The National Aero-Space Plane (NASP) program has a wide range of technical challenges associated with it. In the process of finding solutions to these unknowns, NASP has enabled advancements across a broad scope of technologies. This state-of-the-art work is being performed by 5 major aerospace companies (Lockheed Ft. Worth, Rockwell International, McDonnell-Douglas, Pratt&Whitney, and Rocketdyne), over 400 subcontractors (including universities) and 15 major U.S. government research laboratories. This variety of affected technologies and large extent of interaction with national organizations are building an important foundation for U.S. technological preeminence in a variety of industries; most notably being the aerospace, energy, medical and automotive industries.
The NASP Technology Applications Integrated Product Team (IPT) is pursuing technology transfer in all of these industries. With respect to the automobile industry, the team is planning to design, build and test a NASP technology demonstration automobile engine with revolutionary characteristics such as, high efficiency, low emissions, high temperature capability, higher power and lighter weight. The IPT, which is charged with lowering the cost and increasing the performance of future hypersonic systems, believes that everyday usage of the NASP technologies in applications such as the automotive industry will ensure cheaper, ready availability at a later date.
The purpose of this paper is to outline the NASP interest in technology transfer, describe the NASP technologies and capabilities are applicable to the automotive industry, describe the NASP Joint Program Office (JPO) reasoning for choosing the automotive industry, and outline the NASP technology demonstration automobile engine project.
Technology transfer is defined by AFMC/ST as the dissemination of technology to applications outside of the government. Transfer can be contrasted with transition which is dissemination of technology to applications within the government. The NASP program became interested in technology transfer and transition in 1989. The reasoning being threefold: (1) to lower the costs of existing and future systems, (2) to increase the performance of existing and future systems, at a lower risk to the developing agency, and (3) to keep the research and development base strong.
Technology transfer lowers the costs of existing and future systems by exploiting commercial markets. These markets are characterized by higher volumes than the general government system application. Volume tends to increase learning and amortize fixed costs more evenly. Additionally, the commercial application provides test data that may be useful to the government application. As the commercial venture operates in the marketplace, the spin-off technology might be enhanced to account for competition. All of which could eventually spin-back to the government in a more useful fashion.
Technology transfer provides a similar advantage to performance as it does to cost. By generating useful alternate applications of the NASP technology, the IPT is facilitating the development of higher performing government systems. This is accomplished predominantly through the different requirements of commercial products. These new requirements, though rarely more demanding than the government application, may analyze or task the technology in a variety of ways. Again, all of this is potentially useful information to the government developing agency.
Finally, NASP technology transfer serves to make additional use of the research and development infrastructure, especially in lean economic times. Successful cultivation of commercial applications of government capabilities serves to preserve facilities and engineering talent and expertise. Research and development capabilities can not be resurrected in an on-demand basis, and generally take several years to develop. Useful alternate applications of these government tools will ensure their readiness when they are called upon again by the government.
The materials science area of NASP technology applications has been extremely successful. There have been many advances in metal alloys including TIMETAL™ 21S Titanium, Gamma Titanium Aluminide, and Aluminum-Beryllium (AlBeMet™). Development has also occurred with titanium and titanium aluminide metal matrix composites, thermo set/thermo plastic materials, and metallic coatings.
This material was developed for use in NASP metal matrix composites and it is 100 times more corrosion resistant than “standard” aircraft titanium. This advance in characteristics was achieved without sacrificing the high strength and temperature capabilities of other current alloys.
TIMETAL™ 21S has many benefits which make it highly adaptable to a variety of industries. As stated earlier, this particular material exhibits a very high corrosion resistance, while at the same time maintaining an impressive strength-to-weight ratio. The material possesses a better cold and warm formability than conventional titanium alloys and is also strip producible, meaning it can be economically rolled to a foil.
TIMETAL™ 21S use is anticipated in the oil industry. One application is to use this material in piping for sour oil and gas wells. Because of the attractive anti-corrosion properties of this titanium alloy, it is expected to withstand the corrosive sulfuric acid gases found in sour wells. Test pipes for these wells have already been produced. Another significant advantage of TIMETAL™ 21S, is that at nearly half the weight of “ordinary” titanium, a deeper well can be drilled. Depths of 30,000 feet are now achievable (versus 20,000 feet for current steel-clad pipe), and give access to a greater number of oil and natural gas sources available for tapping. The lightweight advantage also allows the use of a larger diameter pipe and enables the flow rate to be increased by up to 50 percent. Another application which has great potential for TIMETAL™ 21S is its use in platform bolts for offshore drilling structures. The nickel-based superalloy bolts currently in use on these oil platforms require a biannual replacement weighing 2 million pounds. The labor cost to replace these bolts is one of the major expenses of this process. The corrosion resistance of this metal would substantially extend the life of the platform bolts and reduce the maintenance cost of the platforms. There is a potential 100 million pound market for the platforms in the North Sea alone. TIMETAL™ 21S is baselined into the nacelles for the upcoming Boeing-777, replacing the superalloys currently being used, to prevent corrosion hazards associated with various leaks. The lightweight characteristics of the titanium will also enable a potential weight savings of 850 pounds per engine. In terms of dollar amount savings, a Life Cycle Cost savings of more than $3-5 million per aircraft has been projected, as well as a fleet savings of potentially a half billion dollars.
