Scipedia

This paper aims to estimate the unknown parameters for the exponentiated Rayleigh distribution using Type-I hybrid censored data under a step-stress model. The maximum likelihood and Bayes methods estimate the parameters and acceleration factor. The parameters&rsquo; approximate confidence intervals are created. The Bayes estimates of the parameters for the squared error and linear exponential loss functions are computed using the Markov Chain Monte Carlo (MCMC) method. Finally, we perform a simulation study to evaluate the effectiveness of the proposed estimators. We provide a real-life data example (Strength data measurement in GPA, for single and impregnated carbon fibers) to explain the obtained results.OPEN ACCESS Received: 15/04/2025 Accepted: 21/08/2025 Published: 27/10/202

Fawzy, Mohamad

Alasbahi, Ibtesam

Alof, Tahani

Ahmad, Abd

Taha, Hala

El-Bary, Alaa

Lofty, Khaled

Inference of the Exponentiated Rayleigh Distribution on Step-Stress Accelerated Life Testing under Type-I Hybrid Censored Data with Physical Application

Becchi, P.

Firenze, E.

Grassi, D.

Bertetta, D.

Furcas*, F.

 
 
XI International Conference on Computational Methods in Marine Engineering 
 
 
Underwater Radiated Noise Comparison between Low and 
High Fidelity Methods 
 
Paolo Becchi1, Erica Firenze1, Davide Grassi1, Daniele Bertetta2 and Francesco Furcas1* 
 
1 CETENA S.p.A, 
Via Ippolito d’Aste, 5, 16121 Genova, Italy. 
 
2 Fincantieri Naval Vessel Business unit 
Via Cipro, 11, 16129 Genova, Italy. 
 
* Corresponding. francesco.furcas@cetena.it. 
 
ABSTRACT 
 
The capability of accurately predicting the underwater noise radiated by propellers, in the near and far field, is 
very important for both naval and civilian vessels, for different, equally relevant, reasons.  As a consequence, 
especially in the past decade, the development of methods and tools for the prediction of propeller Underwater 
Radiated Noise (URN) has been the focus of extensive academic and industrial research. 
 
From the point of view of the propeller designers, making accurate URN predictions while limiting as much 
as possible the computational effort required by the URN assessment is a key aspect, especially in the early 
design phases, when time is of the essence and a number of design alternatives need to be comparatively 
evaluated in a limited time frame. It is therefore very important to have different methods and tools available, 
of increasing degree of fidelity, and choose, for each design phase, the approach that provides the best 
compromise between accuracy and computational time. 
 
In this paper, a comparison is proposed between a Low-Fidelity method and a High-Fidelity method for the 
prediction of the noise radiated by the tip vortex of a naval propeller in conditions close to cavitation inception 
in the vortex. Cavitation inception causes a relevant increase in the URN levels, which makes the study of this 
condition particularly important in the propeller design process. 
 
The proposed Low-Fidelity methodology is based on the combination of a Boundary Element Method (BEM) 
and semi-empirical acoustic models and has been developed and validated within the Cooperative Research 
Ships (CRS), with an active involvement of the authors of this paper. The High-Fidelity methodology is based 
on using RANSE for the simulation of the near-field propeller behaviour and a combination of DES and the 
acoustic analogy (Ffowcs Williams-Hawkings) for the computation of the noise radiated in the far-field. 
Both the non-cavitating condition before inception and the cavitating condition immediately after inception 
will be analysed by comparing far field noise spectra. For the near field analysis, the noise sources will be 
assessed through comparing the pressure pulses induced by the propeller on the hull and the flow field 
fluctuations between the brackets. 
Reference  
J. Bosschers. A Semi-Empirical Method to Predict Broadband Hull Pressure Fluctuations and Underwater 
Radiated Noise by Cavitating Tip Vortices. Fifth International Symposium on Marine Propulsors smp’17, 
Espoo, Finland, June 2017 
 2
E. Firenze, F. Valdenazzi. A method to predict underwater noise from cavitating propellers. OCEANS 2015, 
Genova, 18-21 May 2015 
S. Iannello, C. Testa. An Overview on the use of the FFowcs Williams-Hawkings equation for the 
hydroacoustic analysis of marine propellers. VIII International Conference on Computational Methods in 
Marine Engineering, MARINE 2019 
M. Ge, U. Svennberg, R. E. Bensow. Investigations on prediction of ship noise using the FWH acoustic analogy 
with incompressible flow input. Ocean Engineering 257 (2022) 111531 
J. Baltazar, B. Schuiling, D Rijpkema. Propeller Performance Prediction in an Artificially Generated Wake 
Field Using RANSE. 22nd Numerical Towing Tank Symposium, Tomar, Portugal, 2019. 
 
