Computational fluid dynamics (CFD) is best described as a fluid flow predictive modeling application. This methodology, which is used to study the flow of liquids, began to gain credibility and acceptance in the 1970s. Since those early days, CFD has grown exponentially in accuracy and evaluations as it relates to the flow of water over the hull, appendages (such as stabilizers), roll damping, and overall drag, proving to be a tremendous value to the vessel owner, crew, designers, and engineers.
An in-depth CFD study will consider the roll period, metacentric height (GM), displacement, beam, and sea state requirements. These inputs help to anticipate performance at varying speeds and sea conditions, better understand the effectiveness of a preliminary hull design, and optimize fin size and fin placement.
Following the CFD analysis, the next step is model testing. The first model tests are called roll decay tests that serve to verify the roll period and to determine the roll damping coefficient, with and without stabilizers. They also measure the fin performance and their motions, that will directly impact the system’s wear and tear and amount of service required.
So, what exactly is the benefit of all this testing? There are comfort indicators, including either the motion sickness incidence (MSI) or the comfort rating (CR), to evaluate the incidence of seasickness, and the effective gravity angle (EGA) to evaluate the postural stability and comfort. These comfort indicators are crucial to the yachting experience, not only for comfort, but also for safety, onboard functionality, and protecting the vessel’s assets/overall structure.
CFD modeling and model testing provide the data for Quantum to propose the best possible stabilizing solution, tailored to each project’s unique characteristics. Furthermore, the early availability of detailed predictions will reduce the number of design iterations, saving an enormous amount of time and rework dollars upon completion when fixes are costly. Think of it as an insurance policy that will save
you time and money.
For Quantum, being able to predict stabilizer outcomes in the very early stages is a tremendous advantage for the client and is a
more efficient approach to maximize onboard comfort.
This article was originally published in the May 2023 issue of Dockwalk.