Numerical Project Research Articles

Distributed Interactive Graphics Applications in Computational Fluid Dynamics

Implementation of two distributed graphics pro grams used in computational fluid dynamics is discussed. Both programs are interactive in na ture. They run on a CRAY-2 supercomputer and use a Silicon Graphics Iris workstation as the front-end machine. The hardware and supporting software are from the Numerical Aerodynamic Simulation project The supercomputer does all numerically intensive work and the workstation, as the front-end machine, allows the user to perform real-time interactive transformations on the displayed data. The first program was written as a distributed program that computes particle traces for fluid flow solutions existing on the su percomputer. The second is an older post-pro cessing and plotting program modified to run in a distributed mode. Both programs have realized a large increase in speed over that obtained using a single machine. By using these pro grams, one can learn quickly about complex features of a three-dimensional flow field. Some color results are presented.

Comments on the IFIP working group 2.5 proposal on "parameterization of the environment for transportable numerical software"

IFIP Working Group 2.5 has proposed a set of parameters for describing the computing environment. This proposal appeared in the SIGNUM Newsletter [1], and simultaneously in several other journals. It is unfortunate that this paper is presented as a consensus view, when no reference is made to earlier published work on similar parametrizations (see especially [2] and [3]). There certainly is a clear need for a way to parametrize details of the computing environment. At present, each large numerical project uses its own set of parameters. A generally used and available set of such quantities is certainly long overdue. The numerical community should certainly propose and even adopt a set of its own, and it is laudable that the IFIP Working Group 2.5 has taken this task upon itself. However, I disagree with many of the details of the proposal.

Modeling of Cumulus Initiation in METROMEX

Abstract A numerical cloud modeling project has been initiated as part of METROMEX. A two-dimensional time-dependent model of a vertical slice of the atmosphere has been applied to investigations of cumulus initiation in the St. Louis area on 7 and 10 August 1973. The results indicate that on these days the urban-related surface temperature distribution was a significant factor in determining the location of cumulus initiation. This result is supported by field observations from METROMEX.

Continuing numerical data projects. A survey and analysis edited by M. G. Buck

Continuing numerical data projects. A survey and analysis edited by M. G. Buck