On the wake flow of asymmetrically beveled trailing edges

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• 作者：Yaoyi Guan ; Stefan Pröbsting ; David Stephens ; Abhineet Gupta…
• 刊名：Experiments in Fluids
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：57
• 期：5
• 全文大小：7,299 KB
• 刊物类别：Engineering
• 刊物主题：Engineering Fluid Dynamics
  Fluids
  Industrial Chemistry and Chemical Engineering
  Measurement Science and Instrumentation
  Thermodynamics
  Theoretical and Applied Mechanics
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1432-1114
• 卷排序：57

文摘

Trailing edge and wake flows are of interest for a wide range of applications. Small changes in the design of asymmetrically beveled or semi-rounded trailing edges can result in significant difference in flow features which are relevant for the aerodynamic performance, flow-induced structural vibration and aerodynamically generated sound. The present study describes in detail the flow field characteristics around a family of asymmetrically beveled trailing edges with an enclosed trailing-edge angle of \(25^\circ\) and variable radius of curvature R. The flow fields over the beveled trailing edges are described using data obtained by particle image velocimetry (PIV) experiments. The flow topology for different trailing edges was found to be strongly dependent on the radius of curvature R, with flow separation occurring further downstream as R increases. This variation in the location of flow separation influences the aerodynamic force coefficients, which were evaluated from the PIV data using a control volume approach. Two-point correlations of the in-plane velocity components are considered to assess the structure in the flow field. The analysis shows large-scale coherent motions in the far wake, which are associated with vortex shedding. The wake thickness parameter \(y_{f}\) is confirmed as an appropriate length scale to characterize this large-scale roll-up motion in the wake. The development in the very near wake was found to be critically dependent on R. In addition, high-speed PIV measurements provide insight into the spectral characteristics of the turbulent fluctuations. Based on the time-resolved flow field data, the frequency range associated with the shedding of coherent vortex pairs in the wake is identified. By means of time-correlation of the velocity components, turbulent structures are found to convect from the attached or separated shear layers without distinct separation point into the wake.