AquaBuOY scale 1:10 - Energinet.dk

Choice of Instrumentation of the 1:10 scale modelFollowing the 1:50 scale experiments in Cork, Ireland, in the spring 2007 (page 12) it was decided toincorporate a similar mechanical power take-off on the 1:10 scale model as shown oh the picture below.AquaEnergy/Finavera subcontracted the instrumentation and testing of the model to Aalborg University anda separate report describing the instrumentation is enclosed [4].The power take of based on mechanical components is shown onthe photo to the left. The PTO could be mounted on top of the float.At the top is a friction element that combined with the springsprovides the damping characteristics close to that of the hosepumps.Measurements of the piston displacement relative to the float, theload on the rod and the motion of the float.The instrumentation includesoooLoad cellPosition sensorTri-axial accelerometerBased on the force measured and the relative velocity of the piston(derived from the relative position measurements) the averagepower absorbed over a period of time can be calculated as:T1Pmech = F(t)vr( t)dtT∫0F(t)v r (t)TForce in rod connectionRelative velocity between piston and floatMeasurement periodThe measurements are stored in a data handler box on the floatpowered by batteries placed in a separate container next to thefloat.7