FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
2003
2003 - 1939.PDF
Future of Engines %^ FLIGHT mance, against which data on pressures, temperatures and speeds will be compared. A key target for new engines will be the use of smart structures, materials and sen sors combined with advanced control algo rithms to mimic the responsiveness of a living organism. Active compressor stabili sation, for example, could control post- stall behaviour in the event of a sudden throttle change. Using smart algorithms, response settings and actuation, the oper ating point can be moved to the stall line and back. With this ability, designers will drive stage loading up significantly. This should be good news all round. Because the trade between pressure ratio and stability margin will be simplified, actively controlled compressors will be eas ier to develop. Fewer design iterations will cut development costs, and reducing the compressor stages will trim manufacture and maintenance costs. Elimination of stall and surges will lead to the develop ment of maintenance-free compressors. Similar "intelligent engine" concepts include active blade vibration control and active combustor control. Engine versatility may also embrace variable-cycle systems, which could be the next major innovation to the jet engine. Variable-cycle engines tune bypass and pressure ratio to the unique mission requirements, while all propulsion systems are designed for the critical point in the mission. This could be take-off power, take off noise, acceleration or cruise. The con cept could provide more efficient opera tion than the current fixed cycles. Along with versatility and intelligence, a third focus area is durability. A major part of the drive for affordability will be pre- A key target for new engines will be the use of smart structures, materials and sensors venting component failure, increasing engine life and reliability, and making them easier to repair. To make this possible, engines of the future will move towards high-speed, high-temperature, oil-free tur- bomachinery using technology such as foil bearings and tribological coatings. NASA is also examining the potential advantages of an oil-free rotor system as part of Glenn Research Center's aerospace propulsion and power programme. The aeropropulsion programme offers a blue print for NASA's vision for the 21st century and, in common with many engine mak ers and global study groups, sees a gradual shift from today's reliance on chemical combustion energy, through a phase of hybrid systems to a largely electrochemi- cally-based aerospace world. The first steps toward these greener engines involve the experimental develop ment of fuel cell-powered unmanned air vehicles and general aviation aircraft. Fuel cells are electrochemical devices that con vert hydrogen directly into electricity and heat without combustion, making them more than twice as efficient as an internal www.flightinternational.com FLIGHT INTERNATIONAL 9-15 SEPTEMBER 2003 41
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
