1,487 research outputs found
Use of hydroelasticity analysis in design
No full textApplication of hydroelasticity analysis in various stages of the design process can provide improved predictions of global wave-induced loads, such as torsional moments for mono-hulled vessels and splitting and torsional moments for multi-hulled vessels, by modelling the physical problem more accurately. The complexities involved in generating the data for the fluid-flexible structure interaction (FFSI), on the other hand, can be considered as a disincentive to its extensive use by designers. This particular issue led to the work described in this paper on the application of 3D hydroelasticity analysis tool for the dynamic behaviour of ships in waves through the use of the G-Hydroflex portal. This web-enabled application allows users to solve FFSI problems by utilising large Grid based computer resources. The portal also allows geographically dispersed designers to work together with ease and security.
Following the description of the portal architecture, applications to a range of mono- and multi-hulled vessels are illustrated and further improvements discussed
New technology for interactive CAL: The origami project
No full textOrigami is a three‐year EPSRC project that forms part of a general research programme on human‐computer interaction. The goal of this research is to investigate and implement new methods for human‐computer interaction, and to apply and evaluate their use. The research centres on the DigitalDesk, an ordinary desk augmented with a computer display using projection television and a video camera to monitor inputs. The DigitalDesk allows electronic and printed documents to be combined to give richer presentation and interaction possibilities than are possible with either separate medium. This paper examines the implications of such a system for CAL, and presents two prototype applications that demonstrate the possibilities
Solution of the problem of composite charge using R.D.38
No full textIn this paper the author has solved the problem of internal ballistics of composite charge using 'R.D.38' method which is based upon the usual isothermal approximation. A linear law of burning has been assumed
Author index
No full textThe articles have been scanned in colour with a HP Scanjet 5590; 300dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.This is a continuation of the "Author and Subject Index to the Onderstepoort Journal
of Veterinary Science and Animal Industry (1933- l950)" and the "Onderstepoort Journal
of Veterinary Research (1951 - 1968)" which appeared in June 1969 and covers the period
1969 to 1973, i.e. Volumes 36 to 40.
As from 1974 (Volume 41) it is intended to furnish an Author and Subject Index
in Number 4 of each volume covering all four numbers for that particular year
Noise due to unsteady flow past trailing edges
No full textThis paper presents two-dimensional direct numerical simulations (DNS) of noise generated at trailing edges (TE) with zero thickness. The simulations are conducted specifying either no-slip or slip walls in order to investigate viscous effects. In both cases, small amplitude disturbances are introduced close to the inflow boundary that serve as pressure disturbances at the TE. DNS data reveals that the unsteady Kutta condition is not satisfied, irrespective of the wall boundary condition. However, it appears that the validity of the unsteady Kutta condition is not essential for making an accurate prediction of the far field noise. The far field pressure is predicted as a function of the surface pressure difference using a 2-D modification of Amiet's classical theory, and compared with the far field pressure computed directly. Directivity plots provide evidence that the presence of boundary layers and noise generated by an unsteady wake in the no-slip cases lead to smearing of individual lobes, and that the downstream pointing lobes in no-slip wall cases are probably due to nonlinear noise generation in the wake. The simulations are conducted using a high-order accurate numerical method which is free of upwinding, artificial dissipation or any form of explicit filtering, and employs a novel boundary treatment
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