Study On The Sloshing Of Fuel Tank And Its Noise Control

The noise in the vehicle is an important factor affecting the ride comfort.With the reduction of the traditional noise,such as engine noise,intake and exhaust noise,and the application and popularization of the engine start-stop,HEV,PHEV and other technologies,the sloshing noise of the fuel tank,as one of the internal noise sources of the vehicle,is gradually highlighted,which directly affects the initial evaluation and the general impression of the consumers for the automobile.In this paper,the fuel tank of a passenger car is taken as the research object.On the basis of summarizing the research status of the fuel tank sloshing and noise at home and abroad,the analysis and optimization are carried out from the point of view of simulation and experiment.The main research work and conclusions are as follows:(1)The subjective evaluation of the sloshing noise of different filling rates and different driving conditions was carried out for the fuel tank in the entire vehicle state.The results show that the sloshing noise in the creep driving condition of the 100% filling rate is the most serious.The following simulation and experiment were conducted in this filling rate and driving condition.(2)Based on the STAR-CCM+ software,the sloshing CFD model of the fuel tank was established.The sloshing simulations of the fuel tank with different filling rates were carried out in the creep driving condition.The three-dimensional motion view and the maximum pressure distribution of the fuel tank wall with the time change show that the fuel tank sloshing is the most violent in the 100% filling state,which is in accordance with the subjective evaluation results,and also verifies the accuracy of the simulation model.(3)Based on the Abaqus software,the fuel tank FE model is established.Through the coupling with the STAR-CCM+ software,the fuel tank sloshing and structural dynamics simulation were carried out for the fuel tanks with or without baffles and three different types of structural baffles.The pressure and vibration acceleration of the wall of the fuel tank under the different baffles are obtained.The results show that the maximum pressure on the wall of the fuel tank and the vibration acceleration of the four monitoring points are significantly reduced after the installation of the baffles,and the peak value of the vibration acceleration is reduced by more than 50%.The vibration acceleration peaks at the four monitoring points for the three types of baffles are both the left front monitoring point is the largest and the right rear is the smallest.The baffle 3 was selected to install on the fuel tank for the subsequent vehicle test.(4)On the basis of the analysis of the sloshing noise transmission path of the fuel tank,the experiment of the fuel tank installed with the baffle 3 was carried out.The vibration acceleration of the fuel tank body,the straps and the body,as well as the sound pressure in the cabin and the tank side under the creep driving condition were obtained,The vibration acceleration of the fuel tank body is compared with the simulation value,which is in good agreement,both of them have the largest vibrations on the left front side and the smallest vibrations on the right rear side,For the vibration accelerations of the straps and vibration isolation pads,their influence on the vibration acceleration transmission was analyzed,and the noise analysis is carried out in the near field of the fuel tank and the cabin of the crew.(5)According to the simulation and experimental results,the improved design of the fuel tank structure was made in terms of baffles,fuel tank shell,and vibration isolation cushions.To verify the improvement effect,comparisons were made before and after optimization through fuel sloshing and structural dynamics simulation.The vibration acceleration of the fuel tank wall after optimization was significantly reduced,especially in the right rear monitoring point,the Z-direction vibration acceleration was reduced by 30.9%,and the reliability and effectiveness of the optimization was confirmed from the simulation point of view.