DOI: 10.5545/sv-jme.2024.1200 75
© The Authors. CC BY 4.0 Int. Licensee: SV-JME  Strojniški vestnik - Journal of Mechanical Engineering   ▪   VOL 71   ▪   NO 3-4   ▪  Y 2025
Impact of Excitation Frequency and Fill Levels  
on Fuel Sloshing in Automotive Tanks
Rajamani Rajagounder  ‒ Jayakrishnan Nampoothiri
Department of Production Engineering, PSG College of Technology, India
 rajamani.vrr@gmail.com
Abstract Fuel sloshing in modern automotive fuel tanks is analyzed in this study to provide a better understanding of fuel system performance. The behaviour 
of sloshing waves was investigated under varying excitation frequencies and fuel fill levels using both experimental and numerical methods. A sinusoidal motion 
was applied to the fuel tank along its transverse axis, and the resulting wave profiles were captured using a digital camera setup. Numerical simulations were 
conducted using the volume of fluid (VOF) model and a user-defined function (UDF) in ANSYS Fluent to predict the sloshing wave profiles. The study reveals 
distinct wave patterns depending on the excitation frequency. Standing and traveling waves were observed at 0.5 Hz and 0.6 Hz, while multiple traveling waves 
with wave collisions occurred at 0.7 Hz. Additionally, increasing the fuel fill level (from 25 % to 60 % of tank height) significantly enhanced the damping of sloshing 
wave oscillations. Regression equations were developed to quantify the relationship between excitation frequency, fill level, and sloshing wave amplitude. These 
findings may contribute to the design of fuel tanks that mitigate sloshing effects and enhance overall vehicle performance.
Keywords liquid sloshing, fuel tank, finite volume analysis, visualization, wave frequency
Highlights
 ▪ Visualized free-surface fuel motion using numerical and experimental methods
 ▪ Identified wave behaviour at 0.7 Hz with strong standing and traveling wave formation
 ▪ Found increased fill levels enhance damping and accelerate wave decay
 ▪ Developed regression models linking frequency and fill level to wave amplitude
1  INTRODUCTION
Fuel sloshing in automotive tanks poses significant challenges, 
particularly in controlling wave behaviour under varying frequencies 
and fill levels [1]. Various studies have aimed to understand the 
dynamic sloshing phenomena and mitigate its effects using different 
modelling techniques, experimental methods, and tank modifications. 
One of the foundational approaches to studying sloshing was 
provided by Faltinsen [2], who developed a nonlinear numerical 
method for two-dimensional flow, offering crucial insights into the 
fluid motion inside a tank under excitation. Expanding further on this, 
Dongming and Pengzhi [3] employed a three-dimensional model to 
examine sloshing dynamics, illustrating the complexities introduced 
by additional spatial dimensions.
Recent advancements have focused on combining computational 
methods with experimental validation to enhance prediction 
accuracy. The volume of fluid (VOF) method, commonly used 
in numerical simulations, has been applied effectively to analyse 
sloshing behaviour under various conditions. Zhao et al. [4] utilized 
this approach to explore nonlinear sloshing in rectangular tanks 
under forced excitation, uncovering the development of standing 
and traveling waves at different frequencies. Similarly, Jin and 
Lin [5] analysed the viscous effects on sloshing, demonstrating 
the importance of accounting for fluid properties when modelling 
dynamic sloshing behaviour. Qiu et al. [6] and Liu et al. [7] used the 
VOF method to study liquid sloshing, finding that higher fill levels 
and first-order natural frequency intensify sloshing forces. Elahi et 
al. [8] and Topçuand Kılıç [9] also developed VOF-based numerical 
models for sloshing simulation. 
Experimental approaches complement numerical methods by 
validating theoretical predictions. For instance, Rajamani et al. [10] 
conducted an experimental study to capture free surface wave profiles 
in a fuel tank subjected to uniform acceleration, and the resulting 
wave profiles were compared with numerical results. Furthermore, 
Babar et al. [11] explored the coupled Eulerian-Lagrangian (CEL) 
method for simulating multiphysics events in automobiles, bridging 
the gap between computational models and real-world applications.
The incorporation of baffles has emerged as an effective method 
to dampen sloshing. Frandsen [12] examined sloshing in tanks with 
an annular baffle, which showed significant suppression of wave 
amplitude. Similarly, Wang et al. [13] demonstrated that multiple 
rigid annular baffles in cylindrical tanks reduce sloshing effects by 
altering the flow dynamics and dissipating energy. Park et al. [14] 
conducted an experimental study on liquid sloshing in a rectangular 
tank with both rigid and flexible baffles, detailing the behaviour of 
free surfaces at different fill levels and excitation frequencies. Wang 
et al. [15] investigated the impact of different baffle configurations 
on liquid sloshing in a partially filled cylindrical tank mounted on a 
truck. The findings indicate that the introduction of baffles enhances 
the fundamental sloshing frequency and decreases the likelihood of 
resonance phenomena in tank vehicles. These findings have led to 
practical applications in automotive fuel tanks, whereby baffles and 
partitions are used to control the liquid motion and enhance vehicle 
stability. Moreover, parametric studies have revealed the influence 
of various factors, such as fill level, excitation frequency, and tank 
geometry, on sloshing behaviour. Gurusamy et al. [16] explored 
shallow water tanks' sloshing dynamics, focusing on the hydraulic 
jumps formed during wave interactions, providing insights into 
wave-breaking mechanisms under certain frequencies. Sanapala et al. 
[17] performed numerical simulations on baffled rectangular tanks, 
highlighting the relationship between baffle height and sloshing 
suppression.
Despite significant advancements in understanding fuel sloshing 
dynamics, challenges remain in accurately predicting sloshing 

