Study On Vibration Characteristics Of Fluid-Structure Coupling Indoor Water Supply Pipeline Based On ANSYS Workbench

Indoor water supply pipe is an indispensable fluid transport element in daily life.In the process of water use,pipe vibration is a common phenomenon,but severe vibration will generate large noise,loosen the pipe fixing pieces,and even cause fatigue damage.Leakage damage seriously affects the normal life of the residents.If blindly reforming the indoor pipeline,it will not only waste time and resources,but also bring about less satisfactory results.At present,there are few studies on the vibration characteristics of indoor water supply pipelines.Vibration calculations have not been considered in actual projects.The existing vibration analysis also only performs one-way fluid-structure coupling analysis for typical pipe sections.Therefore,in order to reduce the vibration displacement of the pipeline and improve the durability of the pipe,it is necessary to use bi-directional fluid-structure coupling to study the vibration characteristics of the indoor water supply pipeline.It is expected that the design and construction of the water supply pipeline can be guided to ensure low noise,stable and safe operation of the pipeline.In this paper,the water supply pipeline vibration was initially tested according to the experiment,and then the finite element model of the indoor water supply pipeline was established based on ANSYS Workbench.A two-way fluid-structure coupling analysis was performed on the pipeline,and a vibration reduction retrofit scheme was proposed based on the results of the finite element analysis.The experimental verification of the effect of vibration reduction was carried out.The specific research contents are as follows.1.Taking the indoor water supply pipe of a household as an example,a full-scale pipe model was produced in the laboratory.14 kinds of combination conditions were set according to the conditions of use(Water valve A opening is 0°,90°,water valve B opening is 0°,15°,30°,45°,60°,75° and 90°).Vibration displacement tests were performed for each condition.It was found that when valve A is closed and the opening of valve B exceeds 50%,the pipe vibration is large.In working condition 6(water valve A opening is 0°,water valve B opening is 75°),the vibration displacement of the water supply pipe reaches a maximum.Through the monitoring of the flow velocity,it was found that the vibration displacement was significantly increased when the flow velocity in the tube was greater than 1.0 m/s.It was concluded that reducing the flow velocity was an effective method for controlling the vibration of the pipeline.2.According to the laboratory physical model,using the ANSYS Workbench software to establish a finite element model.The modal analysis was first performed to obtain the natural frequencies and corresponding mode shapes of the pipeline.Through the analysis,it is found that the more pipeline water filling,the more the natural frequency of the pipeline is decreasing,and the vibration mode of the pipeline remains basically unchanged.According to the low-order frequency,the fluid-structure coupling time step was estimated.Using the bidirectional coupling module to establish the finite element model for the maximum displacement conditions obtained by the test,it was found that the simulation results were basically consistent with the experimental results and the rationality of the model was verified.Using this model,a two-way fluid-structure coupled simulation study was conducted on water supply pipelines under different conditions of inlet pressure,support,and wall thickness,and the following conclusions were reached.First,the smaller the pipeline inlet pressure is,the smaller the vibration displacement of the pipeline is,and as the inlet pressure decreases,the trend of the displacement decreases tends to be gentle.Second,the fixed constraint is better than the simple support constraint in controlling the vibration displacement of the water supply pipeline.Third,the use of thicker pipes can effectively reduce the vibration displacement of the pipe.3.According to the results of the finite element analysis,the following four vibration reduction renovation programs are proposed.The first option is to increase the fixed constraints.The second option is to reduce the water pressure in the pipeline.The third option is to change simple support constraints to fixed constraints.The fourth option is the synthesis of appeal measures.Through experiments,it has been found that increasing the damping effect of pipeline constraints is obvious,reducing the water pressure has a certain damping effect but not obvious.The fixed constraint can restrain the vibration of the pipeline more than the simple support constraint.The fixed constraint can limit the vibration of the pipeline more than the simple support constraint,and scheme 4 has the best effect of reducing the pipeline vibration.