Vibration And Noise Reduction Research Of Fluid Pippline System

Nowadays, Noise pollution is listed as one of the major three problems of the worldpollution. Noise is everywhere in all human activities. People focus on noise pollutionis no less than that on other environmental problems such as water pollution and airpollution. In high-grade areas such as military project, medical treatment, andscientific research, noise pollution has become an obstacle hinders the develop ofmankind. So noise pollution has become the key and difficult problems badly neededto be solved in the industry at home and abroad. With the improvement of humanliving standards, the requirements to our environment has become much higher. Sowith the bad influence to human’s health noise pollution has become the majorenvironment problem. Fluid pipe noise problem, whose source is pumping station,seriously influences the live and work safety in daily life. Through theoretical andexperimental researches, this paper is of important theoretical and practicalapplication significance in reducing the vibration noise of liquid-filled pipe system byinstalling water pipe muffler to the exit of high-level water pumping station.In this paper, a new kind of underwater sound-absorbing composites named naturallatex-based diatomite is chosen as the research subject, and this material is applied inthe high-level water piping system by being made into water pipe muffler. Thevibration attenuation and noise reduction problems are also researched in the paper.The mechanical properties and microstructure characterization of the new underwatersound-absorbing composite material are tested, the noise generating mechanism ofpiping vibration is analyzed and a mathematical model of the elbow is established.The data suggest that the noise is mainly caused by the flow pressure pulsation andcavitation white noise. The absorption effect of water pipe muffler to the fluidpressure pulsation is analyzed by discretizing the new composite material andestablishing multi-DOF motion equations combined with mathematical model of fluiddomain. The relationship between the pore size structure and energy absorptioncoefficient is analyzed by establishing the aerodynamic mathematical model of diatomite. The three-dimensional model of water pipe muffler is established,simulation of water pipe muffler for two-way fluid-structure interaction is done byAnsys, and the result is analyzed comparing with the simulation result themathematical model of multi-DOF established by Simulink software. The entitativewater pipe muffler model is made and then is used in simulation experiment to reducethe noise produced by automobile exhaust, and1/3octave spectrum analysis is madeusing Matlab.Through the experimental and theoretical analysis, such conclusions are got: theoptimal diatomite content is30%; the result of the comparison of Ansys simulationand Simulink simulation shows that the absorption of the water pipe muffler to waterpressure pulsation amplitude is obvious, natural latex is acoustic inert material and itsdamping performance is excellent to bate the energy of noise propagation to a largeextent, the absorption effect of diatomite on the high-frequency noise is remarkableaccording to the spectrum analysis and acoustic experiment.