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76   ▪   SV-JME   ▪   VOL 71   ▪   NO 3-4 ▪   Y 2025
behaviour under varying operating conditions and improving 
mitigation techniques. Current models often overlook the interplay 
between multiple factors affecting sloshing, leading to suboptimal 
designs. Therefore, this study made an attempt on a comprehensive 
approach that combines experimental validation with numerical 
simulations to explore the effects of excitation frequency and fill 
levels on sloshing in automotive fuel tanks. By integrating innovative 
tank modifications and computational techniques, this research 
aims to enhance prediction accuracy and provide new insights 
for optimizing fuel tank designs. The combined use of numerical 
simulations and experimental methods has significantly advanced 
the understanding of fuel sloshing in automotive tanks. These studies 
not only help mitigate the risks associated with sloshing but also 
contribute to optimizing tank designs for improved vehicle safety and 
performance.
2 METHODS & MATERIALS
2.1  Numerical Simulation
This study uses the VOF method to simulate liquid sloshing, 
implemented in ANSYS FLUENT (V16.2). The governing equations 
for incompressible fluid motion in the tank are described by the 
continuity equation in Eq. (1) and the momentum equation in Eq. (2),
  V 0, (1)
 


 






  
V
t
VV Pg V
2
. (2)  
An open channel flow boundary condition is applied, utilizing 
a first-order upwind scheme for discretizing convective terms. The 
geometric reconstruction scheme determines the cell values at the 
liquid-air interface, represented by volume fractions ( λ), where ‘0’ 
indicates air and ‘1’ indicates liquid. The volume fraction equation is 
expressed as Eq. (3),


 


t
u 0. (3)
The presence of air or liquid in each cell is calculated using Eq. (4),
j
n
j



1
1  , (4)
where n = 2 for two phases fluid flow problems and λ
j
 is the volume 
fraction of j
th
    phase.
The volume fraction equation is solved using explicit time 
formulation. In a two-phase flow problem, the density ( ρ) of liquid in 
each cell is determined using Eq. (5),
     
22 21
1. (5)
The stability of the numerical solution is controlled by the time 
step (∆t) and element size (∆x) which is expressed in terms of 
Courant number (C) given in Eq. (6),
Cu
t
x



