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Technical Paper

Design Analysis of High Power Density Additively Manufactured Induction Motor

2016-09-20
2016-01-2061
Induction machines (IM) are considered work horse for industrial applications due to their rugged, reliable and inexpensive nature; however, their low power density restricts their use in volume and weight limited environments such as an aerospace, traction and propulsion applications. Given recent advancements in additive manufacturing technologies, this paper presents opportunity to improve power density of induction machines by taking advantage of higher slot fill factor (SFF) (defined as ratio of bare copper area to slot area) is explored. Increase in SFF is achieved by deposition of copper in much more compact way than conventional manufacturing methods of winding in electrical machines. Thus a design tradeoff study for an induction motor with improved SFF is essential to identify and highlight the potentials of IM for high power density applications and is elaborated in this paper.
Journal Article

Cast Body Nodes for 2016 Acura NSX

2015-04-14
2015-01-0512
Ablation casting is an emerging technology which combines traditional sand molding techniques with rapid cooling due to the use of a water soluble binder. High cooling rates and control of solidification direction allows for exceptional mechanical properties and complex shapes. Through the use of ablation, six different body node castings have been manufactured for the 2016 NSX aluminum space frame. The high mechanical properties allowed these castings to be integrated into the crash structure for energy absorption. Using the traditional casting alloy A356, target mechanical properties were 190 Mpa Yield Strength, 280 Mpa Tensile Strength and 12% min elongation. The high elongation was achieved due to the refined eutectic microstructure produced by high cooling rates. The eutectic microstructure produced by ablation was found to be Level 5 or 6 on the AFS scale. Light weighting could also be achieved when compared to traditional GDC castings.
Technical Paper

Development of Robust Anti-chipping Performance Primer for Various Application Process Conditions

2016-04-05
2016-01-0534
Chipping performance of body paint on a vehicle has become increasingly important in harsher climates such as North America and Russia. Stones can cause body paint to chip down to substrate and expose bare metal, which can then lead to corrosion. The primer layer serves not only as the adhesion promoter between metal substrate and topcoat, but also secures overall chipping performance of the coating system. The benefits of a softer body primer have been established and described in Bock and Engbert’s SAE paper “Waterborne Polyurethane Based Paint Materials for the Automotive Industry - Present Situation and Future Possibilities - ,”[1], however, the challenge exists in accommodating various application process conditions.
Technical Paper

Thermal Approach to the Flexible External Insulation of the Hermes Spaceplane

1989-07-01
891493
The flexible external insulation is part of the HERMES thermal protection system. It is designed to cover the central and upper fuselage and upper wing sections. In the central fuselage area, extreme temperatures up to 800°C can be expected. The FEI configuration chosen is described with respect to thermal properties. The thermal development of the FEI is performed in iterative steps of analytical evaluations, experimental investigations and adaptation/improvement of the analytical approach to the test results. During the pre-development work, a two-dimensional thermal mathematical SINDA model of the FEI has been established with separate functions describing radiative, gas and solid heat exchange. The results of transient analyses with respect to external heat loads during re-entry are presented. Calorimetric tests have been performed measuring the heat transfer fractions separately. Test and analysis results are in good agreement.
Technical Paper

Potential for Reduction of Decompression Sickness By Prebreathing With 100% Oxygen While Exercising

1989-07-01
891490
Exercise performed for at least 30 min while prebreathing 100% oxygen prior to decompression has been reported to increase efficiency of denitrogenation by 100-500%. The incidence of decompression sickness following such a prebreathe was decreased by 50% compared to resting prebreathe. If prebreathing with exercise is to have an operational application, it must be brief, it must significantly reduce standard prebreathing times, it must not create excess fatigue, and it must use exercise equipment compatible with aerospace operations. This article provides background and recommends parameters for a test to determine the operational feasibility of prebreathing with exercise.
Technical Paper

Mouse Tall-Suspension as a Model of Microgravity: Effects on Skeletal, Neural and Muscular Systems

1989-07-01
891489
Tail-suspension of rats has been shown to cause loss of bone mass similar to that experienced by humans in microgravity. We have applied tail-suspension to mice to characterize bone, nervous system and muscle changes that occur and evaluate the use of magnetic fields to obviate these changes. Results have shown that femurs and tibiae of tail-suspended mice undergo significant decreases in dry weight, stiffness and strength. Immersion of mice in specific oscillating magnetic fields can reduce or eliminate these degenerative changes. Results have also shown that tail-suspended animals undergo changes in spinal cord function similar to changes previously observed in animals with damaged sciatic nerves. These changes include decreases in the uptake of GABA (an inhibitory neurotransmitter) into a purified fraction of synaptic nerve endings and changes in electrical responses recorded in an isolated spinal cord preparation.
Technical Paper

