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An innovative rotary engine uses a rotor that executes pendulum-like oscillatory rotation. This is converted into uniform rotation of the drive shaft by a simple mechanism. The new design is compact, lightweight and powerful. Simpler and cheaper fabrication, lower levels of noise and vibration, easier maintenance are among its advantages over the Wankel rotary engine and the Otto piston engine.

The need for Air Turbine Starter (ATS) condition monitoring is driven by industry demand for continuous improvement in reliability and reduction in repair and overhaul costs. This paper discusses issues for condition monitoring of Air Turbine Starters (ATS), including the need for condition monitoring, selection of monitoring parameters, current projects, and goals for future designs. The USAF is currently conducting a program to develop a simple, stand-alone device capable of indicating impending failures. This device will likely focus on a combination of temperature monitoring and magnetic chip detection. Future ATS condition monitoring devices should be capable of more comprehensive evaluation of starter parameters.

Global market forces are driving down the cost-of-ownership requirements of future passenger aircraft from today's already competitive levels. All elements of the aircraft, including the Auxiliary Power Unit (APU), will have to contribute by providing superior performance and reliability within an environment which will demand even greater product value. This challenge will be met with well proven design pedigree and an appropriate balance of new technology and systems integration. APIC, a Sundstrand Aerospace Company, is addressing these market demands by continually improving the operational and economic performance of its current APU products while developing the design, manufacturing and integration technologies that will offer even higher value for future aircraft platforms. This paper provides a status of current APU technology and describes how successful integration with the aircraft and its systems has been used to add value and reduce development cycle time.

A noncontacting clearance seal consists of a series of centrifugal air pumps and oil/air separators for air turbine starters on the BR710 and the CFM56-5 engines. Conventional contacting seals for rotating shafts are limited in life due to the formation of oxidized oil coke buildup on the sealing surfaces. The clearance seal directly addresses the problem of viscous heat generation in carbon face and lip seals by eliminating contact. Standard contacting seals typically have local temperature increases of 50 to 75 °F higher than the gearbox sump oil. Heat generation by the clearance seal is minimized, resulting in a significant increase in reliability compared to a standard contacting seal. The reliability increase is estimated for various flight-hour-to-start-cycle ratios in air turbine starter gearboxes.

Developing unmanned aerial vehicles (UAVs) with an electric propulsion system that combines photovoltaic modules with an energy storage system has been an ongoing goal of the aeronautics community. A closed-loop energy storage system using a fuel cell and electrolyzer will enable the UAV to operate at high altitudes (> 20 km) and for mission durations over a year. However, the specific energy of the energy storage system must be increased beyond present 150W-hr/kg levels. A high capacity fuel cell and electrolyzer unit under development at Physical Sciences Inc. (PSI) is aiming to improve the energy storage capability to values much greater than 500 W-hr/kg.

This manuscript addresses the characterization and evaluation of various nickel hydroxide half cells designed for use in aircraft batteries. Four different electrode configurations are examined for performance. Characterization testing includes evaluation for cycle life, utilization, capacity at temperature, and capacity at current.

Unmanned Aerial Vehicles (UAV) are being proposed for many applications including surveillance, mapping and atmospheric studies. These applications require a lightweight, low speed, medium to long duration aircraft. Due to the weight, speed, and altitude constraints imposed on such an aircraft, solar array generated electric power can be a viable alternative to air-breathing engines for certain missions. Development of such an aircraft is currently being funded under the Environmental Research Aircraft and Sensor Technology (ERAST) program. NASA Lewis Research Center (LeRC) has built a Solar Electric Airplane to demonstrate UAV technology. This aircraft utilizes high efficiency Applied Solar Energy Corporation (ASEC) GaAs/Ge space solar cells. The cells have been provided by the Air Force through the ManTech Office.

The Nickel Metal Hydride Battery system has emerged as the battery of choice for portable computers, cell phones and other small electronic applications. It also is a leading candidate to serve as the energy storage source for electric and hybrid electric vehicles. The Nickel Metal Hydride battery eliminates the use of highly toxic chemicals which is a major consideration for environmental issues. The battery also exhibits higher energy density than Lead-Acid and Nickel-Cadmium batteries along with excellent power capabilities. These features make this battery a viable candidate for aircraft applications and that is the subject of this presentation.

This paper explores an approach, based on the Analytical Hierarchy Process, that provides a logical, quantitative means to identify the best battery types to employ in each of the following categories of aircraft: fighter, bomber, and cargo/transport. Three battery types are considered: vented nickel-cadmium (VNC), ultra-low maintenance (vented) nickel-cadmium (ULMNC), and sealed lead-acid (SLA). The analysis ranks the three battery types for suitability of use on each aircraft type based on eleven selection criteria: Current Output, Energy Density, Power Density, Reliability, Ruggedness, Initial Cost, Life-Cycle Cost, Maintainability, Useful Life, Hazard Level, and Experience. (The rankings are based on the judgement of the author drawing from opinions of experts and published technical sources). The selection criteria are weighted according to their relative importance for each of three aircraft types.

Historically, Transformer Rectifiers Units (TRUs) have been unregulated devices used to provide 28-Volt Direct Current (vdc) power on 400 Hertz, 115-Volt Alternating Current (vac) aircraft. By design, a TRU produces an unregulated voltage output that varies with current (load) required by utilization equipment on the 28-Volt Buss. This TRU voltage output variation typically ranges from 30-31 volts (at no load) down to 24 volts (at 100%load) under stable input conditions. AC transients, in combination with sudden or heavy DC loads, can cause a typical TRU voltage output to fall into the 17-18 volt range or even lower. Modern aircraft are experiencing three trends which are impacted by older TRU characteristics. The first is that airframes are being used for longer periods of time; scheduled use is being increased to avoid the budget constraints of replacing costly airframes.

