Washington beat

'Supercar' officials list most-wanted inventions

The government-industry program to build a "supercar" is looking for help from design engineers. Officials of the Partnership for a New Generation of Vehicles (PNGV) have come up with a long wish list of inventions. Especially sought are innovations that could make the four-stroke, direct-injection diesel engine feasible. PNGV seeks a system that will improve mixing and oxidation of particulate emissions during combustion without harming other emissions components. Also wanted: novel engine architectures that permit use of lightweight materials for major components and in-cylinder pressure and chemical sensors for accurate control. PNGV hopes inventors devise high-temperature turbines that will achieve thermal efficiencies near 40%. Very helpful would be a design that reduces the gap between turbine blades and casing. One suggestion is a high-temperature, high-resolution blade-tip sensor for active feedback control of blade track position.

Panel backs three-prong program for design of ship structures

How can the design of ship structures be improved? A unit of the National Research Council has some ideas. They are included among research recommendations for fiscal 1998-1999 in the biennial report of the Committee on Marine Structures. First, the panel calls for a series of "professional-quality" multimedia presentations. They would include design details of ships and other marine structures together with explanations of the design processes used in their development. The electronic productions would benefit all marine structural designers, but are expected to be especially useful to designers who enter the marine industry with a background in other structural engineering disciplines. The presentations would serve both as a study model and as a standardized basis for research. The panel also recommends a project to develop a reliability-based methodology for structural design. A third suggested project is to provide guidance to designers for meeting life-expectancy requirements for ship hulls.

Translators promise exchange between myriad CAD systems

A consortium of U.S. shipyards and CAD developers has successfully completed the initial phase of a three-year project that will produce the first ship product model translators. Called MariSTEP, the project uses prototype STEP (Standard for the Exchange of Product model data) translators. These will enable shipyards and ship design companies to exchange detailed information between dissimilar design systems, which is not possible using existing technology. The software allows CAD systems to both read-in and write-out common ship design data. The project is one of a series managed under the Defense Department's MARITECH program to promote advanced technologies in American shipbuilding. Another MARITECH-sponsored consortium will develop a computer system that integrates ship design, engineering, and manufacturing systems. This will be a first-of-its-kind system that uses COMPASS, a next-generation Windows-based CAD tool. The system will allow issues such as costs and refinements in building strategies to develop along side the ship design.

Tests on jetliner seek ways to reduce aircraft drag

Researchers for the National Aeronautics and Space Administration (NASA) have begun tests to improve the efficiency of commercial aircraft by minimizing aerodynamic drag. Since late spring they have been conducting the tests on a modified Lockheed L-1011 TriStar at Edwards Air Force Base, CA. NASA's Langley Research Center, Hampton, VA, is sponsoring the testing. Most tests will be flown at speeds of about Mach 0.83 at altitudes of 30,000 to 40,000 ft. For the experiment, a team of engineers designed a software program for the aircraft's research computer that reduces the aerodynamic drag of the entire aircraft. It does this by changing the positions of the aerodynamic control surfaces. By incorporating data such as airspeed, altitude, and engine measurements, the program makes instantaneous decisions on adjusting the position of the control surfaces to give the highest aircraft efficiency for each point in the flight profile.

Mobile x-ray unit can inspect small parts, detect threats

Engineers at the Naval Research Laboratory in Washington, DC, have developed a portable x-ray device. This Mobile X-Ray Unit (MXU) operates on an internal battery and weighs only 26 lbs. Its flash generator is an improvement over pulsed x-ray sources. Previous flash x-ray generators with rack-mounted power supplies weigh hundreds of pounds. The MXU battery can supply more than 150 pulses before needing a recharge. Because MXU employs short pulses of 50 nsec, it can image hard-to-get-to moving components as well as small, skittish animals.