TY - GEN

T1 - Computational study of heat and fluid flow around a rotary oscillating cylinder at a high Re number

AU - Hadžiabdić, M.

AU - Palkin, E.

AU - Mullyadzhanov, R.

AU - Hanjalić, K.

N1 - Funding Information: This work is funded by the Russian Science Foundation grant No. 14-19-01685. The computational resources are provided by Novosibirsk State University Computing Centre (Novosibirsk), Siberian Supercomputer Centre SB RAS (Novosibirsk) and Joint Supercomputer Centre RAS (Moscow). Publisher Copyright: © 2018 Begell House, Inc.

PY - 2018

Y1 - 2018

N2 - The paper deals with flow over a rotationally oscillating cylinder at a subcritical Reynolds number (Re = 1.4×105) that is an order of magnitude higher than previously reported in the literature. The focus is on the control of drag force and heat transfer. Five forcing frequencies f = fe/f0= 1, 2.5, 3, 4, 5 and three forcing amplitudes Ω=ΩeD/2U∞ = 1, 2, 3 are considered, where f0 is the natural vortex-shedding frequency, U∞ the free-stream velocity and D the cylinder diameter. We employed 3D URANS based on a second-moment closure, which was earlier verified by LES and experiments on flows over a stagnant, as well as two cases of rotary oscillating cylinders at the same Re number. The dramatic drag reduction occurs at frequencies equal and larger than f = 2.5, while no reduction appears for the cylinder that oscillates with the natural frequency. The drag reduction is the result of a modified vortex shedding topology and related pressure field characterized by shrinking of the low pressure region behind the cylinder, all imposed by the rotary oscillation. The heat transfer from a cylinder wall is enhanced by the rotary oscillation resulting in the local Nusselt number which distribution along the cylinder wall strongly depends on the forcing amplitude and frequency.

AB - The paper deals with flow over a rotationally oscillating cylinder at a subcritical Reynolds number (Re = 1.4×105) that is an order of magnitude higher than previously reported in the literature. The focus is on the control of drag force and heat transfer. Five forcing frequencies f = fe/f0= 1, 2.5, 3, 4, 5 and three forcing amplitudes Ω=ΩeD/2U∞ = 1, 2, 3 are considered, where f0 is the natural vortex-shedding frequency, U∞ the free-stream velocity and D the cylinder diameter. We employed 3D URANS based on a second-moment closure, which was earlier verified by LES and experiments on flows over a stagnant, as well as two cases of rotary oscillating cylinders at the same Re number. The dramatic drag reduction occurs at frequencies equal and larger than f = 2.5, while no reduction appears for the cylinder that oscillates with the natural frequency. The drag reduction is the result of a modified vortex shedding topology and related pressure field characterized by shrinking of the low pressure region behind the cylinder, all imposed by the rotary oscillation. The heat transfer from a cylinder wall is enhanced by the rotary oscillation resulting in the local Nusselt number which distribution along the cylinder wall strongly depends on the forcing amplitude and frequency.

UR - http://www.scopus.com/inward/record.url?scp=85137458311&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/aebe7b92-5f3f-3301-9035-76b65b0f762d/

U2 - 10.1615/THMT-18.340

DO - 10.1615/THMT-18.340

M3 - Conference contribution

AN - SCOPUS:85137458311

SN - 9781567004687

T3 - Proceedings of the International Symposium on Turbulence, Heat and Mass Transfer

SP - 359

EP - 370

BT - THMT 2018 - Proceedings of the 9th International Symposium on Turbulence Heat and Mass Transfer

PB - Begell House Inc.

T2 - 9th International Symposium on Turbulence Heat and Mass Transfer, THMT 2018

Y2 - 10 July 2018 through 13 July 2018

ER -