Zhan Hanxin

AWARDEE OF MATHEMATICS PRIZE

ZHANG HANXIN

Abstract

Zhang Hanxin,professor of the China Aerodynamics Research and Development Center.He was born in January,1936 in Pei County,Jiangsu Province.He Graduated from department of Hydraulics engineering,Tsinghua University in 1958,and obtained degree from graduate school of Chinese Academy of Sciences in 1963.He was elected as a member of Chinese Academy of Sciences in 1991.His achievements and contributions in fluid mechanics mainly cover the following fields:
1.3D separated flows
Established mathematical conditions for 3D steady flow to separate and demonstrated that a separation line is running together of limiting streamlines and itself is also a limiting streamline,but the convergent asymptote of limiting streamlines does not certainly represent separation.Revealed the topological structure of alternative arrangement of saddles and nodes on the separation line.Found three kinds of initial states which can transform into each other and two kinds of initial states for open separated flows.Proposed a separation criterion for 2D unsteady flow.
2.CFD
Based on the physical analysis and the principle of entropy increase,he has established NND difference scheme for solving Euler and NS equations,which is no free parameter,containing no oscillation and dissipative.
3.Applications in Aerospace Sciences
His contributions in this area lie on that he has theoretically solved a number of challenging coupled problems in aerodynamic force,heat transfer,ablation,erosion and is responsible for developing corresponding software packages.
4.Topology of vortex motions and cross flows
Theoretically described the cross flow topology of vortex motions and the initial state of vortex breakdown,pointing out the essential distinctions between vortices with subsonic and supersonic axial velocity.Revealed topological structure of cross flow of separated flows.Elucidated evolution of leeward flow of a slender body and demonstrates that as the angle of attack increases,the transition of near wake flow from periodic to chaotic state is not only through quasiperiodic route,but also through period doubling subharmonic bifurcation.
He received two second class Awards of National Prize of Progress in Science and Technology and a second class Award of Nature Sciences,besides five first class Awards of Ministry Grade Prize of Progress in Science and Technology from the State Commission of Science,Technology and Industry for National Defense.