Simultaneous flow measurement and deformation tracking for passive flow control experiments involving fluid-structure interactions

作     者：Koesters, Wolf Iring Hoerner, Stefan 

作者机构：Otto von Guericke Univ Magdeburg OvGU Inst Fluid Dynam & Thermodynam Lab Fluid Dynam & Tech Flows Univ Pl 2 D-39106 Magdeburg Germany Tallinn Univ Technol Taltech Ctr Biorobot Akad Tee 15A EE-12616 Tallinn Estonia 

出 版 物：《JOURNAL OF FLUIDS AND STRUCTURES》 (流体与结构杂志)

年 卷 期：2023年第121卷第1期

核心收录：

学科分类：080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 

基　　金：European Union 

主　　题：Fluid-structure interaction Deformation tracking PIV Masking NACA0018 hydrofoil Passive flow control 

摘      要：Fluid-structure interactions (FSI) on highly flexible structures involve large deformations and require specific techniques for a thorough investigation of the flow field and structural deformation. To this purpose, a physics-informed method is introduced that allows for simultaneous determination of the flow fields and the structural deformation by using Particle Image Velocimetry (PIV) raw images. The method combines apriori knowledge of the mechanical characteristics of the flexible structure with classical image processing techniques for segmentation. PIV recordings of an actively pitched, highly deformable hydrodynamic profile experiment in a closed water tunnel serve as an example case. To achieve accurate results, the contour obtained from image segmentation is further defined under the assumption that its flexure can be described with the Euler-Bernoulli beam theory model. This makes it possible to determine the neutral fiber of the structure and the final reconstruction becomes possible from knowledge of the original geometry. The resulting procedure allows for a recognition of the structure itself and is suitable for cross-section deformation measurements and for masking of the structure in the raw images to improve the PIV processing. A test case comprising synthetic data similar to the application with a modeled profile geometry of known shape is used to investigate the accuracy of the method and its validity for deformation measurements. Under conditions of cyclic dynamic stall, a mean absolute error of 0.84 could be reached, with a deterioration up to 2 mean absolute error under static stall. The method has a major advantage compared to other technically more sophisticated and complex methods, such as the combination of Laser interferometers combined with Laser-Doppler Anemometry: the method allows for the usage of a single data source for both, fluid and solid in a unified measurement method. Therefore a direct comparison of instantaneous