Distributed force element decomposition with method of fundamental solutions

Fuente: arXiv
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Main Authors: Zhou, Zhiteng, Liu, Yi, Wang, Hongping, Wang, Shizhao
Format: Preprint
Published: 2025
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_version_ 1866916949538111488
author Zhou, Zhiteng
Liu, Yi
Wang, Hongping
Wang, Shizhao
author_facet Zhou, Zhiteng
Liu, Yi
Wang, Hongping
Wang, Shizhao
contents Quantifying the contribution of vortex structures to pressure stress is useful for designing flow control strategies to mitigate low or drag. The traditional force-element method focuses on the contribution of vortex structures to the resultant force. However, the contribution of vortex structures to the distributed force can not be identified. To address this problem, a distributed force element method is proposed. This method projects the Navier-Stokes equation to a divergence-free space and obtain a Poisson equation for pressure. The Green's function is employed to express pressure stress on the solid boundary as a combination of volume and surface integrals. Contributions to the distributed source are divided into acceleration surface elements, vorticity surface elements, convection volume elements. The method of fundamental solutions and singular value decomposition are used to efficiently solve the Green's functions. The distributed force element method is validated using laminar flows around a stationary circular cylinder and oscillating circular cylinder, and three-dimensional laminar and turbulent flows around a sphere. In laminar flow over a circular cylinder, fluctuation of forces mainly originate from volume sources, while in flow over an oscillating circular cylinder, inertial and volume source terms may cancel out, suppressing lift fluctuation. In flows over a sphere, a strong negative volume source in the boundary layer on the sphere creates low-pressure regions, while pressure in the separated shear layer is close to zero.
format Preprint
id arxiv_https___arxiv_org_abs_2509_07783
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Distributed force element decomposition with method of fundamental solutions
Zhou, Zhiteng
Liu, Yi
Wang, Hongping
Wang, Shizhao
Fluid Dynamics
Quantifying the contribution of vortex structures to pressure stress is useful for designing flow control strategies to mitigate low or drag. The traditional force-element method focuses on the contribution of vortex structures to the resultant force. However, the contribution of vortex structures to the distributed force can not be identified. To address this problem, a distributed force element method is proposed. This method projects the Navier-Stokes equation to a divergence-free space and obtain a Poisson equation for pressure. The Green's function is employed to express pressure stress on the solid boundary as a combination of volume and surface integrals. Contributions to the distributed source are divided into acceleration surface elements, vorticity surface elements, convection volume elements. The method of fundamental solutions and singular value decomposition are used to efficiently solve the Green's functions. The distributed force element method is validated using laminar flows around a stationary circular cylinder and oscillating circular cylinder, and three-dimensional laminar and turbulent flows around a sphere. In laminar flow over a circular cylinder, fluctuation of forces mainly originate from volume sources, while in flow over an oscillating circular cylinder, inertial and volume source terms may cancel out, suppressing lift fluctuation. In flows over a sphere, a strong negative volume source in the boundary layer on the sphere creates low-pressure regions, while pressure in the separated shear layer is close to zero.
title Distributed force element decomposition with method of fundamental solutions
topic Fluid Dynamics
url https://arxiv.org/abs/2509.07783