 


Underwater Radiated Noise Comparison between Low and High Fidelity Methods

Nagano*, Y.

Ojeda, G.

Lara, J.

 
 
XI International Conference on Computational Methods in Marine Engineering 
 
OpenFOAM-based hybrid CPU/GPU coupled solver on Navier-Stokes equations 
and shallow water equations 
 
Yuichi Nagano1,*, Gabriel Barajas Ojeda2 and Javier L. Lara2 
 
1 Taisei Advanced Center of Technology, Taisei Corporation 
344-1, Nase-cho, Totsuka-ku, Yokohama, Kanagawa, Japan. 
 
2 IHCantabria, University of Cantabria 
C/ Isabel Torres 15, PCTCAN, Santander, Cantabria, Spain. 
 
* ngnyui00@pub.taisei.co.jp 
 
ABSTRACT 
The aim of this work is to create a fast, robust, accurate and reliable numerical wave tank (NWT) that can 
simulate the hydrodynamics that take place in the swash zone. 
Mintgen and Manhart (2018) created a coupled solver for the Navier-Stokes (NS) equations and the Shallow 
Water (SW) equations in the OpenFOAM framework designed for river flooding and urban inundation. Its 
applicability to marine areas was not verified. In addition, the solver could only be run in CPUs.  
In this study, a novel hybrid CPU/GPU coupled solver has been developed by merging interFoam, a standard 
NS solver in OpenFOAM, with a SW solver written using CUDA and running on GPUs. By coupling both 
numerical approaches, the computational costs are reduced, allowing to increase the zones of interest. 
Validation of the new solver has been done following O'Donoghue et al. (2010), reproducing the detailed 
measurements of hydrodynamics with swash generated by bore collapse on a steep beach (Fig. 1). Free surface 
evolution was analysed by comparing numerical results to measured water depth (Fig. 2). 
References 
F. Mintgen and M. Manhart. A bi-directional coupling of 2D shallow water and 3D Reynolds-averaged Navier–
Stokes models. Journal of Hydraulic Research, 56(6), 771-785, 2018. 
T. O'Donoghue, D. Pokrajac and L. J. Hondebrink. Laboratory and numerical study of dambreak-generated 
swash on impermeable slopes. Coastal Engineering, 57, 513–530, 2010. 
0.65 m
3.8 m1.0 m 8.0 m
A B
NS domain SW domain
Figure 1: Experimental setup (O'Donoghue et al. (2010)) 
Figure 2: Comparison between the numerical results and the measured water depth 


OpenFOAM-based hybrid CPU/GPU coupled solver on Navier-Stokes equations and shallow water equations

Lasbleis*, M.

Akkari, S.

Tierno, M.

Descamps, T.

Ducrozet, G

Bouscasse, B.

 
 
XI International Conference on Computational Methods in Marine Engineering 
 
 
Numerical Wave Generation and Propagation with High Order Spectral Method 
in OpenFOAM 
 
Marine Lasbleis1,*, Sabrine Akkari2, Matthieu Tierno2, Théo Descamps3, Guillaume Ducrozet2 and 
Benjamin Bouscasse2 
1 Bureau Veritas Marine & Offshore, Research Department, Saint-Herblain, France 
2 Nantes Université, Ecole Centrale Nantes, CNRS, LHEEA, UMR 6598, Nantes, France 
3 Bureau Veritas Solutions Marine &Offshore, Saint-Herblain, France 
* marine.lasbleis@bureauveritas.com 
 
