边界层人工转捩的壁面脉动压力特性试验研究

Experimental study on wall pressure fluctuation characteristic of boundary layer artificial transition

为了研究边界层人工转捩装置上下游的壁面脉动压力功率谱特征,验证边界层人工转捩装置在实现模型载荷相似方面的有效性,并进一步指导绊线及粗糙元的几何与尺寸设计。通过水下航行体缩尺模型的壁面脉动压力测试,测量并对比分析了4种绊线和粗糙元上下游边界层的壁面脉动压力自功率谱。结果表明:绊线和粗糙元下游的壁面脉动压力自功率谱平台区谱级高于上游;相同流速下,绊线下游壁面脉动压力自功率谱平台区谱级与绊线及高度密切相关。中低流速下绊线下游人工转捩边界层可与高流速下平板自然转捩边界层壁面脉动压力自功率谱平台区谱级相当,即绊线明显削弱了壁面脉动压力载荷的尺度效应。

In order to study the wall pressure fluctuation spectra characteristics up and downstream the boundary layer artificial transition devices and to verify the validity of boundary layer artificial transition devices in model test load similarity,furthermore,to guide the geometry and size design of trips and roughness elements.Based on scaled underwater vehicle model wall fluctuating pressure test,the wall pressure fluctuation auto-spectra up and downstream 4 kinds of trips and roughness elements were measured and contrastively analysed.The results show that:the flat zone magnitude of the wall pressure fluctuation auto-spectra downstream trips and roughness elements were higher than upstream ones;in similar speed,the flat zone altitudes of the wall pressure fluctuation auto-spectra are mainly related to the height of the trips,the flat zone magnitude of the wall pressure fluctuation auto-spectra of the artificial transition boundary layer downstream trips in lower speed could be equivalent to their plate natural transition boundary layer counterpart in higher speed,which indicates that trips could evidently alleviate the scale effect of wall pressure fluctuation load.