Analysis of the Effect of Variation of Baffle Height on the Liquid Sloshing In the Tank with CFD Approach

Suresh Patil. G. L et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 12, (Part - 2) December 2015, pp.115-121
www.ijera.com 115|P a g e
Analysis of the Effect of Variation of Baffle Height on the Liquid
Sloshing In the Tank with CFD Approach
Suresh Patil. G. L, Dr. B.Anjaneya Prasad, Dr. D. Maheswar, Dr. S. Chakradhar
Goud
Research scholar J. N. T. University Hyderabad
Professor (Mech Dpet), & DE J. N. T. University Hyderabad
Principal KMIT Hyderabad
Principal Sana Engineering College Kodad, Telangana
Abstract
Sloshing is a common physical phenomenon which occurs in moving tanks with contained liquid masses, such
as liquid cargo carriers, rockets, aircrafts, and the seismically excited storage tanks, dams, reactors, and nuclear
vessels. The sloshing frequencies of contained liquid are essential in the analysis and design of the liquid tanks
and the associated structures. In this paper an attempt made with the VOF model and considered with
immiscible fluids by solving a single set of momentum equations and tracking the volume fraction of each of the
fluids throughout the domain. Further investigated the effect of the vertical baffle heights on the liquid sloshing
in a three-dimensional (3D) rectangular tank. studied dynamic analysis of sloshing in rectangular tanks with
multiple vertical baffles. ANSYS-CFX software was used to study this dynamic analysis subjected to random
excitations including earthquake induced motions. analytically estimated hydrodynamic damping ratio for liquid
sloshing phenomenon in a partially filled rectangular tank for baffles. They used the velocity potential
formulation and linear wave theory for analytic calculations.
Key words: sloshing, CFD, VOF model
I. INTRODUCTION
The present work is to examine computationally
the effect of variation of baffle height on the liquid
sloshing in the tank, The vertical height of the baffle
was varied relative to the initial liquid fill level.. The
analysis shows that if the tank is subjected to
excitation Frequency, liquid sloshing will become
extreme and wall forces will be intensified. Result
shows that after a certain height (critical height) of
baffle, the liquid does not reach at roof top and when
baffle height is equal to liquid fill level, almost linear
behavior of the free surface is observed in each
section.
II. METHODOLOGY
In this case two sub cases with vertical baffle
height of 0.12m and 0.38m is considered. 0.12 m
vertical baffle height is below the optimum level of
liquid in the tank of 60% volume fraction and 0.38m
height is at the surface level of the liquid in the tank
with 60% volume fraction.CASE I: Vertical baffle
height of 0.12m :The below figure shows the cad
layout of the tank with two baffles of same 0.12 m
vertical height, the height of the baffles was well
below the level of liquid in the tank of 60% volume
fraction.
2.1CAD model of the tank with two baffles of
0.12m vertical height
Wall boundary conditions were assumed for
baffles while doing the analysis and fluid domain was
chosen for the interior of the tank.
2.2 Meshed model of the tank with baffles
Mesh report - Table 2.1
Domain Nodes Elements
solid 54144 49266
RESEARCH ARTICLE OPEN ACCESS

CASE II: Vertical baffle height of 0.38.:-
2.3 CAD model of the tank with two baffles of
0.38m vertical height
2.4 Meshed model of the tank with baffles of
vertical height 0.38m
Mesh report –Table 2.2
Domain Nodes Elements
solid 12096 9963
III. RESULTS AND DISCUSSIONS
Figures 3.1- 3.21 show the liquid sloshing in
tank with two baffles with vertical height of 0.12m
which is below the height of the liquid level in the
tank. Liquid level of 60% volume fraction was
considered in this case which was found to be
optimum from the previous case.Figure below shows
the sloshing of the liquid at 0.01sec for lateral effect
with two baffles, with baffle height of 0.12m there
was no much sloshing was observed.
Fig 3.1: Tank sloshing with vertical baffle height
of 0.12m at 0.01 sec
From the figure, the sloshing at 0.2 sec was
almost the same as that was observed in case 1
without baffle, the vertical height of 0.12m baffle
does not shows much effect on sloshing.
of 0.12m at 0.2 sec
From the figure it can be observed that the liquid
reaches the top of the tank at much less time as in
case of the sloshing in tank without baffles, this was
observed for 0.4sec also.
of 0.12m at 0.3 sec
The sloshing in the tank became more
predominant at 0.4 sec and baffles does not show
much effect on the sloshing, Since the baffles vertical
height was very less the liquid reached the top of the
tank early , as the baffle does not have much stopping
impact on the liquid.
of 0.12m at 0.4 sec
of 0.12m at 0.6 sec
As there is increase in time the sloshing became
more predominant in the tank and vertical heigt of
baffle does not have any impact on the liquid causing
the liquid to reach the top surface of the tank which
was commonly observed for tank with no baffles.

