Hydraulic Experiment And Numerical Simulation Research Of Building Drainage System

Building drainage system is an essential part of the building.Now we have less related research of scientific experiment and the test standard is not enough.Test results from abroad are not applicable to us.So it is important to do the basis research of the building drainage system.The pressure fluctuations of internal drainage system have important impact on the normal operation of the whole system and the flow pattern of internal system is related to pressure fluctuations.This article mainly study about hydraulic experiments and numerical simulation research around the flow pattern of internal building drainage system:(1)Numerical simulation of the flow state affected by inflow angle in the tee coupling tube was carried out by the Fluent software.The simulation results showed that it would be a chaotic flow area when the branch pipe flow and stand pipe flow converged in the tee.The area affected the flow of water.The scope of the area is decrease as the inflow angle of branch pipe increased in the case of other factors remained the same.This showed that the flow state in the tee coupling tube can be improved and drainage is smoother as the inflow angle increases.(2)A combination of hydraulic experiment and numerical simulation was used to do some research about setting a sheeting behind the branch of the tee by using.The results showed that the sheeting have a good effect of stablishing pressure fluctuations in the drainage system when the stand pipe flow is small and there is no significant effect as the stand flow increases to a certain level.This showed that the improvement is mainly affected by the stand pipe flow as the sheeting reduced the open area of stand pipe and caused trouble for the stand flow.(3)The factors,such as flux,drainage height,pipe diameter of horizontal branch and gradient,have an impact on the flow pattern of internal horizontal main pipe,especially flux.Numerical simulation of the flow state affected by curvature of drainage elbow was carried out by the Fluent.The simulation results showed that the flow state in the drainage elbow could be improved and the drainage ability was advanced as the radius of curvature increases.(4)Looking for critical value of bend curvature when hydraulic jump occurs with the method of theoretical calculation by analysing the relationship between the flow and the elbow bend radius when horizontal main stream is in the critical flow.But calculated results with terminal velocity theory were not consistent with the actual observation.The reason might be that the terminal velocity theory was not suitable for the theoretical calculation about the elbow bend radius.So it is an important problem to find a suitable calculation theory about bend curvature and then the study about critical value of elbow bend radius will be continued.