Maritime – Various

Buoy DynamicsThales Nederland is the Dutch branch of the international Thales Group. The company has about 2,000 employees working at branches in Hengelo (HQ), Huizen, Houten, Delft, Enschede

and Eindhoven. Thales Nederland specializes in designing and producing professional

electronics for defense and security applications, such as radar, command and control, and

communication systems. For one of its projects, Thales wanted to investigate the dynamic behavior of sea buoys with respect to external forces, like wind, waves and currents, and also

the infuence of different configuration of the buoy like size, mass, and length. Thales consulted Controllab to create a sea buoy model and carry out simulations to investigate the

effects of wind, waves and currents.

Seriously Improving Control

photo: courtesy of changeable focus, Flickr

CompanyThales Nederland is the Dutch branch of theinternational Thales Group. The company hasabout 2,000 employees working at branchesin Hengelo (HQ), Huizen, Houten, Delft,Enschede and Eindhoven. Thales Nederlandspecializes in designing and producingprofessional electronics for defense andsecurity applications, such as radar, commandand control, and communication systems. Forone of its projects, Thales wanted toinvestigate the dynamic behavior of seabuoys with respect to external forces, likewind, waves and currents, and also theinfuence of different configuration of thebuoy like size, mass, and length. Thalesconsulted Controllab to create a sea buoymodel and carry out simulations toinvestigate the effects of wind, waves andcurrents.

ProjectWaves can be described by orbital paths ofwater particles. The radius of this orbital pathis equal to the wave amplitude at the surfaceand decreases to zero at a depth of half thewave length. A model has been made in 20-sim that describes the motion of the waveparticles as a function of the wave heightand length. The points are defined as a

moving grid which can be used to calculatethe relative velocity of any foating objectwith respect to the water. Any object foatingin the water will experience forces becauseof buoyancy, wind drag, water drag andadded mass. All of these effects were addedto the model which was created in the 3D-Mechanics editor.

Simulations were carried out to investigatevarious buoys configurations under theinfuences of wind, wave height and wavelength and current. The figure below showsone of those simulations where the buoystarted surfing on the wave tops and movingwith the wave direction very quickly.

ControllabControllab is active in the Marine andOffshore market for more than 20 years. Ourengineers have gained a thoroughunderstanding of servo hydraulics, electricdrives and machine design. They were able toshare this knowledge with SMST and helpSMST to become one of the leadingcompanies in motion compensated accessbridges.

Contact

Christian KleijnManaging director +31 (0)85 773 1872

__________________________________________________________________________________________________© Controllab Products, Hengelosestraat 500 , 7521 AN Enschede, the Netherlands, www.controllab.nl , Chamber of Commerce: 06076204

Motion of Wave particles.

Simulated buoy surfing on the waves.