Experimental Study On Sloshing Dynamics Of Rectangular Liquid Filled Tank Under Horizontal Excitation

Liquid filled system can be seen everywhere in daily life and engineering,such as liquid tank,oil tank,fuel tank,aqueduct,reservoir,etc..Unlike solid,liquid filled systems tend to have larger hidden safety trouble during the application.Under the external excitation,the liquid tank is easy to produce sustained oscillation,change the wall pressure distribution,then produce the charging sloshing force and shaking moment to the constraint structure,which will have greatly impact on the overall stability of the system.Therefore,it is of great application value to study the dynamic characteristics of liquid sloshing in liquid filled system under external excitation.With the background of the medicine boom sprayer,this paper selects the rectangular tank as research object.Through the experiment,the mechanical characteristics of liquid filled rectangular tank under external excitation were studied.In order to obtain the liquid sloshing force and shaking moment caused by transverse sway,this paper designed two schemes: lateral force and vertical force test;considering the inertia force influence of medicine cabinet and bracket,this article made the research respectively from the charging system of whole and the pure liquid;and pay more attention on the impact factors that influence the mechanical properties of liquid filled system,such as the carrier liquid depth,excitation frequency and excitation amplitude.Through the processing and analysis of test data,and the influence rule of liquid depth,excitation frequency and excitation amplitude on sloshing force and torque of liquid filled system were obtained.The experiment results were shown as followed:(1)The lateral force and vertical force of liquid filling system have similar characteristics with the increase of frequency: when the excitation frequency increases continuously,the forces increases gradually;and during the first-order natural frequency oscillation,the measured forces reach the maximum,show the significant nonlinear;when they are away from the natural frequency,the overall forces value of liquid filling system showed the first sharp decline after rising trend,while the pure liquid force value decreased after the trend.(2)The lateral force and vertical force of the liquid filled system increase with the increase of liquid depth,but with the increase of the depth of the liquid,the frequency distribution of the extreme value of the lateral force decreases.(3)The lateral force and vertical force of the liquid filled system increase with the increase of the excitation amplitude,but with the increase of the excitation amplitude,the frequency distribution of the extreme value of the transverse force is not obvious.The equivalent mechanical model of liquid sloshing was introduced,through the method to obtain the equivalent mechanical model parameters by frequency response function,this paper got the frequency response function of the charging system,and fit the experimental data with the two order equivalent model,and reached a good agreement.The relationship between the first order sloshing mass,the position of sloshing mass and the equivalent spring stiffness of the equivalent model of liquid sloshing in rectangular tanks is summarized.