摘  要：3ω法已成功应用于体态、薄膜等材料导热系数的测量，但还很少应用于流体领域。由于3ω法具有良好的测试性能，为此尝试将此法用于流体导热系数的测量。自行研制了流体导热系数的测量装置，采用锁相放大器获取3ω电压与频率的关系，并借助最小二乘法，算出待测试样的导热系数。通过对10＃变压器油和去离子水等流体试样的测量，实验误差控制在5％之内，表明本实验具有一定的可行性。   关键词：3ω法；流体；导热系数；温度振动   中图分类号：TB941  文献标识码：A   文章编号：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