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Tailored Conversion Coatings for Enhanced Adhesion to Metal

2012-03-21
As a result of recommendation from the Augustine Panel, the direction for Human Space Flight has been altered from the original plan referred to as Constellation. NASA's Human Exploration Framework Team (HEFT) proposes the use of a Shuttle Derived Heavy Lift Launch Vehicle (SDLV) and an Orion derived spacecraft (salvaged from Constellation) to support a new flexible direction for space exploration. The SDLV must be developed within an environment of a constrained budget and a preferred fast development schedule. Thus, it has been proposed to utilize existing assets from the Shuttle Program to speed development at a lower cost. These existing assets should not only include structures such as external tanks or solid rockets, but also the Flight Software which has traditionally been a ?long pole? in new development efforts. The avionics and software for the Space Shuttle was primarily developed in the 70's and considered state of the art for that time.
Journal Article

Application of Synthetic Jets to Enhance the Performance of a Vertical Tail

2013-09-17
2013-01-2284
The performance enhancement of a vertical tail provided by aerodynamic flow control could allow for the size of the tail to be reduced while maintaining similar control authority. Decreasing tail size would create a reduction in weight, drag, and fuel costs of the airplane. The application of synthetic jet actuators on improving the performance of the vertical tail was investigated by conducting experiments on 1/9th and 1/19th scale wind tunnel models (relative to a Boeing 767 tail) at Reynolds numbers of 700,000 and 350,000, respectively. Finite-span synthetic jets were placed slightly upstream of the rudder hinge-line in an attempt to reduce or even eliminate the flow separation that commences over the rudder when it was deflected to high angles. Global force measurements on the 1/9th scale model showed that the flow control is capable of increasing side force by a maximum of 0.11 (19%). The momentum coefficient that created this change was relatively small (Cμ = 0.124%).
Journal Article

Optimization of Spatially Varying Fiber Paths for a Symmetric Laminate with a Circular Cutout under Remote Uniaxial Tension

2015-09-15
2015-01-2609
Minimizing the stress concentrations around cutouts in a plate is often a design problem, especially in the Aerospace industry. A problem of optimizing spatially varying fiber paths in a symmetric, linear orthotropic composite laminate with a cutout, so as to achieve minimum stress concentration under remote unidirectional tensile loading is of interest in this study. A finite element (FE) model is developed to this extent, which constraints the fiber angles while optimizing the fiber paths, proving essential in manufacturing processes. The idea to be presented could be used to derive fiber paths that would drastically reduce the Stress Concentration Factor (SCF) in a symmetric laminate by using spatially varying fibers in place of unidirectional fibers. The model is proposed for a four layer symmetric laminate, and can be easily reproduced for any number of layers.
Journal Article

Health Ready Components-Unlocking the Potential of IVHM

2016-04-05
2016-01-0075
Health Ready Components are essential to unlocking the potential of Integrated Vehicle Health Management (IVHM) as it relates to real-time diagnosis and prognosis in order to achieve lower maintenance costs, greater asset availability, reliability and safety. IVHM results in reduced maintenance costs by providing more accurate fault isolation and repair guidance. IVHM results in greater asset availability, reliability and safety by recommending preventative maintenance and by identifying anomalous behavior indicative of degraded functionality prior to detection of the fault by other detection mechanisms. The cost, complexity and effectiveness of the IVHM system design, deployment and support depend, to a great extent, on the degree to which components and subsystems provide the run-time data needed by IVHM and the design time semantic data to allow IVHM to interpret those messages.
Journal Article

Computational Fluid Dynamics Calculations of Turbocharger's Bearing Losses

2010-05-05
2010-01-1537
Fuel consumption in internal combustion engines and their associated CO2 emissions have become one of the major issues facing car manufacturers everyday for various reasons: the Kyoto protocol, the upcoming European regulation concerning CO2 emissions requiring emissions of less than 130g CO2/km before 2012, and customer demand. One of the most efficient solutions to reduce fuel consumption is to downsize the engine and increase its specific power and torque by using turbochargers. The engine and the turbocharger have to be chosen carefully and be finely tuned. It is essential to understand and characterise the turbocharger's behaviour precisely and on its whole operating range, especially at low engine speeds. The characteristics at low speed are not provided by manufacturers of turbochargers because compressor maps cannot be achieve on usual test bench.
Journal Article

A Balanced Approach for Securing the OBD-II Port

2017-03-28
2017-01-1662
The On-Board Diagnostics II (OBD-II) port began as a means of extracting diagnostic information and supporting the right to repair. Self-driving vehicles and cellular dongles plugged into the OBD-II port were not anticipated. Researchers have shown that the cellular modem on an OBD-II dongle may be hacked, allowing the attacker to tamper with the vehicle brakes. ADAS, self-driving features and other vehicle functions may be vulnerable as well. The industry must balance the interests of multiple stakeholders including Original Equipment Manufacturers (OEMs) who are required to provide OBD function, repair shops which have a legitimate need to access the OBD functions, dongle providers and drivers. OEMs need the ability to protect drivers and manage liability by limiting how a device or software application may modify the operation of a vehicle.
Journal Article

