CFD Analysis of Sloshing in the Fuel Tank of a Heavy Vehicle with Emergency Braking System

Abstract

Liquid sloshing, which occurs in all accelerating and liquid-carrying vehicles, is of great importance, especially in the automotive and aerospace industries. Large-scale fluid sloshing causes both operational and safety problems in vehicles. In this study, the fuel tank of a heavy vehicle with an emergency braking system is designed in three dimensions, and liquid sloshing in the fuel tank is investigated by CFD analysis meth-od. VOF solution method, k-ԑ turbulence model, and PISO solution algorithm are used in the study. In the analysis of liquid sloshing, it is assumed that the vehicle is traveling at a certain speed, decelerates and stops with emergency braking, and remains station-ary for a while. The braking scenario and boundary conditions are based on test data from a heavy vehicle manufacturer. The designed fuel tank with a capacity of 207.6 li-ters was analyzed at 25%, 50%, and 60% diesel fuel filling levels in 6 different cases with and without anti-slosh baffles. Four virtual sensors were placed on the side wall of the fuel tank in the direction of vehicle movement, and time-dependent pressure changes were analyzed for all cases. In addition, the fuel volume ratio in all cases is visualized and presented for specific time steps. With the use of anti-slosh baffles, the maximum pressure, the rate of pressure increase, and the liquid sloshing were reduced by a factor of 2-3 for different cases. With the design of the fuel tank using anti-slosh baffles, instantaneous interruptions in the fuel system are prevented. Reducing the im-pact pressures on the tank walls is expected to positively affect noise, vibration, and stability problems.