. (6) 
The C value is maintained at less than 1 to control the stability 
of the numerical solution. Also, to analyze the effects of random 
vibrations on the fuel tank, sinusoidal motion along the horizontal 
x-axis is applied, represented by Eq. (7),
uX t 
0
 cos. (7)
In ANSYS Fluent software, a user defined function (UDF) with 
the macro DEFINE_CG_MOTION is used to set translation motion 
at the tank's centre of gravity. The quiescent liquid is assigned zero 
velocity and ambient pressure at the surface, while gravitational 
acceleration is applied along a vertical axis. Implicit body force 
treatment enhances the solution convergence. Surface tension effects 
are neglected, and the tank wall is modelled as a rigid structure.
A grid independence study is conducted with three different 
mesh sizes. The total number of cells 90,561, 110,441, and 156,492 
yielding free surface wave amplitudes of 9.43 mm, 10.27 mm, and 
10.31 mm, respectively. Based on accuracy, computational time, and 
memory usage, numerical simulations are performed using 110,441 
quadrilateral cells.
Fig. 1.  Sloshing wave in a tank
Fig. 1 shows the sloshing wave in a tank and its amplitude. The 
natural frequency of the sloshing wave depends upon the fill level 
(h
0
) and tank length (l).  The motion of sloshing wave under gravity 
field can be expressed using Eq. (8) [18],
v
t
u
x







, (8)
where ∂ η/∂x represents the slope of the free surface. 
The magnitude of free surface from mean liquid level ‘ η’ can be 
calculated using linear analytical solution obtained by Faltinsen [2]. 
When the tank is subjected to sinusoidal motion, the magnitude of 
the free surface is given in Eq. (9). The amplitude of the sloshing 
waves obtained from numerical simulations and experimental studies 
is compared with the result of Eq. (9).



 










 














1 21 21
0
0
g
n
l
x
n
l
h
A
n
sinc osh
n nn nn
tC t
g
Ax t    sins in sin.  






1
 (9)
where, n = 0, 1, 2, 3, ….


n
g
n
l
h
n
l
h
2
0
21
2
21
2

   










tan,
C
K
AC
K
n
n
n
nn
n


 

 
22
,, and
K
A
n
l
h
l
l
n
n
n

 










 











 
cosh
() .
21
4
21
1
0
2
The fundamental frequency (f
n
) of the sloshing waves in a partially 
filled tank is given in Eq. (10), 
f
l
h
l
n







1
2
0

 g
tanh .
 (10)
With g = 9.81 m/s
2
, tank length of 370 mm and fill level of 70 
mm, the fundamental frequency of the wave is 1.06 Hz. At this 

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Process and Thermal Engineering
frequency, violent sloshing will occur and the sloshing wave motion 
becomes highly turbulent. To avoid this, the tank is excited below the 
first natural frequency of the sloshing wave. 
2.2  Experimental Studies 
The experimental setup consists of a reciprocating table with a 
slider-crank mechanism, a direct current (DC) motor, a transparent 
composite fuel tank, a speed control unit, and a digital camera, as 
illustrated in Fig. 2a. The computer aided design (CAD) model of 
the bottom portion of the tank is shown in Fig. 2b, while the spatial 
dimensions of the tank are detailed in Fig. 2c. Sinusoidal motion is 
applied using a slider crank with a crank radius of 25 mm, and the 
frequency is adjusted by varying the motor speed.
A transparent fuel tank is fabricated and the front portion of 
the tank is covered with an acrylic sheet for better visibility of the 
sloshing waves. Water mixed with a colouring agent serves as the 
working liquid. A Redlake’s Motion Pro™ CMOS PCI camera with 
a maximum shutter speed of 10,000 fps (frames per seconds) records 
the sloshing waves at 60 fps. Captured images are converted to 
grayscale, and edge detection is employed to identify the liquid-air 
interface.
When using gasoline for experiments, the fuel tank must be sealed 
to prevent fuel vapor leakage. Therefore, water is utilized in this 
study. Kinematic and dynamic similarities in free surface flow are 
maintained using similitude relations based on Reynolds number (Re) 
and Froude number (Fr), as proposed by Abramson and Ransleben  
[19]. 
 
