Investigation On Liquid Sloshing Dynamics In Partially Filled Tank Vehicles

Liquid sloshing is a complex phenomenon and is associated with the field of aerospace,ship and pavement transportation.In the field of pavement transportation,tank vehicles have become the main tool for transportation of petroleum,liquefied natural gas and dangerous chemicals.Tank vehicles are often partially filled due to wide variations in mass density of the cargo and regulatory axle load limits.Liquid sloshing under maneuver induced excitations may have adverse effect on tank vehicles: on the one hand,the loads produced by liquid sloshing can cause tank structural damage;on the other hand,liquid sloshing will change the load distribution on axle,cause additional sloshing forces and moments and thus affect the stability of tank vehicles.Therefore,numerical research on liquid sloshing and the research on anti-slosh devices in tank vehicles have important academic value and practical engineering significance.Firstly,set up an experimental platform of liquid sloshing for the investigation of liquid sloshing in partially filled tanks with or without an elastic membrane(airbag).The experiment consists of two parts: one is the liquid sloshing in the longitudinal direction and another one is the liquid sloshing in the lateral direction.Hence the tank is subjected to harmonic acceleration with different amplitudes and frequencies in both longitudinal and lateral direction.The measured data is studied by spectral analysis to confirm the dominant frequency component,and to confirm the relationship between the dominant frequency and the excitation frequency.The anti-sloshing performance of the elastic membrane(airbag)is evaluated by comparing the measured data for the partially filled tank with or without an elastic membrane.Secondly,a 3-D liquid slosh dynamic model is established for partially filled tank vehicles when subject to turning and braking maneuvers.The validity of the slosh model is evaluated using the measured data in terms of slosh forces and moments.The model results show reasonable good agreements with the measured data.The influence of the geometry parameters(baffle curvature,opening area,opening shape and the inclination of baffle)of baffles on liquid slosh is evaluated.Besides,the formation mechanism of air pressure was proposed under medium or high fill ratios and the effect of air pressure on suppressing liquid sloshing is also investigated.For the first time,a new kind of flexible damping device—an elastic membrane—is proposed.The corresponding fluid structural interaction(FSI)model is established for liquid sloshing in a tank with the liquid free surface covered by an elastic membrane.A series of tensile experiments are conducted to confirm the constitutive relation of material used for the membrane(airbag).The Yeoh hyperelastic material model is established to meet the constitutive relation of the membrane material.The Yeoh model is converted into the FSI model for preparation of model validation.The validity of the FSI model is evaluated using the measured data in terms of sloshing forces and moments.The model results show reasonable god agreements with the measured data.At last,the effect of the pre-tension of membrane,the mounted location of membrane and the magnitude of air pressure is investigated in a full-scale tank by the Application of the established fluid structural interaction model.The research results of this dissertation will contribute to the understanding of liquid sloshing in partially filled tanks.As a new kind of anti-sloshing device,the elastic membrane will contribute to the investigation of liquid sloshing control.