Study on wind pressure characteristics on quasi-oval shaped iced conductor at critical Reynolds numbers regime

By employing the rigid model wind pressure test,the wind loads distribution on quasi-oval shape iced conductor is obtained at different Reynolds numbers,and the effects of Reynolds number on wind loads as well as galloping stability in the direction transverse to the mean wind direction are analyzed by comparing the mean wind loads,fluctuating wind loads and wind force spectra.When the Reynolds number reaches the critical range,compared to the situa-tion at sub-critical range,the mean drag coefficients decrease,and mean lift coefficients occur at the symmetric case and severely vary with the wind direction;wind pressure coefficients are sen-sitive to the wind directions.Vortices shedding,which is supposed to be regular at sub-critical range,is irregular at critical range;the correlation of wind pressure around the cross section is weakened,and predominate frequency disappears.The steep slope of the lift coefficient versus angle of attack corresponding to Reynolds number at critical range makes the galloping in the di-rection transverse to the mean wind direction easy to happen.