Simulation Research On Lateral Liquid Sloshing In Tank Vehicles

As a kind of common mobile pressure vessel,tank vehicle is often used as a transport vehicle for dangerous chemicals,easily leading to catastrophic accidents.The loads of tank vehicles are mostly liquid or liquefied gas.When the motion state of a tractor changes,such as turning,dodge,lane change and so on,the liquid in the tank will surge under the action of inertia force,producing the lateral sloshing load and rollover torque to the tank.Besides,the shift of tank gravity also occurs.All of them will reduce the vehicle roll stability,easily causing the rollover accident.Therefore,the research on lateral liquid sloshing in tank vehicles is of great significance to improve the roll stability and ensure the safety of tank vehicles.The specific research contents are as follows:(1)The numerical simulation method and model are determined.Based on the fluid calculation software FLUENT,the simulation model of the lateral liquid sloshing of the tank vehicle is built and the software parameters are determined.By using the dynamic reference coordinate system and the fluid acceleration method,the lateral liquid sloshing in the tank can be realized and the equivalence of the twomethods is verified by a numerical example.Compared with the measured liquid sloshing frequency,the difference between the numerical calculation results and the test results is less than 7.4%,indicating that the numerical model is reliable.(2)The numerical simulation of the influence by liquid sloshing on liquid load parameters in the tank is performed.The tank model is selected to simulate the calculation of lateral liquid sloshing and the liquid load parameters are monitored which are compared with the estimated value of quasi-static method(QS).The results show that the transient liquid sloshing produces additional force and torque and increase the centroid shift.However,this effect will decrease with the increase of filling rate.(3)The numerical simulation of the influence by liquid sloshing on the roll stability of tank vehicle is performed.The numerical simulation and quasi-static method are used to solve the rollover threshold respectively.The results show that the filling rate of 0.5~0.6 is the most dangerous filling interval and the additional torque produced by the transient liquid sloshing has the strongest influence on the rollover threshold.The tank vehicle owning high filling rate can improve the roll stability.(4)The numerical simulation of the influence by tank cross-section shapes on the roll stability of tank vehicle is performed.The displacements,sloshing force and rollover torque of liquid mass indifferent cross-section tanks are compared.The results show that the cross-section length is the key factor to distinguish the numerical size of liquid rollover torque in different cross-section tanks.In order to improve the stability of the tank vehicle,the best choice is the square cross-section tank.(5)The numerical simulation of the influence by set of the anti-wave plate on the roll stability of tank vehicle is performed.Lateral liquid sloshing in the tank is achieved and the change of force and torque caused by liquid is monitored without the anti-wave plate and under the change of the anti-wave plate position.The results show that to a certain extent,the set of anti-wave plate reduces the effect of the transient liquid sloshing in the tank.The larger effective anti-wave area of the anti-wave plate below the liquid level makes the anti-wave effect better.