Year: 2015
Type: dataset
Abstract: Recent advances in high-speed computing have benefited the field of computational fluid dynamics.Ship designers can now analyze by computer complex water-and air-flow behavior, previously poorly understood through expensive and timeconsuming testing with scaled ship models.These improved computational fluid dynamics techniques are revolutionizing the ship design process and enabling better designs to be produced more quickly.This article provides an overview of the use of computational fluid dynamics in ship design; and then its use, along with theory and experiment, in design of sailing vessels for racing. Computational Fluid DynamicsShip design is an evolutionary process where the designer largely relies on past experience.As in all design work, the final product is a compromise between conflicting demands, and in the hydrodynamics area the main trade-off for merchant ships is between large loading capacity and small power consumption.Important constraints are the length of the ship, which strongly affects the production cost, and the speed required to meet the intended schedule.Further, the ship has to be seaworthy and have adequate maneuvering capabilities.The traditional tool available to the designer, apart from empirical data, is water basin experiments, where a scaled model of the ship is tested under self-propelled or towed conditions.This is an expensive and time-consuming process which needs to be carried out at the initial design stage.Since many other design problems cannot be solved without knowledge about the shape of the hull, time is especially critical at this stage.Therefore, there is great interest in another approach, taking advantage of the developments in computational fluid dynamics. RANS methods and panel methodsAll flows of interest in ship hydrodynamics are governed by the Navier-Stokes equations, which express the relation between the three components of velocity and the pressure.The computer power required for their solution is prohibitive, but a modification known as the Reynolds-averaged Navier-Stokes (RANS) equations is often quite useful.These equations must be solved with a suitable model for the turbulence.To further reduce the computational effort, it may be assumed that the flow is frictionless, which is a good approximation if the immediate neighborhood of the hull is avoided.Under this assumption, the velocity may be represented by a potential governed by the Laplace equation.In practice the problem is often solved by taking advantage of the linearity of the Laplace equation and superimposing elementary solutions to the problem on panels on the hull and (in most methods) on the free surface.These panel methods are considerably faster than the more exact RANS methods and are much more used at present.In the following, the use of the two methods is presented for each of the four main areas of ship hydrodynamics, namely resistance, propulsion, seakeeping, and maneuvering.Resistance
Source: AccessScience
Authors: Larsson, Lars, Milgram, Jerome H.
Language: English
Subfield: Ocean Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2566068363