IMPACT OF LIQUID SLOSHING ON THE VEHICLE TANK DESIGN

Several standards exist for the design and safety regulations for vehicles carrying dangerous goods. These standards apply to cargo tanks used for highway transportation. The increase in the reenhouse gases emission and governmental restrictions, research takes towards the use of lighter materials (Al, Mg, plastics, composites, etc.,) to reduce weight, fuel consumption and CO2 emission. These standards describe basic requirements for design, construction, testing, inspection, re-testing, qualification and maintenance, and identification aspects of such tanks. The container shapes most commonly associated with road tankers are the rectangular tank, the horizontal cylinder, the sphere, the cylindrical tank of trapezoidal cross section, the paraboloid and the conical tank for special vehicles. The standards also address the design requirements for joints, manholes, openings, piping, valves and fittings, supports, circumferential reinforcements and accident damage protections. However, the standards do not address the adverse influence of liquid sloshing forces in partially-filled tanks on the stability and handling of tank vehicles. In general, the tanks are designed based on their structural integrity rather than on vehicle system stability considerations. The forces and the moments resulting from the interactions between the liquid and the vehicle, in several maneuver situations as turning and braking in turning can make considerable variations of the liquid load shift and will cause high local pressures and dangerous stress on the tank structure. In this study, analytical and numerical liquid models are formulated based on the Navier-Stokes equations with some assumptions for the analytical model. The pressure forces will be calculated and compared to tensile strength for several materials proprieties. The configuration of the free surface of the liquid used in this study is illustrated in Figure 1. The Figure 2 highlights the numerical modeling of the free surface subject to lateral acceleration and longitudinal acceleration respectively.