ABSTRACT 
In naval and offshore applications, waves are a key component. 
The ships and offshore structures operate in various sea states, 
from mild to extreme conditions. When modelling the wave-
structure applications in a numerical set-up, various types of 
waves and waves generation are considered: regular or 
irregular waves, long crested or short crested waves, infinite 
ocean or closed experimental tanks with wave makers, etc. 
Some of these conditions are far from the real conditions 
encountered by a ship but are used to build extensive datasets 
to extrapolate over the life span of the structures. To be useful, 
a numerical wave tank should be able to reproduce these 
different waves and wave conditions easily. This includes for 
example: the reproduction of regular and irregular waves 
exactly as run in a known experimental set-up, including 
the initial ramp of the waves; the focalisation of a focus 
wave at a target time and position; short-crested and long-
crested irregular sea state.  
In this paper, we present the results of our numerical wave tank to generate efficiently and precisely these 
different wave and wave-structure cases. We use an in-house viscous flow solver, foamStar, based on the open-
source library OpenFOAM.  The wave generation is managed through explicit forcing/relaxing-zones method 
inspired by the library wave2Foam (Jacobsen et al. 2012). Within this technique, it is necessary to have a 
volumetric solution of the wave field at each time step. Several wave models have been implemented and the 
focus of this paper is the use of High Order Spectral method (Ducrozet et al. 2012) which provides a nonlinear 
potential flow solution, through the HOS software developed by the Ecole Centrale de Nantes and the 
Grid2Grid library developed to reconstruct the volumetric solution (Choi et al. 2023). 
References 
Jacobsen, N. G., Fuhrman, D. R., & Fredsøe, J. (2012). A wave generation toolbox for the open‐source CFD 
library: OpenFoam®. International Journal for numerical methods in fluids, 70(9), 1073-1088.  
Ducrozet, G., Bonnefoy, F., Le Touzé, D., & Ferrant, P. (2012). A modified high-order spectral method for 
wavemaker modeling in a numerical wave tank. European Journal of Mechanics-B/Fluids, 34, 19-34.  
Choi, Y. M., Bouscasse, B., Ducrozet, G., Seng, S., Ferrant, P., Kim, E. S., & Kim, Y. J. (2023). An efficient 
methodology for the simulation of nonlinear irregular waves in computational fluid dynamics solvers based 
on the high order spectral method with an application with OpenFOAM. International Journal of Naval 
Architecture and Ocean Engineering, 15, 100510. 
Figure 1: Reproduction of a regular waves with initial ramp 
measured in and experimental wave tank, CFD run with 
coarse Mesh lambda/DeltaX = 39 and H/Delta Z = 4 


Numerical Wave Generation and Propagation with High Order Spectral Method in OpenFOAM

Wang*, J.

Zhang, W.

Wan, D.

 
 
XI International Conference on Computational Methods in Marine Engineering 
 
 
Ship hydroelastic responses and slamming loads of an ultra-large containership 
in different conditions 
 
Jianhua Wang, Wenjie Zhang and Decheng Wan* 
 
Computational Marine Hydrodynamics Lab (CMHL), School of Ocean and Civil Engineering, 
Shanghai Jiao Tong University, Shanghai 200240, China 
 
* Corresponding author dcwan@sjtu.edu.cn 
 
ABSTRACT 
An accurate prediction of ship motions, slamming 
loads and structural responses has long been an 
important research interest in the field of ship 
hydrodynamics. With the tendency of modern ships 
towards large-scale and light-weighted, the 
significance of hydroelastic responses in ship 
hydrodynamic analysis has escalated, especially for the 
ships with large lengths. Ships are becoming more 
flexible, and the hull structural deformations can 
significantly affect the flow field and wave loads. In 
this situation, fully coupled Flexible Fluid Structure 
Interaction (FFSI) approach is needed in the numerical 
simulations of ship hydroelasticity analysis. 
In this paper, a two-way coupled CFD-MBD solver (Zhang et al., 2025) is applied to study the seakeeping 
performance and hydroelastic responses of a 20,000 TEU containership. The flow field is solved by RANS 
(Reynolds Averaged Navier-Stokes) equations with OpenFOAM, an open source CFD software. The structural 
deformation of hull girder is solved by MBDyn with multi-body dynamic method. The data transformation of 
fluid pressure and structural deformation in the FSI procedure is realized with the help of preCICE, an open 
source library for FSI communication (Xiao et al., 2024). The flow field mesh is updated by solving a 
Laplacian’s equation. Numerical predictions of ship motions and vertical bending moment (VBM) responses 
are validated against experimental measurements in regular head waves with varying wavelengths and ship 
speeds. The effects of wave height and ship speed on hydroelastic responses and slamming loads are 
systematically analyzed. The results show that VBM and slamming loads can increase significantly with 
changes in wave parameters, with more intense nonlinear effects observed under higher wave height conditions. 
In higher-speed cases, the peak value of VBM shifts from the midship to the bow region. These findings 
provide valuable data for the evaluation of ship hydroelasticity in ocean waves, particularly for ultra-large 
containerships. 
References 
J. Xiao, C. Liu, B. Han, D. Wan and J. Wang, A two-way coupled fluid–structure interaction method for 
predicting the slamming loads and structural responses on a stiffened wedge, Physics of Fluids, 2024, 36, 
077123. 
W. Zhang, J. Wang, H. Guo, Y. Liu and D. Wan, Numerical investigations of ship hydroelasticity of a 20,000 
TEU containership based on CFD-MBD method, Ocean Engineering, 2025, 317: 120061. 
 