of 0.12m at 0.8 sec
of 0.12m at 1 sec
of 0.12m at 1.2 sec
of 0.12m at 1.4 sec
of 0.12m at 1.6 sec
of 0.12m at 1.8 sec
of 0.12m at 2 sec
of 0.12m at 2.4 sec
of 0.12m at 2.6 sec
of 0.12m at 2.8 sec

of 0.12m at 3 sec
of 0.12m at 3.2 sec
of 0.12m at 3.4 sec
of 0.12m at 3.6 sec
of 0.12m at 3.8 sec
of 0.12m at 4 sec
The pressure distribution caused by liquid
sloshing at different probes is shown in figure. It was
observed that the compression zone is located in the
down right corner of the tank and in the baffle
down. The maximum pressure in the tank was
observed to be approximately 400Pa at 0.04sec and
was found to be gradually decreased with increase in
time to minimum pressure or no pressure at 2 sec and
75pa at 4sec.
Fig 3.22: Variation of pressure with respect to
time
The figure below shows the variation of amplitude
with frequency maximum amplitude of the liquid
sloshing wave was found to be 40db and was
decreasing with increase in frequency.
Fig 3.23: Variation of Amplitude with respect to
Frequency
3.24 Velocity vectors of liquid sloshing inside tank
for 1.2m vertical height of the baffles

3.25 Velocity streamlines of liquid sloshing inside
tank for 1.2m vertical height of the baffles
CASE II: Vertical baffle height of 0.38m
Vertical baffle height of 0.38m was considered
in this case fr 60% volume fraction of liquid and two
baffles, The critical baffle height of the baffle was
obtained from this analysis,The vertical height of the
baffle was found to be a critical case in case of liquid
sloshing in tanks, It was found that as the height of
the baffle increases the blocking effect on the liquid
in reaching the top of the tank and avoiding the
impact of liquid on the top face of the tank.
3.26 Tank sloshing with vertical baffle height of
0.38m at 0.01 sec
0.38m at 0.1sec
0.38m at 0.2sec
0.38m at 0.35sec
0.38m at 0.4sec
0.38m at 0.5sec
0.38m at 0.6sec
0.38m at 0.7sec
0.38m at 0.8sec

0.38m at 0.9sec
0.38m at 1.2sec
0.38m at 1.3sec
0.38m at 1.4sec
0.38m at 1.6sec
0.38m at 1.8sec
0.38m at 3sec.
The critical baffle height is hB/h=0.3 beyond
which liquid does not reach the roof of the tank at
any instant and consequently does not lead to roof
impact. Effect of the vertical baffle height on the
liquid sloshing in a three-dimensional rectangular
tank.
0.38m at 4sec
Figure shows the variation of pressure with time for
0.38m of baffle height. The variation of pressure with
time was converse as in case of vertical baffle height
of 0.12m , It was observed to be maximum at 0.2 sec
with magnitude of 600Pa approx and then showed
irregular variation due to the blocking effect of the
baffle as the height of the baffle is more then the
liquid level, which restricted the liquid to reach the
top surface of the tank.
3.43 Variation of pressure with respect to time for
0.38m vertical baffle height

3.44 Variation of Amplitude with frequency
The liquid no longer goes over the baffle and the
liquid sloshing is restricted to within half of the tank
and an almost linear behavior of the free surface is
observed in each section. The vortex generated by the
flow separation from the baffle tip becomes weaker
and smaller with increasing baffle height, leading to a
diminished damping effect of the tip vortex on the
liquid sloshing.
3.55 Velocity vectors of the liquid for 0.38m
vertical baffle height
The figure below shows the streamline of the
liquid in the tank, the vortex shedding was found at
the tip of the baffle, which was more as in case of the
vertical baffle height of 0.12m.
3.56 Flow streamlines across the tank with baffles.
IV. CONCLUSIONS AND FUTURE
SCOPE
Pressure comparisons in both cases it is found
that the vertical baffle height of 0.38m was optimum.
As vertical height increases the free surface behavior
of liquid is found to be stable without reaching top
surface of the tank. As the vertical baffle height
increases, the blockage effect of the vertical baffle on
the liquid convection is predominant to the tip vortex.
Free surface elevation was found to be decrease as
height of the baffle increases. It was observed that the
vertical baffle is a more effective tool in reducing the
sloshing amplitude. As the impact pressure of the
liquid increase on the baffles with increase in vertical
height, because of this impact the thickness variation
can be considered as an extension for the research.
Impact pressures can vary by changing tank design
by keeping the volume constant.
REFERENCES
[1.] J.H. Jung, H.S.Yoon, C.Y.Lee, S.C.Shin
(2012), “Effect of the vertical baffle height
on the liquid sloshing in a three-dimensional
rectangular tank”, Ocean Engineering. Vol
44: 79–89
[2.] Mahmood Hosseini, Hamidreza
Vosoughifar, Pegah Farshadmanesh (2013),
“Simplified Dynamic Analysis of Sloshing
in Rectangular Tanks with Multiple Vertical
Baffles”, Journal of Water Sciences
Research, ISSN: 2251-7405 eISSN: 2251-
7413 Vol.5, No.1: 19-30.
[3.] M. A. Goudarzi · S. R. Sabbagh-Yazdi · W.
Marx, (2010), “Investigation of sloshing
damping in baffled rectangular tanks
subjected to the dynamic excitation”, Bull
Earthquake Eng. Vol 8:1055–1072.

Analysis of the Effect of Variation of Baffle Height on the Liquid Sloshing In the Tank with CFD Approach

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