Fig. 2.  a) Experimental setup, b) CAD model of a fuel tank,  
and c) spatial dimensions of a fuel tank
The similitude relation for free surface wave problem is given in 
Eq. (11)
Ft
l
at
l
h
l
X
l
l
t
2
4
2
0
2











,, ,. (11)
From Eq. (11), the non-dimensional number for the amplitude of 
the sloshing wave (H
*
) and time (T
*
) can be expressed as Eqs. (12) 
and (13)
H
h
l
*
, = (12)
Tt
a
l
Tt
n
**
or   () .  (13)
In this study, the results obtained from numerical simulations 
and experimental studies are presented using the non-dimensional 
numbers H
*
 and T
*
. 
3  RESULTS AND DISCUSSION 
The free surface motion of liquid in an automotive fuel tank 
is analysed for different excitation frequencies such as 0.5 Hz,  
0.6 Hz and 0.7 Hz and fill levels (h
0
/H) of 0.25, 0.33, 0.5 and 0.6. 
The formation of sloshing waves and the amplitude of the waves are 
predicted numerically and compared with the experimental results. 
3.1  The Effect of Excitation Frequency on Sloshing Wave Motion
The formation of sloshing waves in a partially filled container 
depends on factors such as tank shape, liquid level, fluid properties, 
and excitation parameters [20]. This study investigates sloshing wave 
behaviour at various oscillation frequencies, specifically at 0.5 Hz, 
0.6 Hz, and 0.7 Hz, comparing numerical results with experimental 
findings in a tank filled to 50 % of its height. Fig. 3a shows the 
initial position of the free surface of a liquid. At 0.5 Hz, Fig. 3 shows 
the evolution of sloshing waves, starting with a standing wave that 
transitions to a traveling wave (Figs. 3b and c), with numerical 
simulations closely aligning with experimental results (Figs. 3d 
to f). At 0.6 Hz, the initial standing wave (Figs. 4a and b) evolves 
into a traveling wave (Figs. 4c), with noticeable differences between 
numerical and experimental wave patterns emerging after 1.6 seconds 
(Figs. 4c and f), indicating a phase lag in oscillation magnitude (Fig. 
6b).
At 0.7 Hz, Fig. 5 depicts the formation of a standing wave, which 
subsequently transforms into multiple traveling waves (Figs. 5a 
and b). The occurrence of two traveling waves colliding results in 
a superimposed wave (Figs. 5c and e), characteristic of bore wave 
patterns. These patterns are evident in the corresponding experimental 
results shown in Figs. 5g to h. The comparative analysis across 
frequencies highlights the complexities of wave dynamics in sloshing 
scenarios, emphasizing the relevance of numerical simulations in 
predicting wave behaviour.
The findings provide insights into sloshing wave dynamics 
across different oscillation frequencies. The transition from standing 
to traveling waves highlights the impact of frequency on wave 
propagation, with higher frequencies facilitating more dynamic 
interactions, such as collisions and superimpositions. The phase 
lag observed at 0.6 Hz indicates potential discrepancies between 
numerical simulations and experimental results, likely due to 
simplified model assumptions and the neglect of surface tension 
effects, which can significantly influence real-world wave behaviour. 
Nevertheless, the alignment of numerical and experimental results 
at lower frequencies suggests that the VOF approach effectively 
captures fundamental sloshing dynamics, establishing its utility in 
predicting sloshing behaviour in fuel tanks. 
Fig. 6a compares the temporal evlolution of the non-dimensional 
amplitude of the free surface of liquid between numerical simulations 
and experimental studies, when the tank undergoes sinusoidal 
motion at 0.5 Hz. At this frequency, the maximum non-dimensional 