Figure 1: Comparison of vertical bending 
moment in different wave heights. 
 


Ship hydroelastic responses and slamming loads of an ultra-large containership in different conditions

Abgrall*, M.

Perali, P.

Sacher, M.

Clément, B.

Leroux, J.

Gokp, K.

XI International Conference on Computational Methods in Marine Engineering
Experimental and numerical study of an oscillating foil near the free surface
M. Abgrall1,2,∗, P. Perali1, M. Sacher1, B. Clément1, JB. Leroux1, K. Gokpi2, R. Lécuyer-Le-Bris2,
M. Le Boulluec3
1 IRDL, ENSTA Bretagne, CNRS UMR 6027, 2 rue François Verny, 29200, Brest, France
2 BLUEFINS, 130 Cours Aimé Césaire, 29200, Brest, France
3 IFREMER, 1625 Rte de Sainte-Anne, 29280, Plouzané, France
∗ matthieu.abgrall@ensta-bretagne.org
ABSTRACT
Previous studies have explored hydrofoils as a means
to enhance ship propulsion in waves, focusing on
both passive and active motion control (X. Wu et al.,
2020). However, some aspects as free-surface effects
on thrust performance remains less understood for 3D
configurations, including with regular waves at the
surface (J. Deng et al., 2022 ; N. Petikidis et al. 2023).
This work presents experimental and numerical re-
sults to study the performances of an actively pitch-
ing and heaving NACA0015 near the free surface.
The experiments are carried out in the Ifremer current
and wave tank at Boulogne sur Mer for several heave
and pitch amplitudes. The influence of the phase lag
between the pitch and heave motions is also investi-
gated, as well as the hydrofoil performances in regular
waves. The experiments consists of forces measure-
ments and there are compared with numerical predic-
tions of the hydrodynamic forces using the potential
flow code PUFFIn in its latest unsteady version, based
Figure 1: Temporal comparisons of experimentally and
numerically generated forces by an oscillating foil in
heave and pitch near the free surface.
on the boundary element method (P. Perali et al.,
2024). Overall, the mean numerical forces exhibit
similar trends to the experimental averages, validat-
ing the use of the potential flow code to optimize foil
kinematics or geometry.
References
X. Wu, X. Zhang, X. Tian, X. Li, and W. Lu, A review
on fluid dynamics of flapping foils, Ocean Engineer-
ing, vol. 195, 2020.
J. Deng, S. Wang, P. Kandel, and L. Teng, Effects of
free surface on a flapping-foil based ocean current en-
ergy extractor, Renewable. Energy, vol. 181, 2022.
N. Petikidis et G. Papadakis, Investigation of Submer-
gence Depth and Wave-Induced Effects on the Perfor-
mance of a Fully Passive Energy Harvesting Flapping
Foil Operating Beneath the Free Surface, Journal of
Marine Science and Engineering, vol. 11, 2023
Figure 2: NACA0015 hydrofoil employed for
experimental testing in the Boulogne-sur-Mer towing tank.
P. Perali, M. Sacher, JB. Leroux, J. Wackers, B.
Augier, F. Hauville and P. Bot, Performance predic-
tion of a hydrofoil near the free surface using low
(BEM) and high (RANS) fidelity methods, Applied
Ocean Research, vol. 151, 2024.


Experimental and Numerical Study of an Oscillating Foil Near the Free Surface

Roche*, H.

Kerdraon, P.

