Page 33 - 01

SLOSHING IN A T-BAFFLED RECTANGULAR STORAGE TANK 31
NUMERICAL STUDY FOR 2–D PROBLEMS

0.01 T1
0.008 T2
0.006 T3
T4

Pmax / gL0.004

0.002

0

-0.0020 0.2 0.4 0.6 0.8 1
hB / h

Figure 17. The mean maximum pressures in a vertical baffled tank, θ0 = 40.

4. Conclusions

In this study, the effects of the vertical baffle and the T-shape baffle are investigated based on
the liquid sloshing in a moving partially filled 2D-ractangular tank. A numerical algorithm
based on the volume of fluid technique (VOF) is used to study the non-linear behaviour of
liquid sloshing. The numerical model solves the complete Navier-Stokes equations in primitive
variables by using of finite difference approximations with the moving coordinate system. The
ratio of the baffle height to the initial liquid depth has been changed in the range of 0 ≤ hB / h ≤
1.0. For all cases, the fluid depth (h) is 75% of the tank height. The present time simulations of
the pressure at T1 give a reasonable agreement with the experimental results of Akyildiz and
Unal (2005), (2006). The little variations in the data are due to the ineptness of the
experimental set up and the input parameters.

In the cases of the vertical and T-baffled tank, at T4, the roof impact of the liquid doesn’t occur
at any instant beyond the baffle height of hB / h ≥ 0.65. As hB / h increases, the value of the
maximum free surface elevation keeps decreasing and does not reach the top wall due to the
suppression of the liquid sloshing by the hydrodynamic damping of the baffles including the
blockage effects and the viscosity of baffle walls. The blockage effect of the vertical baffle on
the liquid convection is predominant to the tip vortex and the strength of the vortex by liquid
flow separation from the vertical baffle tip become weaker as hB / h increases. The T-shape
baffles also represent the shallow water effect and the inertial forces are not enough to propel
the liquid to reach to the top wall of the tank. On the other hand, the maximum overturning
moment for the T-baffled case would be much smaller.

Since the transducers of T3 and T4 locate above the initial free surface height, the values of
pressure at these transducers are obtained by net liquid impact, resulting in the dynamic
pressures. At T1, the static pressure is mainly predominant over the dynamic pressure. As hB /
h and the rolling amplitude increase continuously, Pmax diminishes slowly for hB / h < 0.8 and
rapidly for hB / h ≥ 0.8. Then, It can be concluded that a vertical baffle for hB / h < 0.8 would

Sayı 1, 2014 GiDB|DERGi