February 29, 2024
Ehsan Izadpanah

Ehsan Izadpanah

Academic Rank: Associate professor
Address:
Degree: Ph.D in Mechanical Engineering
Phone: 09133570349
Faculty: Faculty of Engineering

Research

Title Numerical investigation on two-degree-of-freedom vortex-induced vibration of a circular cylinder in power-law fluids
Type Article
Keywords
Vortex-induced vibration Two-degree-of-freedom Circular cylinder Non-Newtonian fluid Power-law index Vortex shedding pattern
Journal JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
DOI https://doi.org/10.1016/j.jnnfm.2021.104535
Researchers Ali Ashouri (First researcher) , Ehsan Izadpanah (Second researcher) , Mohamad Hamed Hekmat (Third researcher) , Yasser Amini (Fourth researcher)

Abstract

In this paper, the two-degree-of-freedom (2DOF) vortex-induced vibration (VIV) of a circular cylinder in shear-thinning and shear-thickening non-Newtonian power-law fluids are numerically investigated. A virtual spring-damper-mass system is employed to predict the VIV of the cylinder. A comprehensive analysis is conducted to study the influence of dimensionless parameters, including reduced velocity () and power-law index () at a low Reynolds number () and low mass ratio () on the vortex shedding pattern, displacement frequencies, local apparent viscosity, friction coefficient, trajectories of the displacements, drag and lift coefficients, and the cylinder displacements. The results indicate that the apparent viscosity and the natural frequency of the system have a substantial effect on the characteristics of the VIV of the cylinder. By changing the values of the reduced velocity, various vortex shedding patterns such as 2S, 2P, S + P, and complex modes are observed for the non- Newtonian fluids, and several motion trajectories other than the typical figure “8″ are analyzed. By increasing the power-law index, the range of the lock-in region and the corresponding reduced velocity of the maximum transverse vibration amplitude change.