NACRA17 real time dynamic simulation 
 
Hugo Roche*, Paul Kerdraon† 
* VPLP 
18 Allée Loïc Caradec, 56000 Vannes, France 
e-mail: h.roche@vplp.fr, web page: https://vplp.fr/ 
  
† VPLP 
18 Allée Loïc Caradec, 56000 Vannes, France 
e-mail: p.kerdraon@vplp.fr, web page: https://vplp.fr/ 
 
 
 
 
ABSTRACT 
 
 
 
This study presents the development and validation of physical models to simulate the behavior of the 
NACRA17 Olympic catamaran in a real-time dynamic environment. Simulations are carried out 
within an in-house system-based dynamic velocity prediction program (DVPP) [1]. Key components 
include the hydrodynamic and structural response of the appendages for fluid-structure interaction 
(FSI), the hydrodynamic modeling of the hulls and the aerodynamic modeling of the rig. A significant 
aspect of the study involved designing control laws to replicate crew movements, enabling active 
control for flight stability during simulation. Validation was performed through two complementary 
approaches: measuring the static structural response of the appendages on a jig and assessing the 
overall performance of the catamaran during sailing trials. These validated models, combined with 
active control strategies, provide a robust framework for analyzing the catamaran's performance and 
behavior under realistic conditions, offering valuable insights for athletes training and performance 
enhancement, with optimization of boat trims and control strategies. 
 
 
 
 
 
 
REFERENCES 
[1] Kerdraon, P. et al. Development of a 6-DOF Dynamic Velocity Prediction Program for offshore 
racing yachts. Ocean Engineering 212 (2020). 
[2] Graf, K., et al. VPP-Driven Sail and Foil Trim Optimization for the Olympic NACRA 17 Foiling 
Catamaran. Journal of Sailing Technology 5 (2021) 
[3] Knudsen, S. et al. Towards Dynamic Velocity Prediction of NACRA 17. Journal of Sailing 
Technology 8 (2023) 


NACRA17 real time dynamic simulation

Preuveneers*, J.

Smyth, A.

Mare, L.

XI International Conference on Computational Methods in Marine Engineering
High Efficiency Swimming using Hydrodynamic Eigenmode Decomposition
Jack Preuveneers1,∗, Amanda Smyth2 and Luca Di Mare1
1 Oxford Thermofluids Institute, Department of Engineering Science,
University of Oxford, Osney Mead, Oxford OX2 0ES
2 Oxford Environmental Fluid Mechanics Group, Department of Engineering Science,
University of Oxford, Parks Road, Oxford OX1 3PJ
∗ jack.preuveneers@eng.ox.ac.uk
ABSTRACT
Underwater swimming can exhibit remarkable effi-
ciency, as evidenced by adept aquatic animals. This
study introduces a novel approach for systematically
uncovering high-efficiency motion patterns in flexi-
ble three-dimensional rectangular bodies via hydrody-
namic eigenmode decomposition.
By formulating and solving a generalised eigenvalue
problem from the governing hydrodynamic equations,
we show that the resulting complex eigenvalues clus-
ter into distinct families defined by chordwise and
spanwise wavenumbers. The chordwise wave mani-
fests as a travelling wave, whereas the spanwise is a
standing wave. The imaginary and real components
of these hydrodynamic eigenmodes respectively cap-
ture the oscillatory and growth/decay characteristics
of the flow, enabling us to pinpoint modes that gener-
ate thrust with minimal input.
We further examine how varying the plate’s aspect
ratio significantly affects the clustering and spacing
of these eigenvalue families. oderate combinations
of chordwise and spanwise wavenumbers yield espe-
cially high propulsive efficiency. Moderate combina-
tions of chordwise and spanwise wavenumbers yield
especially high propulsive efficiency, while higher
chordwise wave numbers correspond to shorter wave-
lengths and larger imaginary eigenvalues. An inverse
relationship also emerges between reduced frequency
and spatial growth rate. These findings underscore
a direct link between eigenvalue characteristics and
optimal kinematic strategies. By bridging the gap
between hydrodynamic theory and biologically in-
formed design, this hydrodynamic eigenmode based
framework offers a powerful route for selecting and
tuning modes in biomimetic or engineered systems.
By focusing solely on the hydrodynamic response -
without introducing structural complexities - this ap-
proach provides a promising route toward advanced,
energy efficient designs for autonomous underwater
vehicles and marine robotics.
Figure 1: Example of an eigenvector motion patterns, representing variations in aspect ratio


High Efficiency Swimming using Hydrodynamic Eigenmode Decomposition

Cook*, J.

Banks, J.

