Hydrodynamic and Ocean Engineering Tank

Presentation

It is 50 m long, 30 m wide and 5 m deep. The Hydrodynamic and Oceanic Engineering tank of Centrale Nantes is equipped with a segmented wave beater composed of 48 independent flaps to generate directional swells. A wind generation system producing an air flow with a section of 3m by 3m with speeds up to 15 m/s can be placed above the tank.

This tank allows the physical simulation on a reduced scale of floating systems, sailing or mooring in the open sea (ships, MRE systems or oil platforms).

Due to its size and its generation capacities, it is currently the largest tank in France dedicated to this type of study.

 

Main features

Dimensions:

50m x 30m x 5m with a central openable shaft (5m x 5m x 10m)

Preparation area:

A large 15 x 15m preparation area is dedicated to the assembly and the preparation of the tests.

Footbridges:

The tank is equipped with three movable transverse footbridges:

• A small one (30mx0.5×0.5) for instrumentation only
• An medium one (30mx2x1.5) for access to the measurement area and instrumentation
• A larger and taller one (30mx3x3) for supporting heavy parts of the experimental setups above water 

Overhead crane:

The overhead crane covers the entire BHGO area, as well as the preparation area. It has two hoists and has a maximum capacity of 4 tons. The hoists can operate independently or synchronously. The maximum clearance from the ground is 8.50m.

Qualified divers:

A team of two qualified IB category divers is available to operate in the BHGO.

Waves:

The tank is equipped with a segmented wave maker, composed of 48 hinged flaps distributed over the width of the basin. Each flap is controlled in position separately. The wave generator system is equipped with an active wave absorption (force) control feature.

The other end of the basin is composed of a 7m passive wave breaking beach (gentle slope and quadratic profile).

The wavemaker control software, used together with enhanced control laws from the literature and implemented at LHEEA (Dalrymple method, Molin method (disc or rectangle)), gives access to the following high quality waves :

• Regular and irregular waves
• Unidirectional / directional waves
• Irregular crossing waves (angle up to 90°)

Wave parameter range:

• Periods T 0.5 to 5.0 s
• Regular wave height H max 1.0 m
• Irregular wave height Hs max 0.6 m

Wind:

Description to come
 

Instrumentation

• QUALISYS trajectory motion capture system (Aerial and submarine)
• Resistive, capacitive and ultrasonic wave sensors
• Tripod for maintaining tructures or setups above water
• Self-propelled models
• Synchronized HD video system (Air and Underwater)
• Acquisition and analysis systems (Matlab, LabVIEW, RTMaps