報告題目：Computing the finite time Lyapunov exponent for flows with uncertainties

報告人：   尤國橋，南京審計大學，教授

報告時間：2023年11月3日下午16：15

報告地點：江甯校區勵學樓B219

報告摘要：We propose an Eulerian approach to compute the expected finite time Lyapunov exponent (FTLE) of uncertain flow fields. The definition extends the usual FTLE for deterministic dynamical systems. Instead of performing Monte Carlo simulations as in typical Lagrangian computations, our approach associates each initial flow particle with a probability density function (PDF) which satisfies an advection-diffusion equation known as the Fokker-Planck (FP) equation. Numerically, we incorporate Strang’s splitting scheme so that we can obtain a second-order accurate solution to the equation. To further improve the computational efficiency, we develop an adaptive approach to concentrate the computation of the FTLE near the ridge, where the so-called Lagrangian coherent structure (LCS) might exist. We will apply our proposed algorithm to several test examples including a real-life dataset to demonstrate the performance of the method.

報告人簡介：尤國橋，南京審計大學伟德国际1946官网教授、應用數學系主任，江蘇省計算數學分會常務理事，江蘇省工業與應用數學學會理事。入選江蘇省高校“青藍工程”優秀青年骨幹教師、江蘇省“雙創博士”，獲得第三屆南京審計大學“青年五四獎章”。主要研究方向為複雜問題的可計算建模與數值模拟、流場可視化。主要研究結果發表在SIAM J. Sci. Comput.、J. Comput. Phys.、 J. Sci. Comput.等計算數學領域國際知名期刊上。主持國家自然科學基金面上項目和青年項目、江蘇省自然科學基金面上項目和青年項目等課題。