两相流作用下旋转三角形排列管束流弹失稳振动特性实验研究

Experimental study on fluidelastic instability of rotated triangular tube bundles subjected to two-phase cross flow-critical velocity

在空气-水两相流实验装置上对节径比为1.48的旋转三角形排列的传热管束进行了两相流作用下的流弹失稳振动特性实验,分别对传热管的升力方向和阻力方向进行测量,研究了传热管束在空泡份额为0,20%,40%,60%,80%和90%下漩涡脱落情况以及发生流弹失稳的临界流速。结果表明:阻力方向没有发生失稳现象;对于同种频率的传热管束,临界流速随着空泡份额的增加而增大;在同一空泡份额下,临界流速与传热管频率成正比;空泡份额低于20%时,传热管束会出现漩涡脱落。

Vibration characteristic experiments of fluidelastic instability on the air-water two-phase test device are conducted about rotated triangular tube array with the pitch-to-diameter ratio of 1.48 subjected to air-water cross-flow.Both of lift direction and draft direction of tube bundles are tested.Critical velocities of two different frequency tube bundles for fluidelastic instability are measured in different void fractions of 0,20%,40%,60%,80%and 90%.The results show that,fluidelastic instability does not occur in draft direction.The critical velocity increases with the increase of void fraction for tube bundle with the same frequency,and is proportional to tube frequency for the same void fraction.When void fraction is less than 20%,vortex shedding occurs in the heat transfer tube bundle.