Body Join Drilling for One-Up-Assembly

2013-09-17
2013-01-2296
Over 1,200 large diameter holes must be drilled into the side-of-body join on a Boeing commercial aircraft's fuselage. The material stack-ups are multiple layers of primarily titanium and CFRP. Due to assembly constraints, the holes must be drilled for one-up-assembly (no disassembly for deburr). In order to improve productivity, reduce manual drilling processes and improve first-time hole quality, Boeing set out to automate the drilling process in their Side-of-Body join cell. Implementing an automated solution into existing assembly lines was complicated by the location of the target area, which is over 15 feet (4 meters) above the factory floor. The Side-of-Body Drilling machines (Figure 1) are capable of locating, drilling, measuring and fastening holes with less than 14 seconds devoted to non-drilling operations. Drilling capabilities provided for holes up to ¾″ in diameter through stacks over 4.5″ thick in a titanium/CFRP environment.
Journal Article

Development of a Lube Filter with Controlled Additive Release for Modern Heavy Duty Diesel Engines Utilizing EGR

2008-10-07
2008-01-2644
As on-highway heavy-duty diesel engine designs have evolved to meet tighter emission regulations, the crankcase environment for heavy-duty engine lubricants has become more challenging. The introduction of Exhaust Gas Recirculation (EGR) has allowed for significant reductions of exhaust emissions, but has led to increased oxidation and acid build-up in the lubricant. Engine lubricant quality is important to help ensure engine durability, engine performance, and reduce maintenance downtime. Increased acidity and oxidation accelerate the rate at which the lubricant quality is degraded and hence shorten its' useful life. This paper explores the use of a lube filter with a controlled additive release to maintain lubricant quality.
Journal Article

Functional Mobility Testing: A Novel Method to Create Suit Design Requirements

2008-06-17
2008-01-1857
This study was performed to aide in the creation of design requirements for the next generation of space suits that more accurately describe the level of mobility necessary for a suited crewmember through the use of an innovative methodology utilizing functional mobility. A novel method was utilized involving the collection of kinematic data while 20 subjects (10 male, 10 female) performed pertinent functional tasks that will be required of a suited crewmember during various phases of a lunar mission. These tasks were selected based on relevance and criticality from a larger list of tasks that may be carried out by the crew. Kinematic data was processed through Vicon BodyBuilder software to calculate joint angles for the ankle, knee, hip, torso, shoulder, elbow, and wrist. Maximum functional mobility was consistently lower than maximum isolated mobility.
Journal Article

Incorporation of Atmospheric Neutron Single Event Effects Analysis into a System Safety Assessment

2011-10-18
2011-01-2497
Atmospheric Neutron Single Event Effects (SEE) are widely known to cause failures in all electronic hardware, and cause proportionately more failures in avionics equipment due to the use altitude. In digital systems it is easy to show how SEE can contribute several orders of magnitude more faults than random (hard) failures. Unfortunately, current avionics Safety assessment methods do not require consideration of faults from SEE. AVSI SEE Task Group (Aerospace Vehicle Systems Institute Committee #72, on Mitigating Radiation Effects in Avionics) is currently coordinating development of an atmospheric Neutron Single Event Effects (SEE) Analysis method. This analysis method is a work in progress, in close collaboration with SAE S-18 and WG-63 Committees (Airplane Safety Assessment Committee). The intent is to include this method as part of current revisions to ARP4761 (Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment).
Journal Article

An Overview of the V&V of Flight-Critical Systems Effort at NASA

2011-10-18
2011-01-2560
As the US is getting ready for the Next Generation (NextGen) of Air Traffic System, there is a growing concern that the current techniques for verification and validation will not be adequate for the changes to come. The JPDO (in charge of implementing NextGen) has given NASA a mandate to address the problem and it resulted in the formulation of the V&V of Flight-Critical Systems effort. This research effort is divided into four themes: argument-based safety assurance, distributed systems, authority and autonomy, and, software intensive systems. This paper presents an overview of the technologies that will address the problem.
Journal Article

Augmented Reality and Other Visualization Technologies for Manufacturing in Boeing

2011-10-18
2011-01-2656
The Efficient Assembly, Integration & Test (EAIT) team at Boeing Research & Technology, Boeing's central technology organization, is working on multiple implementations of Augmented Reality to aid assembly at the satellite production facility in El Segundo, CA. This presentation will discuss our work to bring an Augmented Reality tool to the shop floor, integrating product design and manufacturing techniques into a synergistic backbone and how this approach can support the delivery of engineering design intent on the shop floor. The team is developing a system to bring designer's 3D CAD models to the technicians on the shop floor, and spatially register them to live camera views of production hardware. We will discuss our work in evaluating multiple motion captures systems, how we integrated a Vicon system with Augmented Reality software, and our development of a user interface allowing technicians to manipulate the graphical display.
Journal Article

