Six-stage compressor program
Munich-based MTU Aero Engines is progressing development of its HPC12 experimental compressor. It is a six-stage transonic high-pressure compressor with a pressure rise capability of 11:1 and is designed as a fully functional engine component. The company reports that in a two-week trial simulating harsh conditions in a service environment, the compressor delivered "outstanding results." The two-week test included pressure ratio, airflow efficiency, surge margin, and other performance elements. MTU said that it used 3-D aerodynamic design techniques to achieve optimal compressor efficiency and robustness "even at high stage pressure ratios." It added that 3-D design "appreciably lowers" manufacturing and maintenance costs over comparable current compressors: "These costs are crucial criteria, especially in medium- to long-haul service."
The HPC12 program includes the development of highly heat-resistant materials for the final two compressor stages. On the basic HPC 12 work, MTU is cooperating with the DLR (German Aerospace Center) and with academic institutions.
 The HPC 12 is prepared for a test run at MTU's Munich, Germany facility. |
Next month, MTU is scheduled to ship the first production EJ200 engines to be installed in the special Eurofighter IPA (Instrumented Production Aircraft). By 2005, a total of 363 engines are scheduled for delivery to power Eurofighters. Production engines were tested at Rolls-Royce (UK), FiatAvio (Italy), ITP (Spain), and by MTU itself.
Meanwhile, MTU is continuing its development of a new family of geared turbofan engines in partnership with Pratt and Whitney and FiatAvio via the Advanced Technology Fan Integrator (ATFI) program. The powerplants would be for large business jets and regional jets, and the target is to offer enhanced economics together with lower noise (30db(A) less than Stage 3 requirements) and emissions levels. The program has the additional aim of reducing manufacturing costs by some 30% compared to current ungeared turbofan engines together with lower life-cycle costs. Power output is likely to be at two levels: 10,000 lb for 50-60-seat aircraft and 18,000 lb for 100-seat airplanes.
According to the company publication MTU Report, the partnership is working in anticipation of requirements for an ATFI powerplant. Martin Wiedra, Senior Manager, New Products at MTU stated, "We want to use the demonstrator program to mature the technology to a point where we can promptly convert it into a new product when the time and market have come for it."
MTU sees business jets being introduced that have wider fuselages able to provide added comfort and believes this development will lead to the need for advanced, economical engines using geared-fan technology. Future upgrades of current business jets might also offer opportunities.
The company explains the concept of the geared fan as interposing a reduction gear between the fan and low-pressure turbine, "which in today's engines are on a common shaft and necessarily rotate at the same speed," but can then each run at its own optimum speed, which for the fan is lower than for the turbine. "What the ATFI demonstrator is to prove is that an engine with a high-speed, low-pressure turbine transmitting its power to the fan through a gearbox will distinctly improve consumption, noise levels, and, above all, costs," said MTU.
MTU's particular role in the program is development of the high-speed, low-pressure turbine. The company has noted expertise in this area and is confident that it can reduce the number of turbine stages and therefore cut weight and manufacturing costs. Experience gained within the Engine 3E technology program (previously described by Aerospace Engineering, it is German industry/government-funded) is benefiting from the work.
To cope with the unparalleled high powers and temperatures, MTU is developing new blade materials and airfoils as well as new rotor concepts and brush seals for the high-speed low-pressure turbine. The company said that the low-pressure turbine's development and production content in the overall program is about 25%. According to MTU, that stake might grow appreciably if the company manufactures the high-pressure turbine as well, an option that is currently being discussed.
- Stuart Birch
Raptor tests new avionics and radar
 The F-22 Raptor team is finishing up various flight tests to meet the Defense Acquisition Board's requirements for a decision on low-rate production. |
The F-22 Raptor 4005 made its first flight equipped with combat-capable avionics from Lockheed Martin's facility in Marietta, GA. Representing one of the three remaining tasks required prior to a decision on F-22 low-rate production, the flight incorporated Block 3.0 software components, which provide functions such as radar processing and sensor fusion, electronic warfare and countermeasures, communication, navigation and identification, and pilot/vehicle interface.
"Block 3.0 is the software that provides and controls the 'first look, first shot, first kill' warfighting capability of the F-22 Raptor," said Tom McDermott, Lockheed Martin Aeronautics' F-22 Avionics Product Manager. "Block 3.0 provides the multisensor fusion Raptor pilots will need to accurately acquire, track, identify, and engage multiple targets." In addition to Block 3.0's ability to launch and guide multiple weapons such as the AIM-120 and AIM-9 air-to-air missiles, the software package enables the aircraft to automatically detect and defeat incoming missiles by initiating the Raptor's countermeasures.
The Boeing Co. integrates and tests the Raptor's avionics at the Avionics Integration Lab in Seattle and on the Flying Test Bed. Both the lab and test bed are helping reduce avionics risks and contain development costs by enabling extensive evaluation and troubleshooting before full avionics are installed on the F-22.
Also making its first flight this month was the F-22's active electronically scanned array (AESA) radar onboard Raptor 4004. A Northrop Grumman-led joint venture with the Raytheon Co. has been developing the radar system for more than 10 years. In addition to sharing hardware fabrication and assembly with Raytheon, Northrop Grumman is responsible for the overall design of the AN/APG-77 radar system, including the control and signal processing software. It also has the responsibility for radar systems integration and test activities.
The main component of the radar sensor is a highly reliable AESA, which provides the rapid beam agility, low-radar cross section, and target detection capability that enables the air dominance fighter to achieve its "first look, first kill" capability. In addition to the AESA, the radar sensor subassemblies include a radar support electronics unit similar to a traditional receiver/exciter, a radio frequency receiver unit, an array power supply, an aircraft installation kit, and a coolant distribution manifold.
According to Northrop Grumman, all 11 engineering and manufacturing development radar systems have been built and delivered on time and within cost projections. A total of 339 F-22 aircraft are planned. If approved, low-rate initial production of the radar is expected to begin in the first quarter of 2001.
The decision to enter low-rate production on the Raptor rests with the Defense Acquisition Board (DAB) chaired by the defense undersecretary for acquisition and technology. The program was on schedule to complete the DAB requirements by the first week in January until several snowstorms hit the area, postponing the tests until the following week.
- Frank Bokulich
Rapid prototyping by Tecan
Speed and accuracy in making prototype parts is an essential element in meeting product development schedules. Tecan Components in Europe has aimed to cut the time to a minimum and has now established a five-day prototyping service aimed particularly at design engineers, including those in the aerospace industry that deal with small sheet-metal parts. No part will be offered unless it has already been proven that it can be achieved, stated the company. "This often results in leading edge solutions, with niche advantages being produced, an example being a selectively gold-plated lead-frame for an optoelectronics application."
Tecan said that the advantage of its rapid prototyping philosophy is that in addition to the speedy delivery of the first low-volume parts, once they are adopted, down-the-line production speeds and costs are reduced because the tooling is already in place. "Future modifications can be cost-effectively incorporated, if necessary, using the company's CAD system, ensuring any Ôknock-on' tooling costs are also minimized." The company adds that all parts are produced within an ISO 9002 quality-control regime.
- Stuart Birch
