Study On Oil Sloshing Characteristics And Wave Suppression Design In Fuel Tank Of Vehicles

Fuel tank is an important part of vehicle.The safety of the vehicle is closely related to the fluid sloshing in the fuel tank.The violent shaking of the oil will damage the structure of the fuel tank and negatively affect the quality of the oil.How to suppress oil sloshing and enhance vehicle safety is an urgent problem for many enterprises.This paper takes the oil sloshing in the fuel tank of a vehicle as the research object,and carries out the research on the characteristics of the oil sloshing in the fuel tank of the vehicle and the wave suppression design.It is of great significance and provides a reference for the structural optimization design of the fuel tank.The main contents and conclusions are as follows:（1）Study on sloshing experiment and numerical method in fuel tank.The equivalent tank model is established.The experiment and numerical simulation of the liquid sloshing process are carried out through the horizontal excitation experiment platform and the dynamic grid coupled VOF method.The numerical results are compared with the experimental results to verify the feasibility of the numerical model and calculation method in studying the dynamics of liquid sloshing in the fuel tank.（2）The influence of the baffle in the fuel tank on the sloshing characteristics of the liquid.The response law of impact pressure to excitation frequency is explored,the characteristics of impact pressure under baffle with different solidity ratio are analyzed,and the evolution mechanism of vortex flow structure near baffle is explored based on vortex dynamics.The results show that the shock pulse pressure and non shock ordinary hydrodynamic pressure lead to the double peak phenomenon of the pressure curve in the shaking process.The solidity ratio of the baffle increases,the weaker the liquid sloshing amplitude,the lower the pressure peak width gap in the steady state,and the smaller the peak gap between the transient state and the steady state.The greater the excitation amplitude,the greater the range and strength of the vortex structure and the distance between the vortex core and the baffle,and the more obvious the energy accumulation and dissipation.The closer the excitation frequency is to the resonance frequency,the greater the distance between the vortex core and the baffle,and the energy intensity around the baffle increases as the frequency increases.The time history of the wall pressure P and the vorticity Q at the position of the vortex core at the baffle is regular,,and the ratio of P_max to Q_max decreases with the increase of the excitation frequency.（3）Design of cross linkage baffle and analysis of wave suppression characteristics.The structural design scheme of cross linkage baffle fuel tank is proposed.Compare the sloshing characteristics of fuel tank under different braking acceleration and different filling rate.According to the evolution mechanism of vortex flow structure of fuel tank under braking condition,the wave suppression characteristics of baffle are analyzed.The results show that the fuel tank has only non impact ordinary hydrodynamic pressure with low pressure peak at low braking acceleration.With the increase of braking acceleration,the jet velocity of oil through the baffle hole increases,the nonlinear phenomenon caused by impacting the liquid surface intensifies,and the impact pulse pressure is generated.And the time of the peak value of impulse pressure and non impulse ordinary hydrodynamic pressure is becoming smaller and smaller.With the increase of the filling rate of the fuel tank,the jet velocity of the oil passing through the baffle hole decreases and the intensity of shaking decreases.The filling rate is 25%and 50%,and there is only non impact ordinary hydrodynamic pressure.When the filling rate is 75%and 90%,there are impulse pressure and non impulse ordinary hydrodynamic pressure.The growth rate of impact pressure is the lowest at 75%liquid filling rate.The vortex structure generated near the cross linkage baffle changes the flow field structure,reduces the oil climbing speed and achieves the effect of restraining sloshing.