温度场内尺度估算方法的研究
Study of estimating inner-scale of temperature field
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摘要:用三维超声风速计测量了合肥地区风速脉动和温度脉动数据, 从Kolmogorov的4/5定律估算湍流动能耗散率\varepsilon, 从Yaglom的4/3定律估算温度方差耗散率\varepsilon _\theta, 指出现有文献提供的公式不适合计算温度场的内尺度. 提出了一种温度场内尺度计算公式, 式中含有温度方差耗散率\varepsilon_\theta , 得到的内尺度大小正确反映了与C_n^2 强弱的对应关系.Abstract:The three velocity components and air temperature weremeasured using a triaxial ultrasonic anemometer in Hefei region of China.The mean dissipation rates of turbulent kinetic energy \varepsilon and1/2 temperature variance \varepsilon _\theta have been estimated byKolmogorov's `four-fifths' law and Yaglom's `four-thirds' law, respectively.It is pointed that the traditional method is not suitable for estimatinginner scale of temperature field. A new relation between the inner scale oftemperature field and 1/2 temperature variance \varepsilon _\theta ispresented. The results of estimating inner scale by the new proposed methodperfectly show that strong turbulence has small inner scales and weakturbulence larger inner scales.