On the arrangement of two experimental activities on a novel multi-purpose floating structure concept

Abstract

The Blue Growth Farm" is an ongoing H2020 European project, aimed to the development, engineering and demonstration of a new floating multi-purpose platform concept, devoted to aquaculture, and wind-wave energy production. Due to the significant complexity of the coupled dynamic behavior of the proposed concept, model tests are essential to investigate the most relevant physical phenomena and validate/calibrate the pertinent numerical models. However, the realization of a scaled model of such structure is by itself quite challenging, since each sub-system follows its own scaling laws and requires different strategies to minimize scale effects. The aim of the present paper is to describe the arrangement of the experimental activities, discussing the mechanisms of the scale factor at different scales and related results accuracy, scaling strategies and test environments. The two-phase framework and the scaling strategies proposed may be also useful for future activities on similar concepts.

Scaling strategies for multi-purpose floating structures physical modeling: state of art and new perspectives

“…The following ideal classification could be proposed for outdoor activities: 1) prototypal campaigns on close-to-full-scale floating platforms (see e.g. [47,48]); 2) intermediate-scale experiments performed at sea [15,27]. Actually, the distinction between these two classes is rather arbitrary (see e.g.…”

“…In the last years, a growing interest for these activities has been recorded from research centers and offshore companies, as the growth in size and complexity of the proposed floating structure concepts, especially in the case of MPPs, requires further intermediate steps between small-scale indoor experiments (TRL 3-5) and prototypal activities. Based on these considerations, a detailed comparison between traditional indoor experiments and intermediatescale outdoor activities is here presented, to support decision-making in the planning of the experiments (see also [15] for a practical application on a MPP concept)…”

“…If so, d w should be chosen in a way that the two Re ranges correspond to c d and cl coefficients as close as possible between each other. An example of dw optimization, based on the proposed criterion, can be found in [15], where the arrangement of two 1:40 (indoor) and 1:15 (at-sea) experimental campaign on a MPP were described. In such case, the increase of the model scale from indoor to outdoor testing was crucial to minimize the drag coefficient alteration.…”

A large-scale wind turbine model installed on a floating structure: experimental validation of the numerical design

“…During the aforementioned project, actually, two test campaigns were performed to investigate the behaviour of the platform and get hints on its feasibility. The first campaign was about a 1:40 model tested in a wave tank, at ECN; the second campaign, explained in this paper, was conducted on a 1:15 40 model, then a large-scale model, to inspect the behaviour of the platform in open sea (Ruzzo, et al, 2021). Largescale models deployed in a natural outdoor environment are a valid complement to traditional small-scale laboratory models in understanding the real features of the system and in updating or validating codes.…”

Aerodynamic and Structural Strategies for the Rotor Design of a Wind Turbine Scaled Model

“…For the first kind of tests, the typical scale allowed is between 1:50-1:100 for wave basin tests and 1:75-1:200 for wind tunnel tests, while higher scales can be adopted for outdoor models. In particular, in the latter case, we can distinguish between prototypal campaigns on close to full-scale wind turbines (see, e.g., [14,15]) and intermediate-scale experiments performed at sea [16,17]. Prototypal activities are generally characterized by a scale lower than 1:10 and a TRL (Technology Readiness Level) of about 7-9 and are generally performed just before commercial development, while intermediate-scale tests are more research-oriented tests, with a TRL of about 5-7 and length scale between 1:10 and 1:20.…”