National Aeronautics and Space Administration
Small Business Innovation Research 2002 Program Solicitations

TOPIC A2 Vehicle Systems

[ back to Solicitation ] [ back to Chapter 9.1.1 ] [ back to Chapter 9.1 ] [ back to Chapter 9 ] [ back to table of contents ]

A2.01 Propulsion System Emissions and Noise Prediction and Reduction
A2.02 Electric and Intelligent Propulsion Technologies for Environmentally Harmonious Aircraft
A2.03 Revolutionary Technologies and Components for Propulsion Systems
A2.04 Airframe Systems Noise Prediction and Reduction

The Vehicle Systems Program within the Aerospace Technology Enterprise is developing revolutionary technologies at the laboratory, component or subsystem level, relying on strategic partnerships and opportunities with the aerospace industry and other government agencies, for further technology maturation and application. To ensure the technologies developed in this program are at an appropriate readiness level and the objectives of the program are met, the program will provide investments for significant advancements in critical components and designs. The overall progress of Vehicle Systems will be determined based on analytical integration of the technologies into system level assessments against the Enterprise's Revolutionize Aviation Objectives - Enable the safe, environmentally friendly expansion of aviation. Three projects: Breakthrough Vehicle Technologies, Propulsion & Power, and Flight Research focus on development of the fundamental technologies needed to enable the change state in aeronautics. The three projects: Ultra-Efficient Engine Technology, Quiet Aircraft Technology and 21st Century Aircraft Technology focus on the integration of these technologies into subsystems and systems that can be developed with industry partners into high leverage products. The Advanced Vehicle Concepts project takes those vehicle and technology concepts which require flight testing through additional systems analysis, concept development and research flight testing.

A2.01 Propulsion System Emissions and Noise Prediction and Reduction
Lead Center: GRC

Emissions: Current environmental concerns with subsonic and supersonic aircraft center around the impact of emissions on the earth's climate. Carbon dioxide (CO₂) and oxides of nitrogen (NOx) are the major emittants of concern coming from commercial aircraft engines. Current state-of-the-art engines and combustors in most subsonic aircraft are fuel efficient and meet the 1996 ICAO nitrogen oxide(NOx) limits. Recent observations of aircraft exhaust contrails (from both subsonic and supersonic flights) have resulted in growing concern over aerosol, particulate, and sulfur levels in the fuel. In particular, aerosols and particulates from aircraft are suspected of producing high altitude clouds which could adversely affect the earth's climatology. Advanced concepts research for reducing CO₂ and NOx, and analytical and experimental research in characterization (intrusive and non-intrusive) and control (through component design, controls, and/or fuel additives) of gaseous, liquid and particulates of aircraft exhaust emissions is sought. Specific aircraft operating conditions of interest include the landing-takeoff cycle as well as the in-flight portion of the mission. Areas of particular interest include:

• New concepts for reducing CO₂, oxides of nitrogen (NO, NO₂, NOx), unburned hydrocarbons; carbon monoxide, particulate, and aerosols emittants (novel propulsion concepts, injector designs to improve fuel mixing, catalysts, additives, etc.)
• New fuels for commercial aircraft which minimize CO₂ and NOx emissions
• Innovative active control concepts for emission minimization with an integrated systems focus including emission modeling for control, sensing and actuation requirements, control logic development, and experimental validation are of interest
• New instrumentation techniques are needed for the measurement of engine emissions such as NOx, SOx, HOx, atomic oxygen and hydrocarbons in combustion facilities and engines. Size, size distributions, reactivity, and constituents of aerosols and particulates are needed, as are temperature, pressure, density, and velocity measurements. Optical techniques that provide 2D and 3D data; time history measurements; and thin film, fiber optic, and MEMS-based sensors are of interest.

