Numerical towing tank

Our specificity

Our numerical towing tank allows us to perform fast and reliable simulations. Thanks to the development of our OpenFOAM-based solution, it is possible for us to carry out a large number of simulations in short time and competitive costs. 

Our specificity

  • We prepare geometries for CFD analysis.

  • Our computing power (in-house cluster) with 128 cores.

  • Significant improvement in robustness and computing times under OpenFOAM by developing our own solver (marineFoam).

  • Our solver allows us to offer simulations such as self-propulsion with actuator disc (or with rotating propeller), in calm water or under waves, impossible to perform with the standard versions of OpenFOAM.

  • Mastery of the open-source semi-automated grid generator snappyHexMesh.

  • Scripts (python, Shell) to limit human intervention.

A question ? Feel free to contact us

  • You have a question on our numerical towing tank.
  • You would like to know our price and time delivery.
  • You would like to know more about our numerical methodologies and validations.
  • Or for any other question.

You can contact us by using the following link below:

Validation

Our calculation methodologies have been tested on numerous ships (container, yachts, etc.) and proven by comparing numerical results with experimental results for numerous international projects and Workshops. The examples below illustrate our in-house validation test cases.

Example 1 : full scale self-propulsion, cargo REGAL, LLOYD 2016

In 2016, LLOYD’s Register Ship Performance Group (LR) has organized the first international workshop on full scale CFD simulations. The Workshop is based, among other things, on the simulation of a self-propulsion case for REGAL cargo ship (3 speeds). The results are compared with experimental data obtained at sea during a voyage from Istanbul to Varna. Numerical simulation are performed with transient solver marineFoam and actuator disk technique. Based on known propeller revolution rate the current speed is adjusted to obtain the force equilibrium between thrust and resistance. 

overallResultComparaison
Propulsive power curve - blue (case 3.1, 71.62 rpm), green (case 3.2, 91.10 rpm), burgundy (case 3.3, 106.4 rpm), red marineFoam
histo_speed
Ship speed - case 3.1, 3.2 and 3.3
From left to righ : case 3.1, case 3.2 and case 3.3
Example 2 : Steady resistance, KRISO Container ship, Gothenburg 2010

The resistance calculations allow obtaining fundamental data on the hydrodynamic behavior of the hulls (resistance, wave pattern, wake field, pressure field, etc.) necessary for the optimization and evaluation of the performances (fuel consumption, max speed). The KCS (Kriso Container Ship) is a model ship (Lpp 7.2786 m) used in many international benchmarks (Tokyo, Gothenburg …). The example below, from the 2010 Gothenburg Workshop, consists in comparing (bare and fixed hull) the resistance and the wave pattern at Froude = 0.26 (v = 2.1964 m / s). Transient numerical calculations are carried out with marineFoam. The free surface is calculated with an implicit solver based on the modified high resolution CICSAM scheme of Wacławczyk.

wavePatternComparison
Wave pattern comparison - KCS - Fr = 0,26
Hull
Y_lpp_00741
Y_lpp_01509
coef_force
Convergence of force coefficient
Example 3 : Added resistance in waves, KRISO Container ship, Tokyo 2015

Wave/currents simulations provide data on the increase in resistance in the presence of waves (generally between 10 and 40% compared to a situation in calm sea). The example below, from the Tokyo 2015 Workshop, consists in comparing (hull with rudder) time evolution of force coefficient, heave and pitch for the KCS at Froude = 0.261 (v = 2.017 m / s), Lpp = 6.0702 m. For this case, the sea conditions are: wavelength: 11.84 m, height: 0.196 m. Numerical simulations are carried out in transient with marineFoam. The waves2foam library makes it possible to generate 5th order Stokes waves and the free surface is calculated with the modified CICSAM scheme (Wacławczyk). The boat movements (3DOF) are calculated using a predictor / corrector approach (Adams Bashforth Moulton).

ForceComparison
Force coefficient over a period
Heave
Adimensional heave over a period
Pitch
Adimensional pitch over a period
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