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Technical Paper

Electromagnetic Characteristic Comparison of Superconducting Synchronous Motors for Electric Aircraft Propulsion Systems

Aircraft service has been increasing today and it also results in the increase of the greenhouse gas emission. To solve this problem, the electric aircraft propulsion system is the key solutions to realize the clean and high efficiency aircraft, while demanding higher output density motors. So far, though 5 kW/kg is realized with permanent magnet type synchronous motors, the electric aircraft for over 100 passengers demands motors with 16 -20 kW/kg. Superconducting (S.C.) technology is one of the effective candidates for higher output density motors. In comparison with copper wires, the S.C. wires have higher current density at less than –200 ℃. And we can make a lighter weight coil with the S.C. wires. So far, many groups have been studying the S.C. motors over 16 kW/kg. Generally, there are two kinds of S.C motors. One is the S.C. motors made of the S.C. field coils and copper armature windings. The other is the fully S.C. motors using S.C. field and armature windings.

Filter Element Cleaning Methods

This SAE Aerospace Information Report (AIR) provides technical information to assist the development of specific cleaning methods for filter elements. Consideration is limited to filter elements which are designated as "cleanable" (not "disposable"), but which cannot be cleaned by simple and obvious procedures. Cleaning methods developed according to this report should be evaluated by the methods of ARP725. Satisfactory cleaning methods can be developed for most "cleanable" filter elements. Technical or economic feasibility of the cleaning method may be limited, however, by incompatibility of filter-element construction materials, by mechanical weakness or lack of corrosion resistance to withstand repeated or continued cleaning, or by the presence of unusually tenacious contamination. These factors must be considered when selecting approaches to the development of specific methods.
Technical Paper

Testing of Elastomer Icephobic Coatings in the AIWT: Lessons Learned

A study has been conducted into icephobic properties of some highly durable “off-the-shelf” elastomer materials using a rotating ice adhesion test rig installed in the NRC’s Altitude Icing Wind Tunnel. This enabled the formation of ice at environmental conditions similar to those experienced during in-flight icing encounters. Initially, the tests indicated some very positive results with ice adhesion shear stress as low as 8KPa. On further examination, however, it became apparent that the test preparation process, in which the samples were cleaned with an ethanol alcohol solution, influenced the results due to absorption and prolonged retention of the cleaning fluid. The uptake of the ethanol alcohol solution by the elastomer was found to be a function of the surface temperature and remained absorbed into the coating during the ice accretion process changing the characteristics of the coating in such a way that led to a reduction in the ice/surface bond strength.

Boeing reports on its environmental efforts

The strategy identifies 2025 as a target year to collaborate with communities around the globe and create products focused on environmental performance, emissions and waste reduction, and lower levels of water and energy consumption at work sites.

Flux, Aluminum Welding

This specification covers an aluminum welding flux in the form of powder.

United ups commitment to sustainable aviation biofuel, extends contract with World Energy

United Airlines officials in Chicago have strengthened their commitment to ensuring United is an environmentally conscious carrier by expanding its contract with Boston-based World Energy and agreeing to purchase up to 10 million gallons of commercial-scale, sustainable aviation biofuel over the next two years. United currently uses the biofuel to help sustainably power every flight departing out of its Los Angeles Airport (LAX) hub and achieve more than a 60 percent reduction in greenhouse gas emissions on a lifecycle basis, officials say.

Thermodynamics of Incompressible and Compressible Fluid Flow

The fluid flow treated in this section is isothermal, subsonic, and incompressible. The effects of heat addition, work on the fluid, variation in sonic velocity, and changes in elevation are neglected. An incompressible fluid is one in which a change in pressure causes no resulting change in fluid density. The assumption that liquids are incompressible introduces no appreciable error in calculations, but the assumption that a gas is incompressible introduces an error of a magnitude that is dependent on the fluid velocity and on the loss coefficient of the particular duct section or piece of equipment. Fig. 1A-1 shows the error in pressure drop resulting from assuming that air is incompressible. With reasonably small loss coefficients and the accuracy that is usually required in most calculations, compressible fluids may be treated as incompressible for velocities less than Mach 0.2.
Technical Paper

Energy, Exergy and Emission Performance Analysis of Air-Film Blade Cooled Turbo Prop Turbine for Heavy Duty Cargo Aircrafts

In the present scenario, when the non-conventional energy resources are still under development stage for their full potential as a source of energy for our fast growing population, gas turbines are one of the most promising power generation technologies. The gas turbine based power utilities are also gaining acceptance across globe, because of increase in extraction of natural gas. Further reduction in the price of natural gas would also result in the number of gas turbine units installed across globe and thus it is important to carry out the environmental analysis of gas turbine based utilities. The gas turbines are employed in power generation in industries, aircrafts and marine propulsion units. The present exercise carries out thermodynamic performance analysis i.e. energy, exergy and emission performance analysis of an air-craft gas turbine. The gas turbine blades of present cycle are assumed to be cooled by air-film blade cooling technique.

Orbex debuts innovative smallsat launch vehicle

Orbex, a developer of small satellite (smallsat) launch vehicles based in Forres, Scotland, has unveiled its “Prime” launch vehicle. The rocket utilizes several novel technologies, including the world’s largest metal rocket engine produced as a single piece through additive manufacturing (AM).

Test Method for Aerospace Firewall Sealant Flame Penetration

This SAE Aerospace Standard (AS) describes the procedures for the flammability testing of aircraft firewall sealants in accordance with the requirements of FAR Part 25 Sections 25.865, 25.867, 25.1191, and 25.1193. This test method is intended to determine the capability of sealant materials to control the passage of and effects from fire.

Aerospace Standard Test Methods for Aerospace Sealants Two-Component Synthetic Rubber Compounds

This SAE Aerospace Standard (AS) describes test methods to determine the application and performance properties of two-component sealing compounds. It shall be used in conjunction with AS5127 and the applicable material specification. When modifications to these test methods are called out in material specifications, the material specification shall take precedence.

New four-chamber rotary engine could supplant Wankel and piston engines for UAV applications

A new configuration of a rotary engine – the Szorenyi rotary engine – has been developed by the Melbourne-based Rotary Engine Development Agency (REDA). While the stator, or stationary part of the Szorenyi engine is similar to that of a Wankel engine, the geometric shape of the engine rotor is a rhombus, which deforms as it rotates inside the contour of the stator.

Etch Inspection of High Strength Steel Parts

This specification establishes the requirements for etch inspection of bare high strength low alloy steel parts having tensile strength of 180 ksi (1241 MPa) and higher and of carburized parts to detect overheating caused by abusive machining or grinding in the heat treated condition, and to detect localized discontinuous carburization. This process is not applicable to surface hardened steels produced by nitriding or carbonitriding. This process may remove 0.0001 to 0.0005 inch (2.5 to 12.7 micrometers) from the surface of the part.