Noise: Engine noise reduction technologies are required in the areas of propulsion source noise, nacelle aeroacoustics, and engine/airframe integration. Some of the key technologies needed to achieve these goals are revolutionary propulsion systems for reduced noise without significant increases in cost and emissions. Noise reduction concepts need to be identified that provide economical alternatives to conventional propulsion systems. NASA is soliciting proposals in one or more of the following areas for propulsion system noise reduction:

• Innovative acoustic source identification techniques for turbomachinery noise: The technique shall be described for a relevant source. Plans for a Phase II demonstration should be included for the Phase I proposal. A simple source may be used where the solution is known to demonstrate the technique. A clear explanation on how the technique can be applied to turbofan engines should be included. The technique should be capable of identifying sources contributing to dominant engine components, such as fan and jet noise.
• Fan Noise: The technique shall be capable of separating fan sources such as fan-alone versus fan/stator interaction for both tones and broadband noise. Sufficient resolution is needed to determine the location of the dominant sources on the aerodynamic surfaces. Jet Noise: The technique shall be capable of locating both internal and external mixing noise for dual-flow nozzles found in modern turbofans.
• Innovative turbofan source reduction techniques. Methods shall emphasize noise reduction methods for fan, jet and core components without compromising performance for turbofan engines. A resulting engine system that incorporates one or more of the proposed methods should be capable of reducing perceived noise levels anywhere from 10 to 20 EPNdB relative to FAR 36, Stage 3 certification levels.
• Revolutionary propulsion concepts for lower emissions and noise (proposed as alternatives to turbofan engines). Feasibility studies shall be done that demonstrate the potential for 20 EPNdB engine noise reduction relative to FAR 36, Stage 3 certification levels and 90% reduction in NOx emissions standards relative to current ICAO regulations for commercial aircraft concepts. Enabling technologies shall be identified for future research.

Advanced Materials for Reduced Emissions: Proposals are also sought to address advanced materials, their development, and their application to primary propulsion systems such as aircraft gas turbines, rocket and turbine based combined cycle engines, as well as auxiliary power sources in aircraft and space vehicles. Materials of interest include any especially used in propulsion systems such as high temperature polymers, nickel base alloys, ceramic matrix composites, coatings for these, and processes for their economical and reliable preparation.

A2.02 Electric and Intelligent Propulsion Technologies for Environmentally Harmonious Aircraft
Lead Center: GRC

With the increased emphasis on safety, enhanced performance and affordability, and the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aerospace propulsion systems.

Electric aircraft propulsion & power systems have the potential to completely eliminate harmful emissions from aircraft while at the same time doubling fuel efficiency. Major strides have been achieved in the development of electrical systems and components especially in the automotive field. We now appear to be on the threshold of viable electric flight. There are still major technical advances required to make commercially viable electric aircraft a reality, but the goal does now appear to be achievable, possibly even in the nearer term for smaller family sized air vehicles. To achieve the implementation of environmentally harmonious twenty-first century air vehicles, innovations are needed to enable highly efficient, low cost, power dense (weight and volume) electric aircraft propulsions & power systems.

Intelligent propulsion technologies have the potential to enable the design of extremely safe, high performance propulsion systems that will also meet the stringent affordability and environmental requirements of the future. For turbomachinery based propulsion systems, the approach has been to design engine components such as combustors, fans and compressors, inlets, nozzles, etc., for optimum component performance within some overall system constraints and the control problem was to transition the operating point of the engine from one set point to another in the most expedient manner without compromising safety. With the advancements in information technologies and various disciplines relevant to aeropropulsion, the component designers are beginning to realize the potential of "Intelligent Engines" in helping them meet more stringent design requirements.

Implementation of intelligent propulsion concepts requires advancements in the area of robust control synthesis techniques and automated diagnostics, and development of advanced enabling technologies such as smart sensors and actuators. Attention will also need to be paid to integration of the active component control and diagnostics technologies with the control of the overall propulsion system. This will require moving from the current analog control systems to distributed control architectures.

Technical areas of interest in electric aircraft propulsion and power include, but are not limited to, fuel cells, power management, power conditioning, power distribution, actuators, motor drive systems, fuel storage (especially hydrogen). Highly integrated dual function components and systems that have the potential to reduce overall weight are of special interest (e.g., power conductors that are integrated into the airframe structure, motors directly integrated into the fan/propeller structure, etc.) Both component and system level technologies are solicited.

Intelligent propulsion technologies that address electric, turbine, jet and/or hybrid aerospace propulsion systems are of interest. Proposals focusing on development of advanced diagnostics, health monitoring and control concepts, and smart sensors, electronics and actuators for enabling self-diagnostic and prognostic, and self-reconfiguration capabilities being sought. Concepts integrating distributed sensing and, actuation and control logic for micro level control of parameters, such as propulsion system internal flows, that impact performance and environment are of special interest. Novel instrumentation approaches that provide valuable information for development and validation of technologies for self-diagnosis, prognosis and reconfiguration are also of interest.

