Experimental Study On Rigid Cylindrical Flow And Vortex-induced Vibration

The rigid cylinder existed in hydrolic projects,including high-piled wharfs,sea-crossing bridges,offshore platform risers,harbor breakwater,and pier pile foundations;On the other hand,the trunk-like structure of arbors and other tree-like vegetation on riverbanks will also have an impact on flooding during river flooding.Therefore,it is very necessary to carry out experimental research on the flood safety and the rigid cylindrical structure overcurrent situation.this article study the river flow resistance characteristics with different column arrangements,arrangement density,and water flow;In addition,we also conducted the distribution of velocity and vorticity fields.To provide reference for related projects and research,the specific research content is as follows.Aiming at the change of the flow-resisting characteristics of river channels caused by the rigid cylinder structure in the open channels,a rigid cylindrical experimental system was built,the measurement and analysis of the drag coefficient and roughness coefficient of the tank were carried out.The experimental results show that the roughness coefficient of the channel with a rigid cylinder grows significantly;Sensitivity analysis results show that the sensitivity of the above factors to river flow choke characteristics is as follows:flow rate,arrangement type,arrangement density.For the distribution of the velocity field during the over-flow of rigid cylinder structure,the piv system was used to measure the flow of water through different parts of the column.The velocity of the surface layer increases significantly with the internal flow velocity constantly adjusted,the flow velocity decreases near the bottom of the tank which show that the existence of a rigid cylinder structure can effectively reduce the flow velocity in the downstream area of the column.For the adjustment of vorticity field caused by the existence of a rigid cylinder structure in of the flow velocity distribution.The results show that the turbulence intensity of the internal flow of the rigid cylinder structure is significantly enhanced,and the maximum turbulence intensity in the downstream of the column appears in the central region of the water body.In this article,the flow resistance,flow field and vorticity field distribution of a rigid cylindrical in the open channel were studied,to Provide theoretical support for ecological river construction and port engineering protection.