A Human Factors Evaluation of Extravehicular Activity Gloves

1989-07-01
891472
One of the major problems faced in Extravehicular Activity (EVA) glove development has been the absence of concise and reliable methods to measure the effects of EVA gloves on human-hand capabilities. NASA has sponsored a program to develop a standardized set of tests designed to assess EVA-gloved hand capabilities in six performance domains: Range of Motion. Strength, Tactile Perception, Dexterity, Fatigue, and Comfort, Based upon an assessment of general human-hand functioning and EVA task requirements, several tests within each performance domain were developed to provide a comprehensive evaluation. All tests were designed to be conducted in a glove box with the bare hand, an EVA glove without pressure, an EVA glove at operation pressure. Thus, the differential effect on performance of the glove with and without pressure was tested. Bare hand performance was used to “calibrate” the effects. Ten subjects participated in the test setup as a repeated-measures experimental design.
Technical Paper

Use of Quantitative Electromyography (EMG) in the Evaluation of Fatigue Associated with Pressure Glove Work

1989-07-01
891473
Noninvasive EMG was used to evaluate fatigue of the finger flexors, thumb flexor, and wrist extensor muscles associated with hand work. The 1000 series pressure suit glove was used in conjunction with a glove box testing methodology. Determination of the degree of muscle fatigue was based on an analysis of the change in the median frequency of the EMG associated with bare-hand, gloved-hand/0 psid and gloved-hand/4.3 psid work. The methodology for collecting EMG data and the analysis of the median frequency as a physiological means of quantifying muscle fatigue is presented. The intent of this program was to develop objective means of analyzing hand performance for any pressure glove design, and compare it to bare-hand performance.
Technical Paper

The Thermal Control of TDF-1- the First Six Months in Orbit

1989-07-01
891523
The direct broadcasting television satellite TDF-1 has been launched on October 28th, 1988, by ARIANE flight V 26 from KOUROU, French Guyana. After the successful on orbit tests, the five television channels have been activated on the 15th of November. One of the key features of this satellite consists in the sophisticated design of the heat pipe network used for the thermal control of the telecommunication payload. This network is composed of 86 constant conductance heat pipes of different diameters, corresponding to a total cumulative length of about 120 meters, and arranged along the three axes of the spacecraft body. The paper describes the thermal control design of this satellite and summarizes the development plan selected in connection with the constraints linked with the heat pipe utilisation. The second part is an overview of the in-orbit performance of the thermal control system during the first Month of operational utilisation.
Technical Paper

BAF - an Advanced Ecological Concept for Air Quality Control

1989-07-01
891535
An advanced ecological concept for air quality control of space inhabited vehicles/stations is proposed for the removal of contaminants from biological origin, essentially from the crew itself, and from non-biological origin like from material off-gassing and gas leakage. The principle of the system is based on the combination of a support/sorbant material colonised by selected innocuous microorganisms in a near resting state, catabolising the contaminants to inert chemicals, mainly carbon dioxide, water and salts. Several advantages are expected over pure physico-chemical systems, namely adaptability to unexpected contaminants, to an evolution of their production rate, and ability to recover normal efficiency after accidental poisoning.
Technical Paper

Paramagnetic O2 - Sensor (ParaO)

1989-07-01
891536
Oxygen is one of the few gases of technical importance which are paramagnetic. Furthermore the paramagnetic effect of oxygen - i. e. its permeability - is much higher than the magnetic constant of other gases of importance. Thus the paramagnetism of oxygen may be used to determine the partial pressure of oxygen specifically.
Technical Paper

Performance Characterization of water Recovery and water Quality from Chemical/Organic Waste Products

1989-07-01
891509
Water reclamation subsystems currently being evaluated for the Space Station Freedom are designed primarily to reclaim water from waste streams containing low to moderate levels of organics/inorganics, including chemical additives to control microorganism proliferation. Wastes containing high organic content (solids), especially those containing chemical and bioprocess fluids, present potential risks for compromising operational integrity of these subsystems. Looking beyond near-term needs to reclaim water from primarily crew-derived waste streams, refurbishment and process characterization of a waste water management system capable of processing wastes containing high concentrations of organic/inorganic materials has been initiated. The process combines low temperature/pressure to vaporise water with high temperature catalytic oxidation to decompose volatile organics. The reclaimed water is of potable quality and has a high potential for maintenance under sterile conditions.
Technical Paper

Electrochemical Incineration of Wastes

1989-07-01
891510
A low temperature electrolysis process has been developed for the treatment of solid waste material and urine. Experiments are described in which organic materials are oxidized directly at the surface of an electrode. Also, hypochlorite is generated electrochemically from chloride component of urine. Hypochlorite can act as a strong oxidizing agent in solution. The oxidation takes place at 30-60°C and the gaseous products from the anodic reaction are carbon dioxide, nitrogen, oxygen. Hydrogen is formed at the cathode. Carbon monoxide, and nitrogen oxides and methane were not detected in the off gases. Chlorine was evolved at the anode in relatively low amounts.
Technical Paper