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78   ▪   SV-JME   ▪   VOL 71   ▪   NO 3-4 ▪   Y 2025
Fig. 3.  Sloshing wave profiles at 0.5 Hz: numerical results; a) water level at t = 0 s, b) standing wave at t = 0.8 s, c) standing wave at t = 1.5 s;  
and experimental results: d) water level at t = 0 s, e) standing wave at t = 0.8 s, f) standing wave at t = 1.5 s
 
Fig. 4.  Sloshing wave profiles at 0.6 Hz: numerical results; a) standing wave at t = 0.8 s, b) standing wave at t = 1.4 s, c) travelling wave at t = 1.6 s;  
and experimental results: d) standing wave at t = 0.8 s, e) standing wave at t = 1.4 s, and f) travelling wave at t = 1.6 s
amplitude of the sloshing wave (H*) is 0.246 as showed by 
simulations and 0.233 determined from experiments, showing good 
agreement. However, the experimental results exhibit secondary 
wave crest-troughs that are absent in the numerical model.
Similarly, Fig. 6b presents the comparison at an oscillatory 
frequency of 0.6 Hz. The simulated maximum H* values are 0.250, 
while experimental value reach 0.246. Initially, the sloshing wave 
amplitudes align well, but subsequent cycles reveal additional crest-
troughs in the experimental data, which are not predicted by the 
numerical simulations.
Fig. 6c illustrates the temporal evolution of H
*
 at 0.7 Hz. Here, 
the simulated maximum H* values are 0.352 and 0.364 based on 

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experiments. A significant deviation in sloshing wave motion arises 
in the numerical results due to the formation and interaction of 
multiple traveling waves.
The maximum amplitude of sloshing waves (H
*
) from numerical 
simulations and experimental studies is validated against the 
analytical solution provided by Faltinsen [2]. Fig. 7 depicts the 
relationship between the maximum non-dimensional amplitude (H*) 
and the frequency ratio ( ω/ω
n
), showing an increase in amplitude with 
higher excitation frequencies. Regression equations derived from 
standard curve fitting techniques further illustrate this relationship, as 
represented in Fig. 7.
At 0.5 Hz and 0.6 Hz, the numerical and experimental results 
align closely with the analytical solution. However, at 0.7 Hz, 
notable deviations between numerical and experimental findings are 
observed, highlighting limitations in the numerical model at higher 
frequencies. As the tank motion frequency approaches the natural 
frequency of the sloshing wave, the liquid’s free surface experiences 
violent sloshing. Standing waves transition into traveling waves, 
leading to wave collisions that create turbulence. This turbulence 
results in deviations between the amplitudes of sloshing waves 
obtained from numerical and experimental analyzes compared to the 
analytical model.
3.2  The Effect of Fill Level on Amplitude of Sloshing Wave
The effect of fill levels on the amplitude of sloshing waves is 
analyzed using sinusoidal motion applied to the tank, as governed by 
Fig. 5.  Sloshing wave profiles at 0.7 Hz: numerical results; a) standing wave at t = 0.7 s, and traveling waves at b) t = 1.9 s, c) t = 2.5 s, d) t = 3.2 s, e) t = 3.6 s;  
and experimental results: f) standing wave at t = 0.7 s and traveling waves at g) t = 1.9 s, h) t = 2.5 s, i) t = 3.2 s, j) t = 3.6 s

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Eq. (7). An excitation amplitude of 25 mm and a frequency of 0.5 Hz 
are applied. The analysis considers various liquid levels: 25 %, 33 %, 
50 %, and 60 % of the tank height. As the liquid level increases, the 
mass of the liquid absorbing the disturbances also increases, resulting 
in an increased fundamental frequency of the sloshing waves and a 
decrease in wave amplitude.
 