Technical Improvements to the ASAT2 Boeing 777 Spar Assembly Cell

2011-10-18
2011-01-2707
Electroimpact and Boeing are improving the efficiency and reliability of the Boeing 777 spar assembly process. In 1992, the Boeing 777 spar shop installed Giddings and Lewis spar machines with Electroimpact Inc. EMR(1) (Electromagnetic Riveting) technology. In 2011, Electroimpact Inc. began replacing the original spar machines with next generation assembly machines. The new carriages incorporate a number of technical improvements and advancements over the current system. These technical advancements have facilitated a 50% increase in average cycle rate, as well as improvements to overall process efficiency, reliability and maintainability. Boeing and Electroimpact have focused on several key technology areas as opportunities for significant technical improvements.
Journal Article

Incorporating Atmospheric Radiation Effects Analysis into the System Design Process

2012-10-22
2012-01-2131
Natural atmospheric radiation effects have been recognized in recent years as key safety and reliability concerns for avionics systems. Atmospheric radiation may cause Single Event Effects (SEE) in electronics. The resulting Single Event Effects can cause various fault conditions, including hazardous misleading information and system effects in avionics equipment. As technology trends continue to achieve higher densities and lower voltages, semiconductor devices are becoming more susceptible to atmospheric radiation effects. To ensure a system meets all its safety and reliability requirements, SEE induced upsets and potential system failures need to be considered. The purpose of this paper is to describe a process to incorporate the SEE analysis into the development like-cycle. Background on the atmospheric radiation phenomenon and the resulting single event effects, including single event upset (SEU) and latch up conditions is provided.
Journal Article

Thermal Simulation and Testing of Expanded Metal Foils Used for Lightning Protection of Composite Aircraft Structures

2013-09-17
2013-01-2132
Since the 1960's, lightning protection of aircraft has been an important design aspect, a concern for the flying public, aircraft manufacturers and the Federal Aviation Administration (FAA). With the implementation of major aircraft structures fabricated from carbon fiber reinforced plastic (CFRP) materials, lightning protection has become a more complicated issue to solve. One widely used material for lightning strike protection of CFRP structures within the aerospace industry is expanded metal foil (EMF). EMF is currently used in both military and commercial passenger aircraft. An issue that has historically been an area of concern with EMF is micro cracking of paint on the composite structure which can result in corrosion of the metal foil and subsequent loss of conductivity. This paper addresses the issues of stress and displacement in the composite structure layup which contribute to paint cracking caused by aircraft thermal cycling.
Journal Article

Energy Finite Element Analysis Developments for Vibration Analysis of Composite Aircraft Structures

2011-05-17
2011-01-1734
The Energy Finite Element Analysis (EFEA) has been utilized successfully for modeling complex structural-acoustic systems with isotropic structural material properties. In this paper, a formulation for modeling structures made out of composite materials is presented. An approach based on spectral finite element analysis is utilized first for developing the equivalent material properties for the composite material. These equivalent properties are employed in the EFEA governing differential equations for representing the composite materials and deriving the element level matrices. The power transmission characteristics at connections between members made out of non-isotropic composite material are considered for deriving suitable power transmission coefficients at junctions of interconnected members. These coefficients are utilized for computing the joint matrix that is needed to assemble the global system of EFEA equations.
Technical Paper

Mojacar Brake Wear and NVH: Dyno Simulation Concept

2007-10-07
2007-01-3959
Efficient development and testing of brake systems requires further substitution of expensive and time consuming vehicle testing by appropriate dynamometer testing. Some of the current simulation methods do not reflect the needs of engineering and the progress made in the development of test equipment. The lack of suitable procedures may cause unexpected delays in the realization of projects. Road load simulations for lifetime prediction on brake dynamometers have a long history, however never got a real break-through in Europe - possibly because the prediction quality and efficiency did not satisfy. This paper concentrates first on the analysis of the vehicle data recorded in Mojacar (Spain) which is a sign-off test for wear and noise for brands of Ford Motor Company for European market. Specific attention is given to different types of driving resistances and road profiles and to consideration of different methods for numerical description and comparison of road load data.
Technical Paper

Boeing Crew Exploration Vehicle Environmental Control & Life Support System Architecture Overview

2007-07-09
2007-01-3043
The Boeing Company under the teaming agreement with the Northrop Grumman Systems Corporation and in compliance with the NASA Phase 1 contract had the responsibilities for the CEV architecture development of the Environmental Control and Life Support (ECLS) system under the NASA Phase 1 contract. The ECLS system was comprised of the various subsystems which provided for a shirt-sleeve habitable environment for crew to live and work in the crew module of the CEV. This architecture met the NASA requirements to ferry cargo and crew to ISS, and Lunar sortie missions, with extensibility to long duration missions to Moon and Mars. This paper provides a summary overview of the CEV ECLS subsystems which was proposed in compliance with the contract activities.
Technical Paper

Assessment of Silver Based Disinfection Technology for CEV and Future US Spacecraft

2007-07-09
2007-01-3258
Silver biocide offers a potential advantage over iodine, the current state-of-the-art in US spacecraft disinfection technology, in that silver can be safely consumed by the crew. As such, silver may reduce the overall complexity and mass of future spacecraft potable water systems, particularly those used to support long duration missions. A primary technology gap identified for the use of silver biocide is one of material compatibility. Wetted materials of construction are required to be selected such that silver ion concentrations can be maintained at biocidally effective levels.
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