Innovative propulsion for large ships studies for technical development and validation around PPH concept
Laurent Barth , Henri Baerd , Lionel Julliand , Converteam SAS - Belfort , France, David Bellèvre , François Lorin , Bassin d´Essais des Carènes
After a general introduction about 10 years of back return within design, production and maintenance of MERMAID Pod type which are conventional azimuthal propulsors, the authors present now the industrial approach launched by Converteam SAS, with the technical support of hydrodynamic experts from Bassin d‘essais des carènes, in order to develop an improved concept pump-jet Pod (PPH) covering a range of power between 7 MW up to 19 MW (INOVELIS project).
This paper explains also the avantages provided by the PPH type azimuthal propulsor which concept has been previous patented by Alstom SAS (Chantiers de l’Atlantique), with regard to the performances and the compacity.
In addition, it is exposed that those excellent intrinsic propulsive performances will contribute at least to save the fuel consumption booked for the ship propulsion and to improve the comfort on board, when compared with conventional propulsor. In the same way, the INOVELIS project has retained several electro-technical solutions, in particular, the induction type engine and the MLI frequency type convertor, which are described with their own benefit.
From the hydrodynamic point of view, a technical synthesis showing the main results obtained by the Bassin d’essais des carènes to simulate the working conditions of the PPH through numerical modelling in 3D in particular under axial and manoeuvring flow conditions. Those information are considered by Converteam SAS as leader for making use of PPH, very essential input data to design the different mechanical components forming the PPH. Mechanical design is performed by DCNS, which is the partner of Converteam for the development of the complete range of PPH products.
In complement to the 3D calculations, the Bassin d’essais des carènes presents the main results obtained through experimental tests on model in cavitation tunnel (GTH and CERG) and then in towing tank which have been conducted mainly for Converteam SAS in relation ship with the shipbuilders Those experiments make possible a validation of the intrinsic performances and then the applied loads firstly estimated through the numerical approach by aid of FLUENT as Navier-Stokes modelling routine which is dedicated to simulate instationnary flows. The good reliability between the numerical and experiment results is then demonstrated.
Pilotless Aerial Vehicle Systems: Size, scale and functions
George Cho , Institute for Applied Ecology and Faculty of Applied Science, University of Canberra, Australia.
For still a lot of people, the UAV are mainly used for military purposes as reconnaissance, observation, intelligence, surveillance and also fighting and for “surgical strike”.
But in fact, there are more and more civilian uses for drones, such as surveillance (boarders, police, custom), agriculture, mapping, SAR, etc.
But, just now there is no regulation for drones building and no more for their navigation. Only some countries are working in this way. But it should be necessary to have some international principles before letting them navigate in common sky.
A super elements method developed for ship collision analysis
Nicolas Besnard , Hervé Le Sourne , Cedric Cheylan , Natacha Buannic
This paper presents a user’s friendly rapid prediction tool of damage to struck and striking vessels in a ship collision event. To do this, the so-called upper bound theorem is applied to calculate internal forces and energies of any substructure involved in the ships crushing process. At each increment of indentation, the total crushing force is transmitted to the external dynamics MCOL program, which calculates the global ship motion correction by solving the hydrodynamic force equilibrium equations.
As a first step, the paper gives a brief description of the super elements method originally developed for perpendicular collisions and recently enhanced for oblique ones. Then, the computer program SHARP which couples this method with the MCOL program developed by Principia for large rotational ship movements is presented. By comparing results obtained with and without MCOL, the importance of hydrodynamic effects is highlighted. Some simulation results are compared with results provided by classical nonlinear finite element calculations. Finally, by using the developed analytical tool which mixes internal and external dynamics, different crushing scenarios including oblique collisions are investigated and the influence of some collision parameters like longitudinal and vertical impact location, impact angle and struck ship velocity is studied.
Technology not enough to prevent accidents
Article paru dans la revue Digital Ship, novembre 2012
Modern maritime technology has the capability to vastly improve situational awareness – and yet, as numerous reports show, vessels equipped with advanced technology still manage to run into problems. examines some recent incidents where technology wasn’t enough to prevent disaster.