Fig. 6.  Non-dimensional amplitude of sloshing wave for:  
a)  f = 0.5 Hz, b)  f = 0.6 Hz, and c)  f = 0.7 Hz
Fig. 7.  Maximum amplitude of the sloshing wave versus frequency ratio
Fig. 8 compares the amplitude of sloshing wave motion at 
different liquid levels, highlighting changes in the wavelength of free 
surface oscillations as the liquid level increases. Fig. 9 illustrates the 
relationship between the non-dimensional amplitude of the sloshing 
wave ( η/l) and the liquid level ratio (h
0
/H). The study shows that the 
magnitude of the sloshing wave decreases with higher liquid levels. 
At a fill level of 50 %, experimental results deviate by a maximum 
of 18 % from numerical simulations. The formation of multiple 
waves and turbulence in the liquid flow contributes to variations in 
numerical simulation results. A regression equation is formulated to 
estimate the amplitude of the sloshing wave at specified fill levels.
Fig. 8.  Amplitude of the sloshing wave motion at the different fill levels
3.3  The Effect of Fill Level on the Damping of Sloshing Wave 
Oscillations
The damping factor of a sloshing wave in a closed container is 
influenced by the liquid's viscosity, tank size, and fill level.
This study examines the effect of fill level on the damping of free 
surface wave oscillations by applying an acceleration of 1.6 m/s² 
to the tank for 2 seconds, after which the tank is free from external 
excitation. The sloshing wave then oscillates under free vibration, 
and the decay rate of wave oscillations is recorded for fill levels of 
25 %, 33 %, 50 %, and 60 % of the tank height. The amplitudes of the 
sloshing waves for these fill levels are presented in Fig. 10a.
The hydrodynamic damping of the free surface wave is calculated 
using the logarithmic decrement method adopted from Ibrahim [21]. 
The logarithmic decrement ( δ) is determined using Eq. (14).
 







1
n
x
x
r
nr
ln , (14)
where x
r
 is the amplitude of the sloshing wave in any reference cycle 
and x
n+r
 is the amplitude of the sloshing wave after completing ‘n’ 
number of cycles. 
 
Fig. 9.  Maximum amplitude of the sloshing wave at various fill levels 
Fig. 10b illustrates the effect of fill level on the hydrodynamic 
damping of a sloshing wave. It is observed that damping increases 
with higher fill levels due to the increased liquid mass, which absorbs 
the kinetic energy of the sloshing waves. A regression equation is 
formulated to represent the relationship between the liquid fill level 
and changes in damping, minimizing sloshing effects.
The sloshing behaviour of fuel is analyzed by applying excitation 
motion along the transverse axis of the tank. Future work could 
extend this research by incorporating violent sloshing and combined 
excitation along both the longitudinal and transverse axes of the fuel 
tank. This regression equation can be used to predict the damping of 

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Process and Thermal Engineering
sloshing wave oscillations at fill levels within the range adopted in 
this study.
 
