Numerical simulation of discrete wind gusts generated by an adaptive nozzle using a dynamic immersed boundary method
Publication date
2026-05-01
Document type
Konferenzbeitrag
Organisational unit
Conference
5th International Conference on Computational Engineering (ICCE 2024) ; Darmstadt, Germany ; September 30 – October 2, 2024
Publisher
Springer
Series or journal
Lecture Notes in Computational Science and Engineering
Periodical volume
150
Book title
New Trends in Computational Engineering
First page
37
Last page
51
Peer-reviewed
✅
Part of the university bibliography
✅
Language
English
DDC Class
000 Informatik, Information & Wissen, allgemeine Werke
500 Naturwissenschaften
600 Technik
Keyword
wind gusts
CFD
Immersed boundary method
LES
dtec.bw
Abstract
A wind gust is a short-term but strong phenomenon naturally appearing in the atmospheric boundary layer. Fluid-structure interaction investigations under wind gust conditions, ideally in a wind tunnel with controlled parameters, are essential for evaluating the safety of final designs for example in civil engineering. For this purpose, Wood et al. (J Wind Eng Ind Aerodyn 230:105170, 2022) developed a novel wind gust generator denoted the “Paddle”. Its basic principle relies on the partial dynamic blocking of the wind tunnel nozzle’s outlet by a vertically moving plate that penetrates the free-stream. The setup and the flow induced by the paddle were numerically simulated in Boulbrachene and Breuer (Phys Fluids 36:015146, 2024) by employing an immersed boundary method (IBM) relying on a direct forcing approach to mimic the motion of the paddle. This configuration restricted the undisturbed gust region in the test section of the wind tunnel as a result of the shear layer forming at the lower edge of the moving paddle. Moreover, it caused an undershoot of the gust velocity below the free-stream velocity as a result of high pressure losses associated with the paddle’s blockage effect. Wood and Breuer (Artificial wind gust generation based on an adaptive nozzle design. Berlin, pp 9-1–9-8, 2024) and Wood and Breuer (J Wind Eng Ind Aerodyn 261:106080, 2025) recently introduced an improved design that addresses the shortcomings of the paddle while maintaining the same underlying principle for generating the gust. The new setup features an adjustable nozzle with a fully rotatable upper contour to generate smoother wind gusts. In order to gain a comprehensive understanding of the evolving flow field during the movement of the nozzle’s upper boundary, large-eddy simulations of the process are conducted. This involves modeling the nozzle’s upper boundary as a moving immersed boundary using again the IBM with direct forcing but this time on a curvilinear Eulerian grid. The numerical methodology and its application to the movable nozzle case is presented in the present study. The predicted results are analyzed in detail and compared with available experimental measurement data (Wood and Breuer in Artificial wind gust generation based on an adaptive nozzle design. Berlin, pp 9-1–9-8, 2024) and (Wood and Breuer in J Wind Eng Ind Aerodyn 261:106080, 2025).
Cite as
LNCS 2026 150, 37-51
Version
Published version
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