The potential also exists for TIMETAL™ 21S to be used in the medical field as human implant material for applications such as prosthetic joints, pacemaker components, and orthopedic wire. This application would allow up to 30 to 50 percent fewer surgical procedures. The titanium alloy's elasticity is closer to that of human bones and would provide a more natural joint for the recipient.
Heat exchanger requirements for the NASP have sparked a renewed interest in a beryllium alloy not used since the 1960s when production was ceased by the original manufacturer. NASP requirements have not only improved the characteristics of this material, resulting in a much better manufacturing process, but also significantly improved its characterization data base, enabling it to be looked at for commercial applications. The new NASP-developed alloy is trademarked AlBeMet™ 160. Some benefits of this material include both high strength and low density. AlBeMet™ 160 has been demonstrated to have excellent thermal conductivity which will enhance the component life.
AlBeMet™ 160 has already demonstrated its capability to produce both commercial and government spin-offs. The major spin-off to date is in the area of computer technology. A rotary actuator for a high-performance computer disk drive is being manufactured with this material because of its attractive physical properties. AlBeMet™ 160 provides a lighter, stiffer, and thinner disk drive actuator arm than those made in the past with other materials. The overall benefits of this new actuator include a more rapid access time to data stored on the hard disks, as well as me capability of doubling the density through more precise arm placement. Firm orders have already occurred, with a potential market for this application in excess of $100M. This shows the initial investment of $657,000 made by the NASP program to have a return on investment of over 200 to 1.
NASP research lead to the application of Martin Marietta XD™ process (the synthesis of composites with in situ precipitation of reinforcements) to the production of gamma titanium aluminide. This process enables lower cost and much higher strength uniformity compared to other composites. It is important to note that only button size elements existed before NASP was involved, but now castings of up to 10,000 lbs are possible. NASP assistance also contributed to the application of the XD™ process to other titanium aluminides.
Small-engine impeller test pieces have already been manufactured with gamma titanium for use in gas-turbine engine and automotive turbochargers. There is also a single piece compressor stage currently being developed for a cruise missile engine. The light weight, high-strength and high-temperature benefits of XD™ gamma titanium contribute to a faster spin-up and operating speed for lower altitude launches, while at the same time allowing them to be manufactured at a lower cost than previously used materials.
A gun blast diffuser for the F/A-18 aircraft has been produced as a replacement component. Its benefits include: (1) increased erosion resistance and (2) a 40 lb weight savings accredited to this component.
Another potential spin-off involves the automobile industry. TiAl auto exhaust valves have been produced for testing by some major automotive companies. The benefits of these valves are: (1) a 50% weight reduction over the current valves, (2) a 500 RPM increase in engine speed contributing to an economically sound manner of increasing engine performance, and (3) an overall lighter engine with increased efficiency.
While the NASP program did not invent this computational technique, it did contribute significantly to the improvement of CFD over the past five years. The driving force behind NASP involvement in CFD came from research in supersonic/hypersonic flows around complex shapes with excessive variance in aerothermochemistry, flow injection, and/or thermochemical boundary interactions. More generic breakthroughs were made in the areas of grid generation and mechanisms for matching computational results with more complex experiments for use in code validation.
It would be unfair to assess the NASP contribution to CFD solely on direct applications to the field. NASP has had a much larger impact on the indirect advancement of CFD by greatly accelerating its overall growth. Thousands of hours of NASP funded super computing and code validation work are mostly responsible its the enormous impact on the development of this subject.
NASP has contributed to the advancement of CFD across a broad range of areas. First, the program developed higher-order predictive tools to simulate complex fuel injection, mixing, and combustion for its combustion research. These techniques are already being applied to the automotive, aerospace, and electrical power generation industries in order to gain better efficiencies and lower pollution rates.
