讲座时间：2024年1月2日 10:30-12:10
讲座地点：雁栖湖校区 教1-214
讲座题目：Phenomena in shear electrically conducting flows under influence of a magnetic field
讲座嘉宾：
Jurijs Kolesnikovs，Graduated from Aviation University, Kazan, Russia in 1967. Working at the Institute of Physics of the Academy of Sciences of Latvia, Riga in the field of magnetohydrodynamics, he defended in 1973 his PhD thesis specialty of mechanics of liquid, gas and plasma. In 1986 he defended his thesis for the degree of Doctor of Science in the field of MHD instability and turbulence in liquid metal flows at the Polytechnic University, St. Petersburg, Russia. In 1987, he was awarded the title of Professor of Physics by the Ministry of Higher and Special Education of Russia. In 1993 he defended his dissertation for the degree of Doctor Habilitation in Physics at the Academy of Sciences of Latvia, Riga. Since 1998 till now he is an Invited- and Guest-Professor at the Ilmenau University of Technology, Germany.
Area of scientific working: Study of instability, turbulence in liquid metal flows in the presence of magnetic field and creation of anisotropic vortical turbulent structures in MHD flows to suppress or directed enhance of heat and mass transfer processes.
讲座内容：
A liquid metal flows in the form of round and plane jets entering a duct in the presence of a magnetic field of different orientation are analyzed. The flow structure and fluctuation properties are largely determined by the value of the Stuart number N proportional to the ratio of electromagnetic Lorentz forces to inertia forces. We consider phenomena: i) the devolution of a round jet into a flat one in a transverse magnetic field with emergence of highly intensive two-dimensional Kelvin-Helmholtz instability; ii) an increase in the range of a round jet along an axial magnetic field and the appearance of a pinch effect characteristic to a plasma jet; iii) decay of a flat jet in a strong transverse field into three jets - a central and two near-walls, protruded along the field, generating 2D perturbations of high-intensity; iv) appearance of “negative” turbulent viscosity in a flat jet with two-dimensional structure of turbulence defining opposite the transfer of turbulent energy into the jet flow.
