尾流温度场对其速度场的影响与加热减阻

本文利用LDV—02型激光测速仪,在循环水槽里测量了加热和非加热流线型细长旋成体尾流的速度分布和湍流度,并把Hama&Peterson的半经验理论(它适用于非加热体的类似尾流)修正为本文的半经验分析,较好地描述了尾流温度场对其速度场的影响,还从测得的尾流速度数据推断出加热对水下运动物体阻力系数的影响。

Influence of Temperature Field of Wake Flow on its Velocity Field and Drag Reduction by Heating

With the aid of the LDV-02 laser velocimeter, we measured the mean velocity, turbulence level and radius of the wake flow behind a slender streamlined body of revolution under heating or non-heating conditions, the body supported in a recirculating water channel. The measurements were made at the body-diameter Reynolds number 2400 in the region extending from four-body diameters to sixteenbody diameters downstream. The semi-empirical theory of Hama and Peterson(Ref. [1]), which was developed for the calculation of a simitar wake behind the non-heated body, is modified to handle the present cases with heat transfer effects between the heated body and its wake flow. Therefore, modification to the semi-empirical analysis in Ref. [1] is made to describe how temperature field of the wake influences its velocity field. Information concerning the influence of heating on drag coefficient of the body is inferred from the wake centerline velocity.