The 12th International Conference on Hydrodynamics
18 – 23 september 2016, Egmond aan Zee, The Netherlands
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NUMERICAL SIMULATIONS OF HYDRODYNAMIC TESTS FOR UNDERWATER VEHICLES


Go-down ichd2016 Tracking Number 6

Presentation:
Session: Computational Fluid Dynamics III
Room: Room 2
Session start: 15:30 Mon 19 Sep 2016

Sertaç ARSLAN   sarslan@roketsan.com.tr
Affifliation: Roketsan A.Ş.

Emrah GÜLAY   egulay@roketsan.com.tr
Affifliation: Roketsan A.Ş.

Mete INEKÇI   egulay@roketsan.com.tr
Affifliation: Roketsan A.Ş.


Topics: - Hydrodynamics in ocean, coastal and estuary engineering, - Computational fluid dynamics

Abstract:

Hydrodynamic coefficients must be obtained to examine controllability and maneuverability characteristics of an Autonomous Underwater Vehicle (AUV). Experimental, numerical and empirical methods are different ways to predict hydrodynamic coefficients. Various captive tests, such as; straight-line towing, Rotating Arm (RA), Planar Motion Mechanism (PMM), and Coning Motion Mechanism (CMM) tests can be conducted to obtain hydrodynamic coefficients or maneuvering derivatives that are necessary for system simulation of AUVs. Although the most reliable way to determine hydrodynamic coefficients of an AUV is conducting hydrodynamic tests, thanks to developments in computer technology it is possible to solve flow problems by using Computational Fluid Dynamics (CFD) methods. In this study, CFD modelling techniques are developed to simulate straight-line towing tests, RA tests and PMM tests. These test scenarios are modeled by using CFD methods. FLUENT commercial flow solver is used to solve these flow problems. Firstly, Defense Advanced Research Projects Agency (DARPA) and UK Natural Environment Research Council’s Autosub test-case models are used for straight-line towing test simulations. Then RA and PMM tests are simulated for only Autosub test-case model. Rotating arm tests are simulated for constant angular velocity and constant angular acceleration. Furthermore, pure heave motion is simulated in the scope of PMM studies. FLUENT user defined functions are used for the analyses that mesh motions are needed. Analyses results are compared with experimental data which is available in literature. Finally, hydrodynamic database of Autosub model, which is produced by CFD methods, used for stability and performance analyses to determine maneuverability characteristics of Autosub model.