CFD Analysis of Fuel Sloshing in a Cylindrical Tank with and Without Baffles Under Linear Acceleration

Abstract

The phenomenon of sloshing can be understood as any motion of liquid surface. When any partially filled container is disturbed by any external forces, sloshing occurs for example a tank containing fluid put on a moving vehicle. But for occurrence of sloshing the container must have a free surface of liquid. The sloshing causes additional sloshing forces and moments which finally changes the system dynamics and stability. For a moving vehicle this may affect the steering and braking performance as the liquid interacts with the walls of the container. The sloshing phenomenon includes various fields such as propellant slosh in rockets and space crafts, cargo ships and also the trucks which carry different type of fluids. To suppress the sloshing and to limit the effects generated baffles are used. They change the fluid’s natural frequency and thus omits the chances of occurrence of resonance.
The present study aims towards the design of different types of transverse baffles and their effects in reducing the magnitudes and variation of forces and moments generated in a cylindrical tank partially filled with gasoline subjected to linear acceleration and deceleration. A 3-D transient analysis of the tank was carried out for 20 seconds using ANSYS-FLUENT software at two different fill levels. Volume of Fluid (VOF) method was used to track the surface. The study shows that baffles with more no of holes on their surface reduces the longitudinal forces most effectively but vertical force are reduced with baffles having a single central cavity. For controlling the moments also baffles with single cavity proved to be more effective.