错列双管涡激振动风洞实验研究

Wind Tunnel Experiment on Vortex-induced Vibration of Staggered Double Circular Tube

针对横向流作用下换热器管束的涡激振动问题,采用低速回流式风洞对错列双管结构的涡激振动特性进行了实验研究,测量并分析了横向流作用下雷诺数和节径比对双圆管结构涡激振动特性的影响。实验中错列双管结构的水平距L/D范围为1. 5～3. 0,错位距H/D范围为0. 00～0. 75,风速U范围为0～18m/s。实验结果表明:在实验流速范围内,结构振幅先随流速的增加缓慢变化,流速达到临界值时振幅会突变增大,进入锁频区域,出现涡激共振现象。错列双管结构随水平距的增加,上游管尾流干扰对下游管柱的影响减弱。错位距较小时,下游管临界流速更小,锁频区间更宽。

Considering the vortex-induced vibration of heat exchanger’s tube bundle under cross-flow action,adopting a low-speed wind tunnel to investigate vortex-induced vibration characteristics of staggered double-tube structure experimentally and the effect of both Reynolds number and distance on it was analyzed under cross-flow action.The horizontal distance( L/D ) range of the double-tube structure in the experiment was L/D= 1.5~3.0,H/D =0.00~0.75,and flow velocity U =0~18m/s.The results show that,within experimental flow velocity range,the structure amplitude slowly changes with the increase of the flow velocity;and when the flow velocity reaches a critical value,the amplitude would sharply increase and the vortex-induced resonance phenomenon would occur in the lock-in region;when the horizontal distance ( L/D )of the structure increases,the influence of the upstream tube’s wake flow disturbance on the downstream tube column decreases;when the horizontal distance H/D is small,the critical flow rate of the downstream pipe is smaller and the frequency locking range is wider.