COMPUTATIONAL FLUID DYNAMICS: an Applications Profile from Convex Computer Corporation
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COMPUTATIONAL FLUID DYNAMICS: An Applications Profile from Convex Computer Corporation This simulation. which is based on a Navier-Stokes analysis. depicts surface This simulation shows surface pressure predictions for the AV-88 Harrier II pressure predictions for the F-15 Eagle at Mach 0.9. forebody at Mach 0.8. Supercomputer simulations permit the engineer to observe phenomena that The AV-88 Harrier II can operate from small. unprepared sites and roads close wind tunnels cannot produce. to front Jines. Supercomputing performance brings large-scale simula effective resource for innovation, evaluation and enhancement tions into the aircraft designers repertoire. While not expected of aircraft design. to replace such traditional design tools as wind tunnels and test Design development using supercomputing simulation pro fiights, computer simulations offer the manufacturer a cost- ceeds from a systematic knowledge base rather than from conjecture or surmise. At the same time, computer simulation investigating the possibilities, MCAIR selected the Convex Cl, the increases the scope for design innovation and enhancement. first affordable supercomputer Its strong price/performance ratio The use of simulations makes iterative design experimentation proved decisive. cost-effective. Moreover, si mulations point the way to improve The Cl combines memory and vector processing capabilities ments in design. previously found only on large-scale supercomputers with the Supercomputer simulations also permit software and price advantages of minicom the engineer to obseNe details of fluid flow puters. MCAIR found that the Cl completed phenomena that wind tunnels cannot pro in 30 minutes runs that required hours on a duce. These include surface pressure dis "Computational fluid minicomputer tr i bu ti on s, shock wave locations and dynamics is more complex for Installed in September 1985, this 64-bit strengths, streamline paths and boundary military aircraft than for integrated scalar and vector processor with a layer behavior. In addition, simulations Cray®-like architecture ensured MCAIR a provide critical guidance - before costly transport aircraft and we've superior resource for developing and testing wind tunnel testing - concerning the need found the CJ equal to the code to run on the Cray and location for specific flow diagnostic challenge. Its an ideal The Cl s large physical memory, up to 128 measurements. platform for development of megabytes, provided the capacity to handle Finally, computer simulation has extraor code to run on the Cray: it's a larger models. dinary value in training. vector machine, it's open and The Cl at MCAIR is linked to a VAXclus The novice engineer who works with it's interactive. The CJ is also ter ™ which in turn is linked to the Cray simulations quickly acquires direct experi easy to manage, even in an In day-to-day use, MCAIR has found that ence w ith a broad range of design alterna the Cl delivers performance up to 20 times environment such as ours in tives and develops a lasting appreciation of that offered by the VAX TM 780. Moreover, the impact of design changes. which two departments are having supercomputing power on-site The result, for companies that exploit this sharing CPU time:· enables MCAIR to avoid the lengthy turn new technology, is superior design. Dr. August Verhoff, around times frequently associated with THE PROBLEM Section Chief, Technology time-sharing. In 1984, M cDonnell Aircraft (MCAIR), a The Cl operating system, Convex division of McDonnell Douglas and a lead Aerodynamics, McDonnell UNIX®, is enhanced for scientific and engi ing manufacturer of state-of-the-art military Aircraft Company neering users. In addition, Convex can sup aircraft, undertook a search for a computer "We have to maintain a ply an attractive library o f third-party system that would improve its capabilities for quality development software, math libraries and software tools. development of computational fluid program within stringent The Cl s 110 processors ensure that CPU dynamics code. The primary users of the time is not occupied with user and other 1/0 new resource would be MCAIR~ aero budget limitations, and thats A high 1/0 bandwidth to disk and a disk dynamics and propulsion-thermodynamics what makes the CJ such a striping facility enable the Cl to sustain high departments. winner here. We save 110 performance levels. The requirements involved were exacting. tremendously in not having THE ORGANIZATIONS The principal need was a system that would to do time-sharing for code McDonnell Aircraft Corporation manufac allow MCAIR to sustain its outstanding development. In fact I get tures high-performance aircraft for military development program while controlling its SS00,000 in value each year customers including the U.S. Navy. the U.S. costs. MCAIR prides itself on its commitment Marine Corps, the U.S. Air Force, the National to investing in the future while achieving from the CJ, and I only Guard, the Royal Air Force, and the govern better quality. higher productivity and account for half of its use. ments of Australia, Canada, Israel, Japan, reduced costs. Whats more, we expect the Spain and Saudi Arabia. MCAIR is the home To call a halt to the continuing expense of CJ to be able to handle the of the F-15 fighter, which recently achieved time-sharing on a Cyber ™, the company development load for at least the millionth flight-hour milestone with the resolved to make a sound capital investment another two years:' best safety record of any fighter in the history in a machine that could be located on-site of the U.S. Air Force. Based in St. Louis, Mis and fully loaded without incurring user fees. Raymond R. Cosner; souri, McDonnell Aircraft is part of M cDon Because work in computational fluid Unit Chief, Propulsion - nell Douglas Corporation. dynamics is CPU-intensive, even in test cases, Thermodynamics Convex Computer Corporation, head MCAIR also demanded a machine that was Department McDonnell quartered in Richardson, Texas, was founded top-rated. on a dollars per calculation basis. Aircraft Company in September 1982 to design, manufacture, In addition, since the planned system market and seNice affordable supercompu would be used to develop code that would ters. The Convex Cl, which features a Cray run on the Cray-1 TM, MCAIR needed a power like architecture, combines 64-bit scalar and ful vector processing machine. vector processing capabilities of large-scale supercomputers THE SOLUTION with software and price advantages of minicomputers. Offices These requirements considerably narrowed the range of alter worldwide ensure service and support to customers using natives. Their high costs quickly put Cyber machines out of the Convex systems for geophysical research, computer-aided engi running. Their slower speeds ruled out minicomputers. After neering and design, defense, aerospace and general research. Convex and the Convex logo are trademarks of Convex Computer Corporation. Cyber is a trademark of Control Data Corporation. Cray is a registered trademark and Cray-I is a trademark of Cray Research. Inc. VAX and VAXcluster are trademarks of Digital Equipment Corporation. UNIX is a registered trademark of AT&T Although the material contained.herein has been carefully revievved, Convex Computer Corporation (Convex) does not warrant it to be free of errors or omissions. Convex reserves the right to make corrections. updates. rev1s1ons or changes to the information contained herein. Convex does not warrant the material described herein to be free of patent infringement. Convex Computer Corporation. 701 North Plano Road. Richardson. Texas 75081 (214) 952-0200 Publication 080-002187-000 11/86 Printed in the U.S.A. .