Fig. 10.  a) Decay of the amplitude of the sloshing wave under free vibration,  
and b) damping of the sloshing wave oscillations
4  CONCLUSIONS
This study analyzes liquid sloshing in a fuel tank at various 
oscillation frequencies and fill levels through numerical simulations 
and experimental studies using the VOF approach. The key findings 
are as follows:
The applied oscillation frequency significantly affects the 
formation of sloshing waves. At frequencies of 0.5 Hz and 0.6 Hz, 
a standing wave forms and subsequently transitions into a traveling 
wave. At 0.7 Hz, the standing wave evolves into multiple traveling 
waves, leading to wave collisions that create turbulence in the liquid 
motion.
The effect of fill levels on the amplitude of sloshing waves is 
examined with tanks filled to 25 %, 33 %, 50 %, and 60 % of their 
height. As the fill level increases, the logarithmic decrement also 
increases, causing the oscillation of the free surface wave to decay 
more rapidly.
Regression equations are developed to represent the effects of 
tank motion frequency and fill levels on sloshing wave amplitude.
This study provides valuable insights for automotive engineers to 
visualize and understand free surface wave behaviour, aiding in the 
design of fuel tanks that minimize sloshing effects. Future research 
can expand on this work by exploring violent sloshing and combined 
excitations along both the longitudinal and transverse axes of the fuel 
tank.
Nomenclature
A velocity of the tank, [m s
‒1
]
a acceleration of the tank, [m s
‒2
]
C courant number, [-]
F force exerted by the liquid on tank wall, [N]
F
r
 Froude number, [-]
f
n
 natural frequency, [Hz]
g acceleration due to gravity, [m s
‒2
]
H tank height, [m]
H
*
 non-dimensional free surface elevation, [-]
h
0
 fill level, [m]
h amplitude of free surface oscillations, [m]
l tank length, [m]
P fluid pressure, [N m
‒2
]
Re Reynolds number, [-]
T
*
 non dimensional number derived from time t [-]
t time, [s]
u velocity component along the x axis, [m s
‒1
]
V velocity of fluid, [m s
‒1
]
v velocity component along the y axis, [m s
‒1
]
X
0
  displacement of the tank, [m]
x distance from origin, [m]
∆t time step, [s]
∆x grid length, [m]
λ volume fraction, [-]
η elevation of free surface from mean liquid level, [m]
μ dynamic viscosity of the fluid, [N s m
‒2
]
ρ density of the fluid, [kg m
‒3
]
ω excitation frequency, [rad s
‒1
]
ω
n
 natural angular frequency, [rad s
‒1
]
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Acknowledgement The authors thank the management of PSG College 
of Technology, Coimbatore, TamilNadu, India, for providing the necessary 
facilities to carry out this research.
Received 2024-10-23, revised 2025-02-27, accepted 2025-03-19  
as Original Scientific Paper.
Data availability All data that support the findings of this study are included 
within the article.
Author contributions Rajamani Rajagounder: conceptualization, formal 
analysis, investigation, methodology, resources and writing – original draft; 
Jayakrishnan Nampoothiri: writing – review & editing, data curation, validation 
and visualization.
AI-Assisted writing AI-based tools were employed solely to enhance the 
readability and grammatical accuracy of the manuscript.
Vpliv vzbujalne frekvence in nivoja napolnjenosti na pljuskanje 
goriva v avtomobilskih rezervoarjih
Povzetek Študija obravnava analizo procesa pljuskanja goriva v sodobnih 
avtomobilskih rezervoarjih z namenom boljšega razumevanja delovanja 
gorivnega sistema. Obnašanje valovanja pri pljuskanju je bilo obravnavano 
pri različnih vzbujalnih frekvencah in nivojih napolnjenosti rezervoarja, in 
sicer z eksperimentalnimi ter numeričnimi metodami. Rezervoar za gorivo je 
bil vzdolž prečne osi izpostavljen sinusnemu gibanju, profili valov pa so bili 
zajeti z digitalno kamero. Numerične simulacije so bile izvedene z uporabo 
aproksimacije proste površine (metoda VOF) in uporabniško definirane 
funkcije (UDF) v programu ANSYS Fluent. Študija je pokazala različne oblike 
valovanja glede na vzbujalno frekvenco. Pri frekvencah 0,5 Hz in 0,6 Hz 
so bili opaženi stoječi in potujoči valovi, pri 0,7 Hz pa več potujočih valov z 
medsebojnimi trki. Poleg tega je povečanje nivoja napolnjenosti (z 25 % na 
60 % višine rezervoarja) bistveno izboljšalo dušenje oscilacij valov. Razvite 
so bile regresijske enačbe za kvantitativno opredelitev odnosa med vzbujalno 
frekvenco, nivojem napolnjenosti in amplitudo valov. Ti izsledki lahko 
prispevajo k načrtovanju rezervoarjev, ki zmanjšujejo učinke pljuskanja in 
izboljšajo delovanje vozila.
Ključne besede pljuskanje tekočine, rezervoar za gorivo, analiza končnih 
volumnov, vizualizacija, frekvenca valovanja