A dynamic immersed boundary method for simulating an adaptive nozzle generating discrete wind gusts
Publication date
2025-08-06
Document type
Forschungsartikel
Organisational unit
Publisher
Elsevier Science
Series or journal
Computers & Fluids
ISSN
Periodical volume
301
Article ID
106775
Peer-reviewed
✅
Part of the university bibliography
✅
Language
English
DDC Class
000 Informatik, Information & Wissen, allgemeine Werke
500 Naturwissenschaften
600 Technik
Keyword
Horizontal wind gusts
Numerical wind tunnel
Immersed boundary method
Moving-least-squares
Large-eddy simulation
Fluid–structure interaction
Abstract
The recently developed wind gust generator, the adaptive nozzle (Wood and Breuer, 2025) , features a nozzle
with a fully rotatable upper contour, enabling a smooth gust generation with low unwanted flow disturbances.
While preserving the underlying gust-generation principle of its predecessor, the new design significantly
reduces pressure losses caused by flow blockage and preserves the original horizontal trajectory of the flow
along the streamwise direction. While experiments have validated the improved design, a comprehensive
numerical analysis is crucial to resolve the three-dimensional flow fields across the entire computational
domain. This shall also facilitate capturing the resulting transient aerodynamic loads on a wind tunnel specimen
— quantities difficult to measure experimentally. To accurately capture the complex flow dynamics, high-
fidelity large-eddy simulations are conducted, modeling the nozzle’s upper contour as a dynamic immersed
boundary (IB). A curvilinear Eulerian grid is employed to ensure both efficient and precise spatial resolution
of the problem. The moving least-squares (MLS) version of the direct forcing IB approach (Vanella and Balaras,
2009) is used to construct an IB kernel for each Lagrangian marker. Additionally, the MLS approach is also
applied to construct one-sided kernel functions for Lagrangian points near the boundaries of the computational
domain. Challenges related to the efficient IB simulation on curvilinear grids are addressed, and a solution is
proposed within the MLS framework. The predicted results are analyzed in detail and validated against the
experimental data by Wood and Breuer (2025) , providing insights into the effectiveness of the new design in
generating controlled wind gusts.
with a fully rotatable upper contour, enabling a smooth gust generation with low unwanted flow disturbances.
While preserving the underlying gust-generation principle of its predecessor, the new design significantly
reduces pressure losses caused by flow blockage and preserves the original horizontal trajectory of the flow
along the streamwise direction. While experiments have validated the improved design, a comprehensive
numerical analysis is crucial to resolve the three-dimensional flow fields across the entire computational
domain. This shall also facilitate capturing the resulting transient aerodynamic loads on a wind tunnel specimen
— quantities difficult to measure experimentally. To accurately capture the complex flow dynamics, high-
fidelity large-eddy simulations are conducted, modeling the nozzle’s upper contour as a dynamic immersed
boundary (IB). A curvilinear Eulerian grid is employed to ensure both efficient and precise spatial resolution
of the problem. The moving least-squares (MLS) version of the direct forcing IB approach (Vanella and Balaras,
2009) is used to construct an IB kernel for each Lagrangian marker. Additionally, the MLS approach is also
applied to construct one-sided kernel functions for Lagrangian points near the boundaries of the computational
domain. Challenges related to the efficient IB simulation on curvilinear grids are addressed, and a solution is
proposed within the MLS framework. The predicted results are analyzed in detail and validated against the
experimental data by Wood and Breuer (2025) , providing insights into the effectiveness of the new design in
generating controlled wind gusts.
Cite as
Computers & Fluids Volume 301, 2025, 106775
Version
Published version
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