Baffle Design Analysis for a Road Tanker: Transient Fluid Slosh Approach

Baffles are known to help reduce the amplitude of fluid slosh in partly filled tanks, particularly during braking and acceleration. The transient fluid slosh approach is proposed to evaluate the effectiveness of baffles designs. A computational fluid dynamic (CFD) fluid slosh model is developed using the VOF (volume of fluid) technique coupled with a Navier-Stokes solver. The validity of the model is demonstrated using the experimental data acquired with a scale model tank. The validated CFD model is subsequently formulated for a full scale tank and simulations are performed under excitations idealizing the straight-line braking maneuvers to investigate the anti-slosh role of four different transverse baffles concepts. The fluid slosh responses are analyzed in terms of the fundamental slosh frequency, and the resulting forces and moments under different fill volumes of liquid cargos of constant load. The simulation results show that the natural frequency and peak magnitudes of slosh forces and moments strongly depend on the baffle design and the fill volume. The transverse baffles yield significantly higher longitudinal mode slosh frequency, and lower longitudinal force and pitch moment. The shape and locations of baffles orifices play significant role in suppressing the transient fluid slosh. Highly effective anti-slosh effect is also observed for the partial baffle designs under higher fill levels.