NASA seeks highly innovative concepts for propulsion systems and components for advanced high speed aerospace vehicles, to support missions, such as access to space, global cruise, and high-speed transports. The main emphasis in this subtopic is on high-risk, breakthrough technologies in order to revolutionize present-day gas turbine engines to operate over a flight spectrum of up to Mach 8. Specific technical areas include the following:

• Advanced cooling concepts that minimize coolant penalties. This can include innovative cooling systems, materials concepts, fuel cooling of combustor, and endothermic fuels and/or fuel additives to increase the heat-sink capacity or cooling capacity of fuels.
• Innovative concepts relating to combustion process, including fuel injectors, piloting, flame holding techniques for increased performance and decreased emissions, techniques to identify the onset of combustion instability in lean-burn and/or rich-burn, low NOx combustor, ramjet combustion and active and passive combustion controls in order to extend the operability of the combustion components to a wider range of operating conditions.
• New inlet concepts to meet functional airflow needs of high Mach number propulsion. For instance, a variable geometry, supersonic, mixed compression inlet. Compatibility with turbomachinery and mode transition across the speed range should be addressed. Special attention should be given to combustor demands along a realistic flight corridor. This flight corridor must be compatible with turbine engine thermal-structure limits.
• New techniques to improve the aerodynamic performance and operability of the inlet, including highly offset subsonic diffusers and designs for boundary layer control, minimizing engine unstart susceptibility, and techniques to identify and control the onset of mode transition between different propulsion concepts within the same internal flowpath or dual flowpaths.
• New controllable and reliable nozzle concepts with optimum expansion efficiency and thrust vectoring capability, including a computational nozzle design methodology to study various geometries and chemistry effects.
• Enabling technologies of components and subsystems that allow turbomachinery to operate at high-speed flight conditions. Specific examples include 1) a lightweight, high pressure ratio com-pressor which must be protected or removed from the extremely high temperature primary air stream; 2) applications of advanced ceramic/composite materials or micro-electrical-mechanical systems that demonstrate the potential to enhance the performance and reduce the cost and weight; and 3) innovative inlet flow conditioning.
• New concepts for combined/combination cycles, in particular those including turbine propulsion. Alternate engine cycles that meet a unique mission requirement (e.g. global reach, access to space, etc.), including pulse detonation, ramjets, scramjets, and rockets. Proposals can also include de-velopment of unique components required for the maturation of alternate propulsion cycles, such as inlets, diffusers, nozzles, air-valves, fuel injectors, combustors, etc.

Innovative technologies and methods are necessary for the design and development of efficient, environ-mentally acceptable airplanes, rotorcraft and advanced aerospace vehicles. Improvements in noise prediction and control are needed for jet, propeller, rotor, fan, turbomachinery, and airframe noise sources to reduce the impact on community residents, aircraft passengers and crew, and launch vehicle payloads. Innovations in the following specific areas are solicited:

• Fundamental and applied computational fluid-dynamics techniques for aeroacoustic analysis, par-ticularly for use early in the design process.
• Simulation and prediction of aeroacoustic noise sources particularly for airframe noise sources and situations with significant interactions between airframe and propulsion systems.
• Innovative active and passive acoustic treatment concepts for engine nacelle liners.
• Concepts for active and passive control of aeroacoustic noise sources for advanced aircraft configurations.
• Reduction technologies and prediction methods for rotorcraft and advanced propeller aerodynamic noise.
• Computational and analytical structural acoustics techniques for aircraft and advanced aerospace vehicle interior noise prediction, particularly for use early in the airframe design process.
• Technologies and techniques for active and passive interior noise control for aircraft and advanced aerospace vehicle structures.
• Prediction and control of high-amplitude aeroacoustic loads on advanced aerospace structures and the resulting dynamic response and fatigue.
• Development and application of flight procedures for reducing community noise impact of rotor-craft and future subsonic and supersonic commercial aircraft while maintaining safety, capacity and fuel efficiency.
• Development of synthesis and auditory display technologies for subjective assessments of interior and exterior aircraft noise.

[back to top]

[back to top] [ back to Solicitation ] [ back to Chapter 9.1.1 ] [ back to Chapter 9.1 ] [ back to Chapter 9 ] [ back to table of contents ]