Numerical Simulation Of Liquid Sloshing And Study Of The Influence Of Inertia Force Loading Methods On The Strength Of Tank Containers

With the economic globalization and rapid development of petrochemical industry,more and more liquefied petroleum gas and other liquefied gases are demanded in all countries of the world.Having the features as being large in capacity and low-cost in transport, tank container was widely used for transporting liquefied gases.Loadings applied on the container in use include internal pressure or external pressure load,inertial force and impact force caused by liquid sloshing.Tank container belongs the most dangerous Class III pressure vessel and special requirements related to the structure,application and security have to be considered.Therefore,it is necessary to study the strength of the container under inertial forces which could be caused by the sloshing of the contained liquid.First,a finite element model was established for a tank container of 1CC, the inertial force of liquid was treated as a static load and applied on the container as the body force with the equivalent quality method or surface force with the average pressure method. Strength check for room-temperature and low-temperature environments was performed based on relevant standards. It was found that under the different working conditions,the strength of container shell is mainly controlled by internal pressure, while the frame is mainly affected by the inertial force.Secondly, liquid sloshing was numerically simulated with the emphasis on the changes of impact force, pressure and Reynolds Number.It was found that the maximum pressure produced by liquid sloshing is much larger than the initial static pressure and severe turbulence in flow field is produced upon sloshing.A formula for calculating the maximum impact on front head under the action of the inertia force was regressed as a function of acceleration, filling rate, liquid density and tank volume with the accuracy of more than 95%.Finally,the inertial force of liquid was treated as a dynamic load and the strength of the container was calculated and checked.Three different methods, namely equivalent quality method,average pressure method and impact load method,for loading the liquid inertial force were investigated and compared to see their effects on the container's stress intensity. It was found that for the container shell, different loading methods give different results.For the frame, however,the former two methods yields very close results, but the third method significantly raises the stress intensity.