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Technical Paper

Aerodynamic Analysis of a Passenger Car to Reduce Drag using Active Grill Shutters and Active Air Dams

2019-11-21
2019-28-2408
Active aerodynamics can be defined as the concept of reducing drag by making real-time changes to certain devices such that it modifies the airflow around a vehicle. Using such devices also have the added advantages of improving ergonomics and performance along with aesthetics. A significant reduction in fuel consumption can also be seen when using such devices. The objective of this work is to reduce drag acting on a passenger car using the concept of active aerodynamics with grill shutters and air dams. First, analysis has been carried out on a baseline passenger car and further simulated using active grill shutters and air dams for vehicle speed ranging from 60 kmph to 120 kmph, with each active device open from 0° to 90°. The improved model obtained is then subjected to variations in yaw angle ranging from -18° to +18°. The optimized model is then validated for a scaled down prototype in a wind tunnel.
Technical Paper

Optimization of CI Engine Performance and Emissions Fueled by Blends of Alternative Fuels Methyl Ester Using Taguchi and Multi Regression Analysis

2019-09-16
2019-01-1893
Today’s frenetic engine manufacturing and transportation sector and its related traces viz; noise and vibration of our modern societies has adverse effect on environment as well as all of us. Modern research affords us the opportunity to understand the subject better and to develop advance technologies. Widely immediate slogan and goal of all industries might be to improve the performance and reduce emission using alternative fuel while, make the quietest and smoothest running Engines. To, reduce the dependency on diesel fuel (Due to rapid worldwide depletion) Biodiesel is one of the immediate, alternative and complimentary solution. In the Present study, to optimize the operating parameters of the Direct Injection Single Cylinder (5.2 kw) CI engine with respect to Brake Thermal Efficiency (BTE), Carbon monoxide (CO), Oxides of Nitrogen, Hydrocarbons (HC) etc..
Technical Paper

Gradationally Controlled Voltage Inverter for More Electric Aircrafts

2019-09-16
2019-01-1913
Over recent decades, there has been a lot of progress toward a more electric aircraft (MEA) to reduce emissions and fuel consumption. In MEAs, many subsystems that previously used hydraulic or pneumatic power have been replaced by electrical systems with inverters and electrical machines. Therefore, MEAs reduce the weight, i.e. fuel consumption, and maintenance cost. To achieve advanced electrical systems, the weight of inverters has significant importance. In this work, a gradationally controlled voltage (GCV) inverter is proposed to reduce the weight and enhance reliability. A GCV inverter can supply gradational quasi-sinusoidal voltages combining two different voltages from a 3-phase 3-level (main) inverter and three single-phase H-bridge (sub) inverters. A dc power supply is required only for the main inverter. A main inverter with Si-IGBTs supplies the fundamental voltage by only one switching in the fundamental period.
Technical Paper

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

2019-09-16
2019-01-1912
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.
Technical Paper

Flight Optimization Model on Global and Interval Ranges for Conceptual Studies of MEA Systems

2019-09-16
2019-01-1906
In development of more electric aircraft applications, it is important to discuss aircraft energy management on various level of aircraft operation. This paper presents a computationally efficient optimization model for evaluating flight efficiency on global and interval flight ranges. The model is described as an optimal control problem with an objective functional subjected to state condition and control input constraints along a flight path range. A flight model consists of aircraft point-mass equations of motion including engine and aerodynamic models. The engine model generates the engine thrust and fuel consumption rate for operation condition and the aerodynamic model generates the drag force and lift force of an aircraft for flight conditions. These models is identified by data taken from a published literature as an example. First, approximate optimization process is performed for climb, cruise, decent and approach as each interval range path.
Technical Paper

Preliminary Design of Hydraulic and Pneumatic System Architectures for a Morphing Flight Control Structure

2019-09-16
2019-01-1916
Bionics in aeronautics has the potential to increase the performance and efficiency of aircraft significantly. Inspired by the wings of birds, morphing wing structures are extensively investigated over the last decades. The continuous adaption of the wings over a large scale of the flight envelope enables an optimization of the aerodynamic characteristics and, in this way, a reduction of the fuel consumption. Additionally, those structures could support or replace traditional flight control surfaces. Depending on the morphing technology, different systems may be suitable to actuate the morphing structure. An early inclusion of the system architecture concepts into the development of the morphing technology enables the design of an optimal system in compliance with all requirements. Therefore, this paper discusses the conceptual design of system architectures for a novel morphing wing structure that is used for flight control.
Standard

Filter Element Cleaning Methods

2019-07-15
WIP
AIR787B
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.
Standard

Wire, Electrical, Crosslinked Polyalkene, Crosslinked Alkane-Imide Polymer, Or Polyarlyene Insulated, Copper Or Copper Alloy

2019-07-08
CURRENT
AS81044B
AS81044 covers single conductor electric wires made as specified in the applicable detail specification with tin-coated, silver-coated, or nickel-coated copper or copper alloy conductors insulated with crosslinked polyalkene, crosslinked alkane imide polymer, or polyarylene. The crosslinked polyalkene, crosslinked alkane-imide polymer, or polyarylene may be used alone or in combination with other insulation materials as specified in the detail specification.
Standard

Magnesium Alloys in Aircraft Seats - Developments in Magnesium Alloy Flammability Testing

2019-06-19
WIP
AIR6160A
This document provides informational background, rationale and a technical case to allow consideration of the removal of the magnesium alloy restriction in aircraft seat construction as contained in AS8049B. The foundation of this argument is flammability characterization work performed by the FAA at the William J. Hughes Technical Center (FAATC), Fire Safety Branch in Atlantic City, New Jersey, USA. The rationale and detailed testing results are presented along with flammability reports that have concluded that the use of specific types of magnesium alloys in aircraft seat construction does not increase the hazard level potential in the passenger cabin in a post-crash fire scenario. Further, the FAA has developed a lab scale test method, reference DOT/FAA/TC-13/52, to be used as a certification test, or method of compliance (MOC) to allow acceptability of the use of magnesium in the governing TSO-C127 and TSO-C39C.
Standard

Polyamide Type 6-6, Plastic Moldings and Extrusions

2019-06-13
CURRENT
AMS3617F
This specification covers one type of nylon thermoplastic resin in the form of moldings and extrusions. These products have been used typically for parts requiring high strength and resistance to aircraft fuels and lubricants up to 120 degrees C (248 degrees F), but usage is not limited to such applications.
Technical Paper

Testing of Elastomer Icephobic Coatings in the AIWT: Lessons Learned

2019-06-10
2019-01-1994
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.
Article

Boeing reports on its environmental efforts

2019-06-05
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.
Standard

Flux, Aluminum Welding

2019-06-03
WIP
AMS3414F
This specification covers an aluminum welding flux in the form of powder.
Article

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

2019-05-23
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.
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