Research Of Aerodynamic And Acoustic Performance For A Marine Valve With Muffler

Steam turbine is widely used as efficient and dependable power resource in shipping industry.In order to regulate the speed,the parameters are changed by the lift of valve in marine turbine control system.With the increase of power,the dimension of control valve gets bigger.However,there is need on research of aerodynamic and regulation performance.In addition,the level of noise matters all lives of marine.The control valve has always been one of noise sources.Based on the demand on the power of marine,a new valve structure with muffler that could be installed was designed to improve adjusting regulation and the level of noise.In addition,an experiment was done to verify performance.The flow area was divided into a large numbers of areas due to penetrated holes in muffler.There were also two parts in pressure drop.So there was a big difference between new structure and conventional valve in adjusting regulation.The numbers and shape were certain in this paper.A porous model was put forward to simulate pressure loss in muffler as a simplified method.Then a model of control valve 3D flow filed was established to calculate flow filed by CFX,and thus such as flow parameters and pressure loss were acquired the inside fluids flow in different structures.It indicated that mass flow increased gently as the lift of valve.Regulation characteristic was based on the change of lift and area in muffler.The pressure ratio had a small influence on flow coefficient.Then characteristic of noise in the control valve were analyzed.The transient analysis of the valve flow field was made by large eddy simulation.In this way,parameters related to the time-varying characteristics were obtained.By LMS Virtual lab Acoustics,aerodynamic noise was calculated.The noise and balance of flow field were truly improved by new muffler.As the increase of circumferential holes,aerodynamic performance and noise level got better.A wind tunnel experiment on the aerodynamic performance and noise abatement of valve was tested.What is more,different mufflers were carried by contrast.Data we got in tests was filtered by using Bezier function.Different projects were compared in the form of flow coefficient graph.The relations showed pressure ratio,lift and the numbers of holes concerning the new structure.The numerical simulation result can predict experiment.In condition of equal mass flow and pressure ratio,muffler was a great way to reduce noise.The maximum decline could be about 7 dB.