基于Mu-leval法的湍流猝发频率检测技巧研究

条件采样技术是目前最成熟、使用最广的湍流猝发频率检测方法，其中的Mu-level法以其原理简单、门限无关区域宽等优点，长期被湍流研究者所使用。针对Mu-level法分析结果易受试验及检测参数影响的问题，论文详细探讨了该方法用于湍流猝发频率检测的适应性和提高其检测精度的技巧。文中所用湍流流场数据是由配备单直丝探头的IFA300恒温热线风速仪在某小型专用风洞试验段中心截面处测量获得。通过对不同法向检测位置、采样频率、采样时间、门限值L及附加判定条件下湍流猝发频率的检测和对比分析，获取了各因素对湍流猝发频率检测的影响规律，探讨了提高湍流猝发频率检测准确性的可行途径，并总结了一套基于Mu-leval法的湍流猝发频率四步测试方法（试采样、试分析、采样、检测分析）。

Research about the Techniques of Burst Detection in Turbulent Boundary Layer with the Mu-leval Algorithm

Conditional sampling techniques are the most mature and extensive measures of burst-detection in turbulent boundary layer. The Mu-leval algorithm is one of algorithms adopted always by researcher, which is simple and insensitive to the detecting parameters. In allusion to the analysis results with the Mu-leval algorithm are influenced easily by measure and detection parameters, the adaptability of burst-detection in turbulent boundary layer are researched detailedly. The measure dates are acquired in a center section of a small special win tunnel using IFA300 hot-wire anemometer with a single hot-wire sensor probe. Through the contrastive analysis of vertical testing position, sampling frequency, sampling time, boundary-parameter and accessional determinant condition, influence rules of above factor to burst-detection are acquired, and feasible approaches to enhance burst frequency veracity in turbulent boundary layer are discussed, finally a four-step method detecting burst frequency with Mu-leval algorithm (fore-sampling, fore-analysis, sampling, detection analysis) is summarized.