Atmosphere Control for Plant Growth Flight Experiments

1989-07-01
891587
Biological systems flown in space, as either experiments or part of the spacecraft habitat Environmental Control/Life Support System, will require controlled environments to optimize results. Plant growth flight experiments have, up to this time, used or planned on using unconditioned crew compartment atmosphere or bottled gases. Use of unconditioned crew compartment atmosphere limits the choice and flexibility of experiments. Bottled gases are heavy and take up valuable space. Life Systems, Inc. sponsored by the National Aeronautics and Space Administration's Kennedy Space Center, Bionetics Corporation, and internal funds has developed a small (115 cm3), lightweight (270 g) unit which controls the two primary atmosphere parameters for plant growth experiments-pCO2 and trace contaminant levels. The unit is capable of providing variable pCO2 outlet levels as specified by the experimenter.
Technical Paper

A Telescience Monitoring and Control Concept for a CELSS Plant Growth Chamber

1989-07-01
891585
This paper presents a technical and operational approach for distributed monitoring and control of a Controlled Ecological Life Support System (CELSS) Plant Growth Chamber (PGC). This operational mode, referred to as telescience, will allow geographically separate investigators to conduct an experiment as if they were collocated. The overall control system includes the controllers for the PGC subsystems (lighting, heating, ventilation and air conditioning, nutrient delivery, vital gases, etc.), a local master controller, and the control capabilities of the remote controllers. The investigators interaction with their data and each other is made possible through interoperable computer workstations. Moving operations labor to a remote site can result in a significant savings in local crew time. It can also increase the quality of the operation/product by bringing remote expertise into an activity where the local crew has limited capability.
Technical Paper

Study of Advanced System for Air Revitalization

1989-07-01
891575
To support sustained manned activities in an enclosed environment in space vehicles such as the Space Station (SS), a respirable air supply system is essential and optimization should be aimed at in the design of such a system. For cabin air revitalization, it is indispensable to remove carbon dioxide (CO2) and other gaseous contaminants generated from crew and/or non-metalic materials to prevent them from accumulating. In addition to the above functions, oxygen (O2) recovery function using trapped CO2 is indispensable for the Air Revitalization System (ARS) because a reduction of resupply materials from ground is strictly required. This paper presents and an outline of a feasibility study of the ARS in which system optimization is made.
Technical Paper

Medical Guidelines for Protecting Crews with Flame-Suppressant Atmospheres

1989-07-01
891596
Flames are a serious hazard to crewmembers confined in sealed cabins. The flame hazard can be diminished by lowering the oxygen concentration, this being accomplished by reducing the partial pressure of oxygen or raising the partial pressure of nitrogen in the chamber. Excessive modification of the atmosphere can cause one of the following medical problems; hypoxia, barotrauma, nitrogen narcosis, or decompression sickness. These conditions establish the basic medical criteria for designing habitable atmospheres to reduce the flame hazard of fires. Experimental evidence supports the use of 130 torr oxygen to design habitable, flame-suppresant atmospheres.
Technical Paper

A Semi-Continuos Biotreatment Protocol for Chlorinated Ethanes: Application To The Aerospace Industry

1989-07-01
891598
A biological treatment process employing immobilized microbial populations was field tested on contaminated ground water having elevated concentrations of volatile organics, primarily ethylene dichloride (EDC), 1, 1 dichloroethane and 1,1,2 trichoroethane. The process, consisting of a 75 L packed bed reactor containing specific adapted microbial strains immobilized on a porous diatomaceous earth support, was operated in a plug flow configuration over a 14 day period in a semi-continuous mode, i.e., draw and fill. General process measurements included temperature, pH, and titrated chlorides. Microbial adenosine triphoshate (ATP) measurements provided estimates on immobilized biomass performance.
Technical Paper

Decompression Sickness Risks for European EVA

1989-07-01
891546
The design of a European space suit with a design pressure of 500 hPa requires a re-evaluation of the protective procedures -for space suit decompression. By analysis of the relevant literature, published decompression data from altitude chamber exposures, nitrogen/oxygen (nitron) saturation dives, and various decompression tables, an R factor of 1.2 and a tissue half-time (t1/2) of 360 minutes in a single-tissue model have been identified as appropriate operational values. On the basis of an acceptable risk level of approximately IX, oxygen prebreathing times are proposed for (a) direct pressure reduction froo 1013 hPa to a suit pressure of 500 hPa, and (b) staged decompression using a 700 hPa intermediate stage in the spacecraft cabin. In addition, factors which influence individual susceptibility to DCS are identified. First evidence is found for body fat, body weight and age.
Technical Paper

CO2 Processing and O2 Reclamation System Selection Process for Future European Space Programmes

1989-07-01
891548
This paper describes the process used to select the physico-chemical system configuration to meet the requirements of manned European space development plans from the year 2005 onwards. From the investigated sixty four candidates, eight candidate system configurations were preselected from which one baseline configuration was finally selected. This will enable the European space industry to identify and establish the required capabilities and technologies in Europe. The selection process took available technology, cost impact, oxygen, water, carbon and hydrogen loop closure considerations and a synergetic approach with the propulsion system into account. Both quantitative and qualitative assessments were used.
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