Prediction And Control Research On The None-steady Flow-induced Noise In High Speed Impeller Fuel Pump System

Accompany with design for lower noise emission at the very beginning of the regenerative fuel pump design stages,comprehensively carrying out fuel pump and tank system’s vibro-acoustic optimization,is the only way to the vibro-acoustic performance improvement and the shorten of product R&D cycle time.This article was carried out,under these circumstances,to encompass the general methods and concrete optimization design research of the noise radiation modeling of regenerative fuel pump tank system.The main contents of this article are:This article researched the modeling method of fluid induced noise of fuel tank-pump system.Taking a certain type of regenerative vehicle fuel pump-tank system as an example,vibration and noise radiation test was carried out to analyse the noise source,based on the computational fluid dynamics and acoustic theory,the finite element method was applied to estimate and calculate the fuel pump system sound pressure level and sound power level.For the simulation of fluid charateristics in the fuel pump,the model was validated by the test data,and then the fluid pressure fluctuation distribution was discussed in the time and frequency domains.The simulation was carried out under different working conditions,then the head of delivery and efficiency were obtained under different flow rate conditions.The wall pressure fluctuations inside the pump,obtained from the CFD simulation results,were prepared as excitation source for fluid noise analysis in the next step.Based on the above work,the article established acoustic FEM model with vibro-acoustic coupling technique to predict the sound pressure level at the monitor point,which agreed well with the sound radiation test data.Finally,a general process and method for simulating the fuel pump fluid induced noise was built,which was suitable to estimate the vibro-acoustic characteristics of the fuel pump system during the R&D stage and product stages.The fluid induced noise optimization method was studied,the influence of geometric parameters of fuel pump on the sound radiation was discussed,such as rotating speed,blade number,blade thickness and so on.The results of different schemes showed that,the blade number influenced the noise level most significantly,we can increase or decrease the blade number to control the noise level,only if the efficiency decrease little.Mechanism of how the impeller with unequal blade angles influence radiated noise level was theoretically derived,and a certain impeller was designed,which could improve the noise level at high frequency domain.Considering the influence on the 47 harmonic noise of different schemes,and the complexity of different schemes,the modification of the inlet port geometry,which greatly reduce the sound pressure level at high frequencies,was adopted by the company,and the samples were produced and tested,the results showed that the high frequency noise level especially the 47 harmonic noise level was significantly reduced.The theoretical analysis of noise source identification derived the equations for solving parameters identification,which was proved to be valid by numerical simulation.Then the model obtained the noise source parameters based on fuel pump sound radiation test,and the noise source model was loaded in the acoustic FEM model of fuel pump module to simulate the sound power level,which was validated by experimental results.Based on the above source model,acoustic FEM model of the fuel pump-tank system was achieved using AML and vibro-acoustic coupling technique,of which the simulational sound pressure results agreed well with test data,especially at certain order frequencies.Systematic and comprehensive benchmarking data accumulation of the fuel pump system noise characteristics was built to support the design and optimization during design and product stages.The computational and experimental methods were used to collect the data of characteristics indexs,and the estimated criteria of the fuel tank-pump system vibro-acoustic properties was discussed.A general process of benchmarking for evaluating the fuel pump system vibro-acoustic properties was established,which was suitable to benchmarking the target products during the design stage.