Measurement And Analysis Of Side-by-side Circular Cylinders With Gas-sloid Synchronization Signals

Side-by-side circular cylinders is a kind of velocity field that can produces autoexcitation and exists bi-stable phenomenon in certain range.Based on former researches and to the characteristic of the velocity field,this paper designs the experiment formula that can suitablely mesure the signal.Also it makes some improvements to the instruments.After the simultaneous signals are collected,it does some time-frequency analyze.The following works are done:1.Slotted the top and both sides of the wind tunnel,make closures to ensure the air tightness;2.Design the cylinders,do the researches on pasting the strain gauge and debugging the instruments;3.Design the bearing and the slot,multi-probes moving stent;4.Simultaneously collect the gas-sloid synchronization signals;5.Make EMD to the full circle signals,give out time-frequency maps of the correspoding points;6.Collect the fluctuating signals along the velocity field,do WVD analyze of the kinetic behavior;7.Make CFD simulation to some conditions preliminarily.The results prove that different kinds of flow patterns will present by different ranges.In the near range situation,it can be seen an a single cylinder.And we also find that in the bi-stable situation range,at the speed of 2mps,the flow field stays critical bi-stable state.When at the speed of 5mps,the flow field contains two kind of frequency:the swing frequency of the wake and the off frequency of the vortex,and the former is higher than the latter,even submerged it.So attention this on engineering.