Experimental study on aerodynamic characteristics of a large-diameter ice-accreted cylinder without icicles

Abstract

The aerodynamic characteristics of a circular cylinder (diameter ​= ​600 ​mm) with and without ice accretion (without icicles) were studied via wind tunnel tests (including simultaneous multi-pressure and force measurements) for Reynolds numbers (Re) of 1.29 ​× ​105–1.27 ​× ​106. The influences of wind angle of attack α, turbulence intensity Iu, relative surface roughness k, and accreted ice shape on the mean aerodynamic force coefficients (MAFCs), mean pressure coefficients, and pressure correlation coefficients were comprehensively investigated. Experimental results showed that the MAFCs of the ice-accreted cylinders exhibited significant Reynolds number effects, and the effects were closely related to the ice shape. The effects of Iu and k on the drag force of the ice-accreted and ice-free cylinders were similar. The remarkable lift force due to the asymmetric ice accretion could be reduced by increasing k and Iu. The effect of α on the MAFCs was related to the ice shapes and Re. The flow reattachments in the critical and supercritical regimes were examined to reveal the flow states around the finite ice-free and ice-accreted cylinders. The flow-fields around the finite ice-free and ice-accreted cylinders had significant three-dimensional effects, which could be weakened by introducing the Iu and k. The findings of this study could provide further understanding of the effect of ice accretion on the aerodynamic characteristics of circular cylinders. The results could be used as beneficial references in the wind-resistance design of ice-accreted circular cylinders.