The National Research Council of Canada is presently constructing and preparing to commission a 75 m x 32 m x 3.5 m Offshore Engineering and Seakeeping Basin at the Institute for Marine Dynamics in St. John's, Newfoundland. The Basin will be capable of simulating waves, wind and current, for use in both commercial and research programs. The first stage of commissioning and calibration will focus on preparing the Basin, scheduled for completion in February 1990, for commercial testing of moored and free running vessels.
Waves are gene rated in the Basin by means of a 192 segment wave machine, mounted in a "J" configuration. Short and long-crested monochromatic and random waves will be generated using the snake principle. Passive wave absorption is utilized in the Basin using expanded metal sheets of varying porosities and spacings. These are located at all Basin wall locations not supporting wave generators.
A bank of 24 analog controlled fans is used to generate wind. Turbulence spectra and velocity profiling are established by fluctuating the speed of the fans using precalibrated drive signals. Surface current is generated by setting up water circulation within the Basin. Submersible pumps are used to charge manifolds positioned at various levels below the surface.
The data acquisition system, controlled by a microVAX-II computer, is capable of variable rate sampling of 128 channels of A/0 and can simultaneously output 16 channels of DIA. The microVAX is networked to a local VAX 3200 used for synthesis of drive signals and test data reduction and analysis. Model motions in six degrees-of-freedom are measured using an optical tracking system, consisting of three vertical and two horizontal cameras, and light emitting diodes positioned on the model.
