TY - JOUR

T1 - Heat transfer and flow around cylinder

T2 - Effect of corner radius and Reynolds number

AU - Abdelhamid, Talaat

AU - Alam, Md Mahbub

AU - Islam, Md

N1 - Funding Information:
The authors wish to acknowledge the support given by the National Natural Science Foundation of China through Grants 11672096 and 91752112, by Research Grant Council of Shenzhen Government through grant JCYJ20180306171921088, and by Khalifa University of Science and Technology, UAE, through Research Grant CIRA-2020-057.
Publisher Copyright:
© 2021

PY - 2021/6

Y1 - 2021/6

N2 - This numerical study aims to investigate the flow around, heat transfer from, and aerodynamic forces on a square cylinder with the corner radius ratio r/R = 0.0 – 1.0 and Reynolds number Re = 40 180, where r is the cylinder corner radius and R is the half side width of the cylinder. The critical Reynolds number (Recr) for the onset of vortex shedding is found to vary from 49.5 to 46.75 when r/R is increased from 0.0 to 1.0. The dependence of the flow topology on the Re – r/R domain leads to four major flow patterns: steady trailing-edge separated flow, unsteady trailing-edge separated flow, unsteady separation-bubble flow, and unsteady leading-edge separated flow which are distinguished by flow separation, reattachment, boundary layer, and separation bubble. Accordingly, forces, Strouhal number, Nusselt number, and wake structure parameters all are dependent on r/R and Re. The dependence of each parameter is presented in the r/R – Re domain. The Strouhal number and Nusselt number are equally sensitive to both r/R and Re, increasing with increasing r/R and Re. Forces, on the other hand, are more sensitive to Re than r/R. The maximum velocity in the shear layer increases with r/R and Re while the boundary-layer displacement thickness behaves oppositely, shrinking with increasing r/R and Re.

AB - This numerical study aims to investigate the flow around, heat transfer from, and aerodynamic forces on a square cylinder with the corner radius ratio r/R = 0.0 – 1.0 and Reynolds number Re = 40 180, where r is the cylinder corner radius and R is the half side width of the cylinder. The critical Reynolds number (Recr) for the onset of vortex shedding is found to vary from 49.5 to 46.75 when r/R is increased from 0.0 to 1.0. The dependence of the flow topology on the Re – r/R domain leads to four major flow patterns: steady trailing-edge separated flow, unsteady trailing-edge separated flow, unsteady separation-bubble flow, and unsteady leading-edge separated flow which are distinguished by flow separation, reattachment, boundary layer, and separation bubble. Accordingly, forces, Strouhal number, Nusselt number, and wake structure parameters all are dependent on r/R and Re. The dependence of each parameter is presented in the r/R – Re domain. The Strouhal number and Nusselt number are equally sensitive to both r/R and Re, increasing with increasing r/R and Re. Forces, on the other hand, are more sensitive to Re than r/R. The maximum velocity in the shear layer increases with r/R and Re while the boundary-layer displacement thickness behaves oppositely, shrinking with increasing r/R and Re.

KW - Corner radius ratio

KW - Drag reduction

KW - Flow structure

KW - Heat transfer

KW - Steady flow

KW - Unsteady flow

KW - Vortex shedding

UR - http://www.scopus.com/inward/record.url?scp=85101418349&partnerID=8YFLogxK

U2 - 10.1016/j.ijheatmasstransfer.2021.121105

DO - 10.1016/j.ijheatmasstransfer.2021.121105

M3 - Article

AN - SCOPUS:85101418349

SN - 0017-9310

VL - 171

JO - International Journal of Heat and Mass Transfer

JF - International Journal of Heat and Mass Transfer

M1 - 121105

ER -