Risers Model Tests: Scaling Methodology and Dynamic Similarity

摘要

This works addresses the problem of how to scale catenary riser modelrntests, properly considering dynamic similarity. A review on the mostrnimportant dynamic characteristics and parameters is presented and arnrelevant group of representative nondimensional numbers is analyzed.rnNot only FPU induced global dynamics is taken into account as well asrnVIV and other important phenomena of localized nature, such as thosernthat are typical of the touch-down zone. The general rationale is basedrnon analytical and asymptotic dynamic solutions, previously constructedrnby means of standard perturbation techniques and asymptotic methods.rnSuch a rationale gave rise to a new concept for small scale riser modelrndesign and construction. A riser model made of a silicone tube filledrnwith stainless steel microspheres showed to best fit the intendedrndynamic similarity, focusing on experiments in two distinctrnlaboratories: a wave ocean basin and a towing tank. A series ofrnexperimental tests, specially designed to assess the main dynamicrncharacteristics and structural parameters of the riser model, was carriedrnout. The experimental methodology and a summary of results arernshown. Finally, a critical analysis, comparing static and dynamicrnnumerical simulations, both in full and model scales, is also presented.