Prototype miniature heat pipes have been fabricated that are compatible with high and low temperature ceramic multichip module (MCM-C) processing. The heat pipe is fabricated as an integral part of the MCM-C substrate using conventional numerically controlled machining operations. The heat pipe uses an axially grooved wick structure to provide transport of the working fluid from the condenser to the evaporator. The working fluid chosen for the heat pipe was water. Preliminary testing was performed using the heat pipe as a thermal spreader to enhance cooling by convection and for axial transport of heat to the edge of the substrate for cooling by conduction. Up to 16 Watts of heat were transported by the heat pipe with cooling provided along the condenser region by natural convection or by a temperature controlled cooling jacket. In all cases, the temperature variation along the length of the substrate surface was less than 5°C.

A battery-charger-controller system comprising a 28V nickel-cadmium battery and a 270 Vdc -powered charger-controller unit is described.

VGCF/Carbon composites have been shown to demonstrate high thermal conductivity, comparable to that of CVD diamond, implying utility in high performance electronic packaging. VGCF/carbon composites are unlike diamond in that, typical of most fiber reinforced composites, designed physical properties are incorporated into the composite through fiber architecture. Thermal performance for die cooling is frequently determined by the thermal impedance of the package, measured from the junction to ambient, ϕja, or jucntion to case, ϕjc. This paper reports the results of this test on VGCF/carbon composites with a 1D architecture.

Rotating Heat Pipe (RHP) technolog y is being developed for high speed (>20 krpm) regimes of electric motor/generator cooling. The motivation for this research is the potential application of the high speed RHPs for the thermal management of advanced rotating electrical machines. The passive nature and relatively simple features of this device are attractive for the removal of waste heat from the rotors of electric machines. Interesting air-cooling experimental results of two high speed RHPs designed, fabricated and tested at AFRL are presented here. Emphasis is made on external heat removal concepts useful for cooling the RHP condenser in order to be successful in promoting this technology to real world problems.

Metal matrix composites (MMCs) reinforced with vapor-grown carbon fiber (VGCF) may offer thermal conductivity superior to materials currently used for thermal management while also providing an adjustable coefficient of thermal expansion (CTE) and low density. Extrapolating from results on aluminum MMC with lower loadings of VGCF suggest that aluminum and copper MMCs can attain a best-direction conductivity in excess of 1000 W/m-K. Alternatively, isotropic in-plane conductivity may reach up to 800 W/m-K, while matching the CTE of important semiconducting materials.

High-density electronics packaging requires new advancement in thermal management. New efforts to standardize three-dimensional electronics packages provide the opportunity to standardize thermal management systems for the first time. Microchannel cooling, a high heat flux technology, is the leading candidate for standardization of earth- and space- based electronics packages. This paper looks at the developments in microchannel cooling that make it more advantageous than other high heat flux techniques and the work that remains to achieve a standardized thermal management system.

This paper will describe a patent-pending approach of using a vapor compression system to also provide a forced two-phase indirect heat transfer loop. This system can be configured with water boiler peak cooling thermal control hardware to avoid the high ambient temperatures associated with supersonic low altitude flight. Due to the very short duration of this high ambient condition, water boiler transient cooling techniques have potential. The water boiler can also be used for ground based cooling when flight-line ground cooling carts are unavailable. The use of a PID controller to accurately control the cold plate temperatures when used with a solenoid activated by-pass circuit will be described.

Recently, aerodynamic noise which originates in the flow of the body surroundings is actualized as a main cause of an automobile interior noise when running at high speed, because engine, power train and tire noise have been greatly decreased. Along with it, the measurement technology for the phenomenon elucidation and the evaluation has been demanded to decrease aerodynamic noise. In this paper, typical measurement examples of aerodynamic noise are introduced. These measurement technologies can be classified, and arranged to four types of measurements, which are flow, external noise, transmission psth and interior noise. This paper presents how the advancement of these measurement technologies has contributed to the aerodynamic noise elucidation. Moreover, the latest evaluation method of aerodynamic noise and the trend in the future to the demand of customer's many topics are introduced.

In the search for clean and efficient power, PEM fuel cells have been identified as the technology that can meet our future needs for transport applications. Hydrogen-powered PEM fuel cell vehicles are perceived to give the ultimate advantage, but the complications involved with hydrogen storage and refuelling, as well as the lack of infrastructure call for a different solution. In the near term, this is almost certain to be the on-board generation of hydrogen from a readily available fuel. At Johnson Matthey, a novel modular reformer (HotSpot™) has been developed for methanol, and has been demonstrated to have many of the qualities that are required for automotive applications. Auxiliary technologies for CO removal (Demonox) and aftertreatment have also been developed, and integrated with the reformer to form 20 kWe processor, which is currently undergoing brass-board testing.

The 100-year saga of The Timken Company is a testament to the enduring power of innovation, grit and periodic self-renewal. It is the story of a quest to solve one of industry's oldest, most limiting and expensive challenges: friction. Today's Timken combines materials science with bearing technology to produce products that range from a half ounce to nine tons and help power and control applications that span disk drives, drilling rigs, dental drills and rolling mills. Today's automotive bearing is less than half the size and 90 percent lighter than its ancestor - and carries twice the load.