Wind Gusts and their Dynamic Effects on Flexible Structures: Modeling and High-Resolution Simulations

• Applicant: Professor Dr.-Ing. Michael Breuer
• Subject Area: Fluid Mechanics
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 435252632

• Final Report Year: 2024

Final Report Abstract

The objective of the present project was to develop a methodology to efficiently simulate and analyze the effect of strong turbulent wind gusts on flexible lightweight structures. For the design and dimensioning of these constructions the highly dynamic interaction between rather rare but very strong gusts and the structure is the crucial factor that decides on structural safety and stability. Compared to these extreme loads, flows described by standard atmospheric turbulent boundary layers are of little relevance for the dimensioning, robustness and durability. For the latter scenario huge efforts have been made in the past years for developing coupled fluid-structure interaction (FSI) simulation tools allowing to investigate the interaction of flexible structures with turbulent flows. However, the load case where wind gusts hit a flexible structure leading to extreme loads has been considered only to a small extent in the literature so far. Thus, the objective of the proposal was to close this gap by developing a simulation strategy which allows to tackle such coupled and highly dynamic physical processes in an efficient manner. For this purpose, four different gust modeling techniques were analyzed/developed and extensively tested using various application scenarios from aeronautics and civil engineering, including vertical and horizontal wind gusts. As a result, it is even possible to determine the worst-case scenario.

Publications

• A source-term formulation for injecting wind gusts in CFD simulations. Journal of Wind Engineering and Industrial Aerodynamics, 207, 104405.
  De Nayer, G. & Breuer, M.
  
• Assessment of two wind gust injection methods: Field velocity vs. split velocity method. Journal of Wind Engineering and Industrial Aerodynamics, 218, 104790.
  Boulbrachene, Khaled; De Nayer, Guillaume & Breuer, Michael
  
• Injection of wind gusts in large-eddy simulations, 13th Int. ERCOFTAC Symposium on Engineering, Turbulence, Modelling and Measurements: ETMM-13, Rhodes, Italy, Sept. 15–17, 2021. Online presentation, (no paper).
  De Nayer, G. & Breuer, M.:
  
• Assessment of discrete wind gust parameters: Towards the worst-case scenario of a FSI application in form of an inflated hemisphere. Journal of Wind Engineering and Industrial Aerodynamics, 231, 105207.
  De Nayer, G. & Breuer, M.
  
• FSI simulations of wind gusts impacting an air-inflated flexible membrane at Re = 100,000. Journal of Fluids and Structures, 109, 103462.
  De Nayer, G.; Breuer, M. & Boulbrachene, K.
  
• Aeroelastic response of an elastically mounted 2-DOF airfoil and its gust-induced oscillations. Journal of Fluids and Structures, 117, 103828.
  Boulbrachene, K. & Breuer, M.
  
• Surrogate-based optimization for the worst-case prediction regarding a flexible structure impacted by wind gusts. Journal of Wind Engineering and Industrial Aerodynamics, 243, 105610.
  De Nayer, G. & Breuer, M.
  
• Wind gust–induced flutter of an elastically mounted airfoil: A fluid– structure interaction study based on LES, 13th Int. ERCOFTAC Workshop on DNS and LES: DLES-13, Udine, Italy, Oct. 26–29, 2022. ERCOFTAC Series, vol. 31, Direct and Large–Eddy Simulation XIII, eds. C. Marchioli et al., ISBN 978–3–031–47027–1, Springer Nature Switzerland AG, (2024).
  Boulbrachene, K. & Breuer, M.