Dynamic Lateral Sloshing Dynamics And Model Study Of Liquid Tank Trucks

Vehicle lateral instability caused by the liquid sloshing is a crucial threat for the driving safety.The system presents to be highly nonlinear characteristic due to the coupling interaction between liquid and vehicle subsystem.A compact roll dynamic model,which used to further investigate the vehicle roll stability,is established based on the integrated equivalent mechanical model in this paper,focusing more attention on the applicability and its improvements of this equivalent mechanical model in the case of liquid nonlinear sloshing.First of all,study on the roll dynamics performance for the tank truck based on equivalent mechanical model method.The integrated trammel pendulum model for liquid-vehicle coupling dynamics model in the view of Lagrange method,the roll coupling mechanism is addressed based on the integrated trammel pendulum model from the perspective of frequency angle.The effects of the LTR on the vehicle roll stability under a multi-parameter case are revealed,and the roles of suspension system play on the vehicle roll dynamic control are also discussed.Simulations results demonstrate that the coupling effects between the liquid sloshing in the partly-filled tank and vehicle roll dynamic are determined by the tank interface shape and liquid filling level,and the coupling effects are significant and irregular.The first-order modal and the second-order modal of the vehicle roll dynamic all are important,but the first-order modal is critical,which should be high improve as far as possible in vehicle design.The partly-filled tank truck posing the small oval tank appears more satisfying roll stability in the common liquid filled level and steering system frequency,while the half-filled tank truck with large oval tank obtains the similar roll stability in the higher liquid filled level.Secondly,evaluations research on predictive accuracy of trammel pendulum model approach in the liquid nonlinear sloshing condition.The liquid sloshing CFD model is created firstly in the fluid simulation platform ANSYS/Fluent,the comparisons between the trammel pendulum model and CFD model are conducted to evaluate the predictive accuracy of equivalent mechanical model based on the root mean square error,sensitivity method and sloshing moment time response etc.The effect mechanism of ellipticity,liquid filling rate and excitation frequency on the predictive accuracy of trammel pendulum model is discussed,and the novel investigation approaches and thoughts are further proposed.Results illustrate that the interaction coupling among tank body section shape,liquid filling rate and lateral acceleration produced by the steering operation condition has significant effect on the predictive accuracy of presented equivalent mechanical model in the actual vehicle operation conditions.In addition,the predictive accuracy of trammel pendulum model is lower compared to the equivalent mechanical model with characteristics of the large ellipticity and higher liquid filling rate relatively in the liquid nonlinear sloshing.Finally,improvements in adaptability and accuracy of trammel pendulum model.The improved model motion equations are induced by the Lagrange method,which are validated with the simulated platform.The angle and angular velocity of the liquid sloshing are analyzed based on the improved trammel pendulum model,the predictive accuracy of two improved liquid-vehicle models are also evaluated.Simulations show that the developed model creates the rather satisfying swing responses and predictive accuracy,validating the effectiveness of the proposed trammel pendulum model.