GAS-LIQUID TWO-PHASE CROSS-FLOW INDUCED VIBRATION OF STAGGERED TUBE ARRAYS DUE TO VORTEX SHEDDING

摘要

The vortex shedding from three row circular cylinders with the same diameter in staggered arrangement is experimentally investigated. The test tubes are made of acrylic grass cylinders whose diameter is 30mm. The gas-liquid two-phase gap Reynolds number ranges from 2.0 X 10~4 to 6.0 X 10~4, and the range of void fraction is from 0 to 0.3. Research results show that periodical vortex shedding happens when void fraction is less than 0.14; As the transverse spacing ratio is less than 2.0,gap-flow is bi-stable deflective flow; Strouhal number in two-phase flow reduces with the increase of void friction; Weaver curve of Strouhal number could be used approximately as the transition curve from vortex shedding to non-vortex shedding under two-phase flow.