳導係數較低；當濃度降低時，則輕剪力流體特性較不明顯，黏滯係數較低，但熱傳導係數較高。因此若要將聚丙醯胺水溶液使用於熱傳增強上，又不欲增加流動時的壓力差降，應使用濃度較低的聚丙醯胺水溶液。

In this thesis, the viscosity and the thermal conductivity of viscoelastic water-polyacrylamide fluids were investigated experimentally by examining the effects of polymer concentration, fluid temperature and shear rate. Present results showed that when fluid temperature and shear rate increased, the viscosity would decline and the thermal conductivity would rise. Moreover, the viscoelastic water-polyacrylamide fluid at higher polymer concentration showed the shear thinning characteristics with higher viscosity and lower thermal conductivity. On the contrary, the viscoelastic water-polyacrylamide fluid at low polymer concentrations showed the Newtonian fluid properties with lower viscosity and higher thermal conductivity. As a result, it is suggested that lower concentration viscoelastic water-polyacrylamide fluids would be beneficial to obtain better heat enhance practical applications and lower pressure drop in some.