切角凹槽矩形截面桥塔的气动特性试验研究

Experimental Study on the Aerodynamic Characteristics of a Rectangular-section Bridge Pylon with Corner Cuts and Slots

基于刚性模型测压风洞试验方法,研究了不同切角率和凹槽率的矩形截面桥塔气动特性随风向角的变化规律.结果表明,切角凹槽矩形截面桥塔气动特性随风向角的变化会出现2个临界风向角αcr1和α_(cr2),临界风向角附近气动特性出现突变.当0°≤α<α_(cr1)和α_(cr2)<α≤90°时,随风向角增大,平均阻力系数和脉动升力系数先减小后增大,斯托罗哈数先增大后减小;当αcr1<α<α_(cr2)时,平均阻力系数和脉动升力系数变化不大,斯托罗哈数消失.2个临界风向角间的范围随切角率的增大而减小,随凹槽率的增大而增大.同一风向角下,气动特性受凹槽率影响较小;随切角率的增大,平均阻力系数减小,斯托罗哈数增大,脉动升力系数变化较小.

Based on the wind tunnel test method using a rigid model for measuring pressure,the change rule of aerodynamic characteristics of a rectangular cross-section bridge pylon with different corner cutting and slot-ting rates with the wind angle was investigated.The findings indicate that a rectangular cross-section bridge py-lon with cut corners and slots displays varying aerodynamic characteristics depending on the wind angle,exhibiting two critical wind angles,namelyαcr1 andα_(cr2).Additionally,it was observed that the aerody-namic characteristics experience sudden changes when the wind angle approaches the critical values.When the wind angle increases within the range of 0°toαcr1 andα_(cr2)to 90°,there is a decrease followed by an increase in both the mean drag coefficient and the fluctuating lift coefficient,while the Strouhal number shows an increase followed by a decrease.When the wind angle is betweenαcr1 andα_(cr2),there is little variation in the mean drag coefficient and fluctuating lift coefficient,and the Strouhal number dis-appears.The range between the two critical wind angles diminishes with rising corner-cutting rates,while it ascends with growing slotting rates.At the same wind angle,there is minimal influence on aer-odynamic characteristics based on the slotting rate.As the corner-cutting rate increases,the mean drag coefficient decreases,the Strouhal number increases,and the fluctuating lift coefficient varies less.