The complex design configuration of the NASP caused researchers to look more closely at creating detailed analysis tools for calculating complex aeromechanical/aerothermal interactions. Tools such as these are now finding their place in the aerospace world, saving time and money by reducing the required amount of testing.
NASP technological demands have also been responsible for new CFD codes, as well as upgrading the existing codes. One example is the SPARK code, which was created by NASP to analyze a 3-D supersonic flow, is currently being used to analyze various parameters of the High Speed Civil Transport. This code, along with other aerodynamically oriented ones developed for NASP, enables a more efficient way of designing aircraft through a reduced dependence on wind-tunnel testing.
Douglas Aircraft used the NASP Integrated Structural/Thermal Analysis Program to obtain an acceptable design for an upgrade in the F-15 heat exchanger. Repeated failures with previous designs were causing problems with the cost and delivery schedule for the upgrade effort, until the NASP-developed code was able to solve the design problem. This tool saved significant labor, test time, and procurement cost.
The NASP Technology Applications IPT decided to focus on the automotive industry as a result of several feasibility studies conducted in the 1986 to 1990 time frame. These studies matched available NASP developed technologies with appropriate industries. One of the most compelling marriages was the materials and processing technologies developed as part of the NASP with the automotive industry. The studies cite a variety of reasons for this marriage: (1) the trade deficit between the United States and foreign competition, (2) the automotive applications require many different levels of material technologies, (3) the volume potential of the automotive industry, and (4) the challenging requirements of the automobile industry.
The NASP technology demonstration automobile engine will satisfy these goals and objectives. It will provide a mechanism to demonstrate the revolutionary capability of a wide array of NASP technologies. The automobile engine is performance driven, thereby providing the opportunity to enhance the current technologies: especially in processing costs, promoting technology spin-back to the government. The demonstrator project will also speed the transfer of the technologies because it provides a real world application with benefits assessment and metrics comparisons with existing engines.
The NASP Technology Demonstrator Automobile Engine project goal is to design, construct and manufacture a revolutionary light-weight, compact, fuel-efficient, environmentally compatible engine with NASP technologies. The plan is not to “out-do” the engine companies, but to join with them to demonstrate the capabilities of aerospace technologies in their industry.
The engine will be developed by leveraging the capabilities of several groups from industry and government. The industry groups include both NASP technology developers, automobile companies, and engine designers. The government participants include the Department of Defense and potentially other departments interested in light weight, efficient automobile engines. Each member will bring particular expertise to the group, such as materials, engineering talent and funding. Texas Instruments of Attleboro, MA will serve as the project integrator for the effort, as well as contributing the NASP developed isobaric rolling and processing technology to the project.
The engine project is expected to be a 24 month project. The first six months of the project are devoted to conceptual design and consortium forming. Other tasks during this period include development of an engineering data base for the NASP materials, risk analysis, engine system requirements, and projected engine system performance. Additionally, the consortium will be involved in significant outreach activities to attract more consortium members.
The following 6 months will involve detail design and component manufacturing. The components will be fabricated predominantly from NASP materials. For instance, the consortium plans on using materials such as High Temperature Aluminum to replace regular aluminum and cast iron in the heads and block. They are also considering materials such as the Aluminum-Beryllium, Titanium-Aluminides, TiMetal™ 21S, and carbon-carbon composites for other parts of the engine. The final phase of the project includes assembly and test of the completed engine.
The engine is being designed to take advantage of the revolutionary capabilities of the aerospace materials developed for NASP. Materials with very light-weight, high-temperature and corrosion resistance will contribute enormously to increasing the performance of everyday engines. Initial projections of the benefits of the engine include a 50% reduction in weight, 200 horsepower capability, 1 to 2 liter displacement, an increase of 20% in efficiency, and a substantial reduction in emissions. The envelope of efficiency and cleanliness of operation is determined by the reduction in reciprocating and rotating weight and mass, as well as higher operating temperatures. The NASP engine will score a direct hit on both of these parameters.
The technology developed for the NASP Single-Stage-to-Orbit (SSTO) program is finding its way into a variety of applications from the information processing industry to the medical industry. Product innovation and improvement are the hallmarks of the Technology Applications IPT. These enhancements not only serve the commercial sector, but they spin-back to the government in the way of cheaper, higher performing systems and components. The NASP Technology Demonstration Automobile Engine serves as a project to showcase the revolutionary capabilities of the NASP aerospace technologies as applied to the automobile industry. The benefits of the enterprise are lighter weight and higher temperatures. Interested consortium members should contact either Major Bill West or 2Lt Jennifer Mitchell, at 513-255-3165.