摘 要：3ω法已成功應(yīng)用于體態(tài)、薄膜等材料導(dǎo)熱系數(shù)的測量，但還很少應(yīng)用于流體領(lǐng)域。由于3ω法具有良好的測試性能，為此嘗試將此法用于流體導(dǎo)熱系數(shù)的測量。自行研制了流體導(dǎo)熱系數(shù)的測量裝置，采用鎖相放大器獲取3ω電壓與頻率的關(guān)系，并借助最小二乘法，算出待測試樣的導(dǎo)熱系數(shù)。通過對10＃變壓器油和去離子水等流體試樣的測量，實驗誤差控制在5％之內(nèi)，表明本實驗具有一定的可行性。
關(guān)鍵詞：3ω法；流體；導(dǎo)熱系數(shù)；溫度振動
中圖分類號：TB941 文獻標識碼：A 文章編號：1672-4984（2007）04-0001-04
Thermal conductivity of fluids measured with 3ω method
GE Shu-lin， YANG Jue-kuan， CHEN Zhen， CHEN Min-hua， CHEN Yun-fei
（School of Mechanical Engineering，Key Laboratory of Educational Ministry，Southeast University，Nanjing 211189，China）
Abstract: While successfully used in measuring the thermal properties of solid material, such as bulk samples and thin films， 3ω method is seldom applied to the fluid. Due to its good performance， the 3ω method is tried to measure the thermal conductivity of the fluid in this paper. Using the home made device， the relationship between the 3ω voltage and the heating frequency is obtained by Lock-in Amplifier， thus the thermal conductivity of the fluid is calculated with the least square fit method. From the results of 10# transformer oil and deionized water， the error is limited to 5%， which indicates the definite feasibility of the experiment.
Key words: 3ω voltage； Fluid； Thermal conductivity； Temperature fluctuation
