SCALING RATIO EFFECTS ON THE PREDICTION OF DYNAMIC MOTION ANALYSIS OF OFFSHORE FLOATING WIND TURBINES

ABSTRACT

In this study, three scaling ratio size of 5MW NREL Spar-type Floating Offshore Wind Turbine will be used to analyse the dynamic analysis according to the six degrees of freedom. From the results that have been studied in the past papers, they have been identified the six degrees of freedom of the spar-type floating offshore wind turbine (FOWT). From that, we will use the scaling Froude Scaling Ratio to scaling down the size of the FOWT and do the simulation based on three scaling rations that have been classified. After that, the results of six degrees of freedom of the simulation will be compared to the actual results from the past papers. Based on the results interpretation and discussion, we will get the effect of the scaling ratio that we used in order to identify the dynamic motion of FOWT.

The use of Froude Scaling Law because of the size of the actual FOWT is very big and there is no wave tank that can fit the size. So, we need to scale down the size in order to do the testing. Spar-type will be using the scale of 1:50, 1:100 and 1:250. The difference of the scaling ratio is going to effect the results of the dynamic analysis from the simulation. The results of the simulation will be scaling up using scaling law and to be compared with the reference results of past paper.

To design the spar-type FOWT, Catia software is used in designing all the part of FOWT including the wind turbine properties, platform properties and also the mooring system properties. The model will be designed in very detail including all the blade, nacelle, bearing, shaft and bolt. After that, all the part will be ensemble together in order to do the simulation with STAR CCM+ software.