Towards a Generalized SA Model: Symbolic Regression-Based Correction for Separated Flows

Fuente: arXiv
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Auteurs principaux: Sun, Xuxiang, Shan, Xianglin, Liu, Yilang, Zhang, Weiwei
Format: Preprint
Publié: 2025
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author Sun, Xuxiang
Shan, Xianglin
Liu, Yilang
Zhang, Weiwei
author_facet Sun, Xuxiang
Shan, Xianglin
Liu, Yilang
Zhang, Weiwei
contents This study focuses on the numerical simulation of high Reynolds number separated flows and proposes a data-driven approach to improve the predictive capability of the SA turbulence model. First, data assimilation was performed on two typical airfoils with high angle-of-attack separated flows to obtain a high-fidelity flow field dataset. Based on this dataset, a white-box model was developed using symbolic regression to modify the production term of the SA model. To validate the effectiveness of the modified model, multiple representative airfoils and wings, such as the SC1095 airfoil, DU91-W2-250 airfoil, and ONERA-M6 wing, were selected as test cases. A wide range of flow conditions was considered, including subsonic to transonic regimes, Reynolds numbers ranging from hundreds of thousands to tens of millions, and angles of attack varying from small to large. The results indicate that the modified model significantly improves the prediction accuracy of separated flows while maintaining the predictive capability for attached flows. It notably enhances the reproduction of separated vortex structures and flow separation locations, reducing the mean relative error in lift prediction at stall angles by 69.2% and improving computational accuracy by more than three times. Furthermore, validation using a zero-pressure-gradient flat plate case confirms the modified model's ability to accurately predict the turbulent boundary layer velocity profile and skin friction coefficient distribution. The findings of this study provide new insights and methodologies for the numerical simulation of high Reynolds number separated flows, contributing to more accurate modeling of complex flow phenomena in engineering applications.
format Preprint
id arxiv_https___arxiv_org_abs_2503_09225
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Towards a Generalized SA Model: Symbolic Regression-Based Correction for Separated Flows
Sun, Xuxiang
Shan, Xianglin
Liu, Yilang
Zhang, Weiwei
Fluid Dynamics
Computational Physics
This study focuses on the numerical simulation of high Reynolds number separated flows and proposes a data-driven approach to improve the predictive capability of the SA turbulence model. First, data assimilation was performed on two typical airfoils with high angle-of-attack separated flows to obtain a high-fidelity flow field dataset. Based on this dataset, a white-box model was developed using symbolic regression to modify the production term of the SA model. To validate the effectiveness of the modified model, multiple representative airfoils and wings, such as the SC1095 airfoil, DU91-W2-250 airfoil, and ONERA-M6 wing, were selected as test cases. A wide range of flow conditions was considered, including subsonic to transonic regimes, Reynolds numbers ranging from hundreds of thousands to tens of millions, and angles of attack varying from small to large. The results indicate that the modified model significantly improves the prediction accuracy of separated flows while maintaining the predictive capability for attached flows. It notably enhances the reproduction of separated vortex structures and flow separation locations, reducing the mean relative error in lift prediction at stall angles by 69.2% and improving computational accuracy by more than three times. Furthermore, validation using a zero-pressure-gradient flat plate case confirms the modified model's ability to accurately predict the turbulent boundary layer velocity profile and skin friction coefficient distribution. The findings of this study provide new insights and methodologies for the numerical simulation of high Reynolds number separated flows, contributing to more accurate modeling of complex flow phenomena in engineering applications.
title Towards a Generalized SA Model: Symbolic Regression-Based Correction for Separated Flows
topic Fluid Dynamics
Computational Physics
url https://arxiv.org/abs/2503.09225