FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1984
1984 - 0067.PDF
efficient aerodynamic shape leading directly to lower fuel burn. "Apply this kind of improvement to the entire airframe and you wind up with some impressive figures", he adds. The NAS computer will be put to work on materials and structures, too, intro ducing the interesting concept of aircraft that are optimised in all three of the major disciplines. This is way beyond the 1987 NAS level, but conceivable for the late Nineties, given the quantum leap in computing power that experts predict. The computer will be able to attend to flight dynamics routinely. While obvi ously applicable to civil transports, the most exciting benefits will be in the study of the operating envelope of fighters. A better understanding of the airflow around the aircraft, coupled with computation of structural limits, will mean extensions of the flight envelope to beyond even that of the coming generation of light combat aircraft. The NAS computer will also be directed to the prob lem of V/Stol fighter technology, currently the subject of debate in the USA and UK regarding the best powerplant/ airframe system for a Nineties machine. Nasa intends to offer the NAS facility to all of its branches, and to the US Department of Defence, industry, the universities, and other Government agen cies to make the best use of the new capac ity as what it calls "a necessary element in ensuring continued leadership in computational fluid dynamics". Up to 100 "customers" will be able to share time on the machine simultaneously. There are plans for a comprehensive country-wide data distribution network involving satellite and ground links. A key element of NAS will be the graph ics subsystem, the equipment that enables the supercomputer to communicate with the outside world. Huge amounts of raw data will need to be converted to suit humans using video terminals, printers, cassettes, and films. The 15min cycle time for calculating the viscous flow around an entire airframe will mean that a new generation of interface equipment will be needed. Graves says that discussions with companies working at the leading edge of this technology have led to a decision to leave procurement of the graphics subsystem until last, to take maximum advantage of rapid evolution. Approved funding for the NAS facility amounts to $17 million. A further $120 million will see the fully operational dual- processor system complete with all peripherals. The facility will be assembled at the Ames Research Centre, Nasa's lead centre for computational aerodynamics. A new building is under construction, and will be completed in late 1986. Until then the system will share existing space. The digital windtunnel is on the way. D This Nasa-produced table reveals various shortcomings in the results yielded by windtunnel testing. Nasa says that some of the consequences could have been avoided using today's computational techniques Aircraft C-141 C-5A F-111 B-58 B-70 YF-12 J F-102 F-106 Two Civil Transports Problems discovered in flight test Incorrectly predicted wing flow Incorrectly predicted drag-rise Mach number Incorrectly predicted transonic airframe drag Incorrectly predicted transonic performance Incorrectly predicted transonic drag Incorrectly predicted nacelle-wing interference Consequence Compromised performance, costly modifications Reduced wing fatigue life Costly modifications Reduced aircraft effectiveness Reduced performance Redesign required IS MORE asi •"•'^••u^M^'i mmu ,/.' &$!&& 'MM :„p ssitt aerospatiale ^olESJ** DIVISION ENGINS TACTIQUES •^^j* 2-18, rue Beranger - 92320 Chatitlon - France MM 38 * MM40 iliiJJB ;' ''^ii** AM 39 ^.b.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