Experimental investigation of IQFoil Lift and Drag in a towing tank 
Jamie Cook1, Joseph Banks1,  
1 Maritime Engineering Research Group, School of Engineering, University of Southampton, UK 
Abstract: 
There has been limited towing tank testing for sailing hydrofoils producing both large forces and 
moments due to the challenges this presents to dynamometry.  
In this paper, a windsurfing iQFOiL was tested in a towing tank using a new experimental rig to measure 
both lift and drag forces. Numerical predictions of the foil forces were created using XFLR5 to provide 
design loads for the dynamometry. The hydrofoil was tested up to speeds of 8 m/s and over a range of 
pitch angles, which affect the foil's angle of attack. Repeat tests were conducted and the measurement 
uncertainty was calculated to assess the reliability of the developed dynamometry and test methods, 
as presented in Figure 1. The impact of pitch angle and rear foil angle on the forces generated are 
presented and discussed.  
It was found the equipment was capable of repeat readings within 0.5% when operating at realistic 
foiling speeds and could measure lift forces up to 1200 N. Furthermore, the equipment had an average 
uncertainty of 6.43 newtons and 2.19 newtons for lift and drag measurements respectively. 
The interaction effects between the lift and drag forces measurements were assessed after the 
experiment and were shown to vary by up to 3.6%. Recommendations to improve the measurement 
accuracy are discussed and the suitability of the experiments for validation of numerical simulations 
are explored. 
 
 
Figure 1-Measured lift and drag for increasing speed with a repeat reading (Pitch = 0◦, Rear wing chock = 1◦) 
 
 
 
 


Experimental investigation of IQFoil Lift and Drag in a towing tank

Bot*, P.

François, P.

Hauville, F.

Soton, S.

Astolfi, J.

 
 
XI International Conference on Computational Methods in Marine Engineering 
 
 
Experimental Investigation of two Typical Hydrofoil Sections with Cavitation 
 
P. Bot1,*, P. François1, F. Hauville1, J.A. Astolfi1, S. Soton2  
 
1 Arts et Métiers Institute of Technology, IRENav, CC600 29240 BREST Cedex 9, France. 
2 SEAir Solutions, 10, rue Chalutier les 2 Anges, 56100 Lorient, France  
 
* Corresponding Author: patrick.bot@ecole-navale.fr 
 
 
ABSTRACT 
Hydrofoils are now largely used on high-speed sailing boats and leisure crafts, and their hydrodynamic 
behaviour is critical for the performance of the vessel. Cavitation is often a major constraint on these highly 
loaded lifting structures as it is generally considered to have a negative impact on performance. In foil design, 
a first common approach is to impose a non-cavitation constraint in the optimisation process (e.g. Galen et al. 
2025), and the foil sections are adjusted to delay cavitation inception to the highest possible speed. However, 
at sailing speeds in the 40-50 knots, cavitation cannot be avoided, and the design should be able to consider 
the effect of a more or less developed cavitation on the hydrodynamic performance. Numerical simulation can 
predict the threshold of cavitation inception reasonably well when the minimum pressure in the non-cavitating 
flow reaches the vapor pressure (𝐶𝑝𝑚𝑖𝑛 = −𝜎), but predicting the hydrodynamic forces in the cavitating 
regime is a challenge and the existing cavitation models still need validation. At the highest speeds, 
supercavitating sections -not studied here- are preferred to promote cavitation and avoid instability due to 
strongly fluctuating vapor cavities (e.g. Vernengo et al. 2016). This work presents an experimental 
investigation in the IRENav cavitation tunnel of two foil sections typical of take-off and high-speed sailing 
operating points, corresponding to a two-element foil (main and flap) with two different flap deflection angles. 
Hydrodynamic forces are measured in the subcavitating regime, at the onset of cavitation and in developed 
cavitation. The cavitating flow is visualized with high-speed cameras. The velocity field is measured in the 
non-cavitating regime with time-resolved Particle Image Velocimetry. When cavitation sets in, a slight increase 
in lift coefficient is measured before a drop into well-developed cavitation. However, the drag coefficient 
increases too, gently as soon as cavitation appears, then strongly when the cavitation number decreases, up to 
double in developed cavitation. Thus, the lift to drag ratio only decreases under the effect of cavitation. 
 
   
 
 
 
 
Figure 1: Cavitation Maps and typical cavitation patterns on both foil sections 
References 
Galen W. Ng, Yingqian Liao, Anil Yildirim, Joaquim R.R.A. Martins, Hydrostructural optimization of 
subcavitating cambered and symmetric composite foils, Composite Structures, Volume 351, 2025 
Vernengo G., Bonfiglio L., Gaggero S. and Brizzolara S., Physics-Based Design by Optimization of 
Unconventional Supercavitating Hydrofoils, J. Ship Research 60, 4, 187-202, 2016 


Experimental Investigation of two Typical Hydrofoil Sections with Cavitation

Not a member yet