水下固体壁面湍流边界层流场测试方法

基于热线测速技术，研究了水下固体壁面湍流边界层流场的精确测试方法，并从稳定低速流实现、探针杆密封及探针测距等方面给出了提高测试水平的可行措施.搭建起一套重力式低速水槽系统，实现了0~1.0 m/s水速范围内连续可调的稳定流场，其中心湍流度低于2.5%；采用探针杆密封滑筒和双组密封套等部件，实现3 m水头下的动密封；基于光学经纬仪角度测量原理，总结出一种微距的精确测量方法，其测量误差小于0.3%；采用普朗特 尼库拉兹公式计算摩擦系数，替代了壁面摩擦系数的实验测量.测试结果表明，该套测试方法能准确测得水下湍流边界层的流场分布，具备用于水下固体壁面边界层流场测试的能力.

Turbulent Boundary Layer Testing Technique over a Solid Surface under Water

Based on the hot wire anemometry system, an experiment for turbulent boundary layer testing technique over a solid surface under water was conducted. Several feasible methods for improvement of testing were provided, such as realization of stable low speed flow, pressurization of water probe and the distance measurement between probe and solid surface, etc. A gravitational low speed flume system was designed, which could realize continuous water flow of 0 to 1.0 m/s, and the turbulent intensity was no more than 2.5%. The pressurization under 3m waterhead was obtained by using the probe pole and two-layer pressurization cushion. Based on the angle measurement of an optical theodolite, a length measurement method was acquired whose measuring error was less than 0.3%. In place of experimental measurement, the friction coefficient was calculated using the Prantl-Nikuradse experiential equation. The results indicate that this technique is capable of measuring turbulent boundary layer over a solid surface under water precisely.