An accurate vortex feature extraction method for Lagrangian vortex visualization on high-order flow field data

作者：Wang, Fang^*; Zhao, Dan; Deng, Liang; Li, Sikun

来源：Journal of Visualization, 2017, 20(4): 729-742.

DOI：10.1007/s12650-017-0421-y

• Scientific visualization
• Vortex feature extraction
• Unsteady flow field
• Coherent Lagrangian vortex

As vortex is of great significance to structure analysis and mechanism research in flow field, vortex feature extraction has always been a hot research topic in flow field visualization. We investigate the data precision and numerical algorithm accuracy impact on vortex feature area extraction of Lagrangian Averaged Vorticity Deviation (LAVD). Then, an LAVD-based high-order accurate vortex extraction algorithm is proposed, which incorporates vorticity computation of cell-vertexed data by Weighted Essentially Non-Oscillatory (WENO) scheme, vorticity and velocity computation of off-grid point by candidate stencil weight-based high-order polynomial interpolation method, flow map computation by 4th-order Runge-Kutta (RK) method and integration by compound Simpson rule. We perform vortex feature extraction and visualization on both analytical flow field and high-order unsteady flow field. The experiment results demonstrate that the proposed algorithm can practically reflect the vortex feature of high-order flow field and accurately describe small scale vortex structure, which is unavailable by low-order method.

• 出版日期2017-11
• 单位中国空气动力研究与发展中心; 中国人民解放军国防科学技术大学