Research On Equivalent Mechanical Liquid Sloshing Model Of Tank Truck

Liquid tank vehicles are the main means of transporting liquid cargo and have made an important contribution to economic development.The rapid development of advanced driver assistance systems and electronic stability control systems has greatly improved the stability of passenger cars,but the stability of heavy-duty tank vehicles still has serious problems and brings a lot of danger to road transport.Unlike vehicles that transport solid cargo,tank vehicles are more prone to rollovers,rear-end collisions,etc.due to the coupling of liquid sloshing in the tank and the movement of the vehicle.Therefore,it is very important to study the liquid sloshing in the tank.In this paper,the equivalent mechanical model method is used to study the liquid sloshing in the tank with the elliptical cross section,and the lateral and longitudinal sloshing models of the equivalent mechanical liquid are improved and optimized respectively.In the study of the lateral sloshing of liquid in the tank,the trammel pendulum model was briefly introduced and compared with the CFD simulation results to evaluate its prediction accuracy.Through evaluation,it is found that the trammel pendulum model is difficult to adapt to the variation of ellipticity and liquid-fill level in a large range.The prediction effect is not ideal under the conditions of higher liquid-fill level and larger ellipticity.Aiming at the above problems,this paper proposes a multi-mass trammel pendulum model and derives its dynamic equation based on the Lagrangian method.For the sake of convenience,this paper applies the parameters to the double mass trammel pendulum model,the simplest form of the multi-mass trammel pendulum model.The CFD simulation results were used as evaluation criteria to fit the double-mass trammel scale swing arm length,slosh mass,mass ratio of the two liquid pendulums and their length of spacing,and finally represent them as functions represented by ellipticity and liquid-fill level.Finally,by comparing with the CFD results,the time domain response and RMSE results of the double mass trammel pendulum model and the trammel pendulum model are evaluated.The results show that the conditions of various excitation frequencies,ellipticity of the tank body and liquid filling ratio are observed.Under the double mass trammel pendulum model,the sloshing of the liquid can be predicted more effectively.Especially in the actual working conditions of high liquid-fill level,the dualmass elliptical pendulum model has better prediction accuracy.In the study of the longitudinal sloshing of the liquid in the tank,the study of the undamped equivalent spring mass model based on the shrinkage experiment shows that the increase of the damping effect can greatly improve the prediction accuracy of the spring mass model,so the spring mass damping is proposed.The RMSE of the oscillating moment of the equivalent mechanical model and CFD simulation is also used as the evaluation standard,and the optimization function represented by the model parameters and aiming at the minimum value of RMSE is established.The iterative operation of the optimization function is solved by the genetic algorithm in Matlab,and the values of the parameters of the model can be obtained.Finally,by using CFD simulation and optimization function to solve the ellipticity and liquid-fill ratio of different tank sections,the values of the model parameters under different working conditions can be obtained.Finally,the models represented by ellipticity and liquid-fill ratio are fitted.The polynomial function relationship of the parameter.Finally,compared with the CFD results,the two models are evaluated by the RMSE of the sloshing moment and the RMSE of the sloshing moment.The results show that the spring mass damping model has better prediction effect under most working conditions.