Seminar "Numerical simulation of high-Wi viscoelastic drag-reducing turbulence" by Prof. Hongna Zhang

Speaker

Prof. Hongna Zhang 
Tianjin University, School of Mechanical Engineering, Associate Professor of Yingcai Program

Title 

Numerical simulation of high-Wi viscoelastic drag-reducing turbulence

Abstract

Viscoelastic fluid widely exists in nature and engineering field. The unique rheological properties make viscoelastic fluids show different flow patterns from Newtonian fluids, such as turbulence drag reduction effect at high Re number, elastic turbulence at very low Re number and elastoinertial turbulence phenomenon recently discovered. These unique flow patterns provide potential thermal flow control ideas for different engineering fields. For a long time, numerical simulation of viscoelastic fluid flow faces the challenge of the well-known high Wi numerical problem, which significantly limits our understanding on viscoelastic turbulence especially under strong elasticity. Moreover, the viscoelastic drag-reducing turbulence has been investigated for several decades. The recent introduction and discovery of elastoinertial turbulence has overturned the long-term understanding of drag-reducing turbulence, and it is urgent to further explore the essence and mechanism of drag-reducing turbulence on this basis, and construct the correlation between turbulent flow states of viscoelastic fluids. In this talk, I will talk about our recent progress on the development of the numerical methods for high-Wi viscoelastic turbulence, the new understanding of elasto-inertial turbulence as well as the drag-reducing turbulence based on our numerical methods.