应土木工程学院陈文礼教授邀请，美国莱特州立大学（Wright State University）机械与材料工程系杨自丰教授将于2026年7月16日至18日访问我校并作三场学术报告，欢迎相关专业师生参加。

报告安排

报告摘要一

Intracranial aneurysm (IA) is a life-threatening cerebrovascular disorder whose rupture can cause severe subarachnoid hemorrhage, with high mortality and disability rates. The presence of a bleb on an aneurysm is regarded as a morphological marker of elevated rupture risk; however, the mechanisms of bleb formation and reliable rupture prediction remain major clinical and engineering challenges. This talk presents a series of studies using patient-specific anatomical models and standardized virtual healthy-state phantom models representing pre-disease anatomy. Particle image velocimetry (PIV) experiments are combined with computational fluid dynamics (CFD) simulations to compare flow-field characteristics, wall shear stress distributions, and hemodynamic parameters in aneurysms with and without blebs under different flow conditions. The findings reveal an intrinsic association between bleb formation and localized low-wall-shear-stress regions and establish a discriminant-analysis framework based on hemodynamic indices, providing a new quantitative tool for clinical assessment of aneurysm rupture risk.

报告摘要二

Dual-plane stereoscopic particle image velocimetry (DP-s-PIV) can quantify time-resolved three-component velocity and vorticity vectors. This talk presents a 20 kHz dual-plane stereo-PIV test rig using two same-color laser sheets with a 100 ns delay, which separates the imaging processes of two camera pairs while keeping the resulting velocity error negligible. The short-delay method simplifies the experimental setup, especially for low-speed flows. To overcome the limited spatial resolvability of conventional cross-correlation evaluation, an optical-flow enhanced hybrid PIV scheme is extended to DP-s-PIV through 3D reconstruction and validated against the cross-correlation evaluation in DaVis 8.4. The method improves the spatial resolvability of the velocity field, provides clearer visualization of vortical structures, and enhances the precision of vorticity evaluation and vortex identification in a stratified swirling jet flow.

报告摘要三

X-ray angiography can visualize blood flow, but velocity assessment from two-dimensional projective images is affected by the “stacking effect” caused by projection through a three-dimensional volume. This study demonstrates the feasibility of assessing a 3D flow field with an optical flow method based on reconstructed 3D angiographic images. Blood flow with contrast-agent injection is first simulated in a patient-specific internal carotid artery model using an experimentally validated CFD model. Simulated multi-angle X-ray images are then generated according to the Beer-Lambert law and reconstructed by an algebraic reconstruction technique into a 72×72×60-voxel volume with a spatial resolution of 0.33 mm/voxel. The 3D optical flow method is applied to both the original and reconstructed images. The difference in estimated velocity magnitude is about 16%, while the relative averaged error against the CFD velocity distribution is 46%. Further improvement may be achieved with a trained machine-learning algorithm.

杨自丰教授简介

Prof. Zifeng Yang

Professor, Department of Mechanical and Materials Engineering, Wright State University
Director, Aerospace Systems Engineering Program · Director, Experimental Fluid Dynamics Laboratory

Prof. Zifeng Yang is a Professor in the Department of Mechanical and Materials Engineering at Wright State University. He serves as Director of the Aerospace Systems Engineering Program and Director of the Experimental Fluid Dynamics Laboratory.

He received his B.S. and M.S. degrees in Aerospace Engineering from Beijing University of Aeronautics and Astronautics in 2003 and 2006, respectively, and his Ph.D. in Aerospace Engineering from Iowa State University in 2009. He subsequently worked at Iowa State University as a lecturer and postdoctoral research associate before joining Wright State University in 2011. He was promoted to Associate Professor with tenure in 2017 and Professor in 2025.

His research interests and expertise include advanced flow diagnostic techniques; optical-flow velocimetry; particle image velocimetry (PIV) and stereoscopic PIV; blood-flow diagnostics and hemodynamics; wind energy and wind-turbine technology; film cooling and thermal management of gas turbine blades; micro air vehicles; and flow-structure interaction of built structures in strong winds.

Prof. Yang has led research supported by the National Institutes of Health SBIR Phase I and Phase II programs, Premier Health and the Boonshoft School of Medicine, the U.S. Air Force STTR program, and other sponsors. His honors include the Excellence in Professional Service Award, an AIAA outstanding service award, several best-presentation awards, and a first-place Art-in-Science Award. He has also served as a guest editor and held leadership roles in AIAA and the American Physical Society.