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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

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

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

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.
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

Metrics and System Analysis

1998-07-13
981746
ALS metrics are required to meet congressional requirements, but if they are well thought out will help focus technical efforts in appropriate and productive directions. This paper addresses the benefits and limitations of using equivalent system mass as an ALS metric.
Technical Paper

Improved NDI Techniques for Aircraft Inspection

1998-11-10
983105
Through the use of an “Integrated Product Team” approach and new inspection techniques incorporating the latest in imaging capabilities and automation, the costs of some man-power intensive tasks can now be drastically reduced. Also, through the use of advanced eddy current techniques, the detectable size of cracks under flush-head fasteners can be reduced while maintaining reliable inspection. This article describes the evaluation and results obtained using eddy current technology to determine the minimum fasteners, Secondly, it describes the integrated efforts of engineers at Boeing DPD and Northwest Airlines in the successful application of MAUS eddy current scanning of the DC-10 circumferential and axial crow splices. The eddy current scanning greatly reduced the man-hour effort required for the existing radiographic inspection
Technical Paper

Dynamic Thermal Management System Modeling of a More Electric Aircraft

2008-11-11
2008-01-2886
Advancements in electrical, mechanical, and structural design onboard modern more electric aircraft have added significant stress to the thermal management systems (TMS). A thermal management system level analysis tool has been created in MATLAB/Simulink to facilitate rapid system analysis and optimization to meet the growing demands of modern aircraft. It is anticipated that the tracking of thermal energy through numerical integration will lead to more accurate predictions of worst case TMS sizing conditions. In addition, the non-proprietary nature of the tool affords users the ability to modify component models and integrate advanced conceptual designs that can be evaluated over multiple missions to determine the impact at a system level.
Technical Paper

Drilling Mixed Stack Materials for the BOEING 787

2010-09-28
2010-01-1867
The new combinations such as composites and titanium that are being used on today's new airplanes are proving to be very challenging when drilling holes during manufacturing and assembly operations. Gone are the days of hand drilling with high speed steel drills through soft aluminum structure, after which aluminum rivets would be swaged into those holes with very generous tolerances. The drilling processes today need to use cutter materials hard enough and tough enough to cut through hard metals such as titanium, yet be sharp enough to resistant abrasion and maintain size when drilling through composites. There is a constant search for better cutters and drills that can drill a greater number of holes. The cost of materials used in today's aircraft is much higher. The cutting tools are more expensive and the hole tolerances are much tighter.
Technical Paper

ACOFE.com (Air Cooled Oil Free Engine)

2004-03-08
2004-01-0986
Reciprocating engines may remain as the prime movers of most vehicles even after fossil fuels are exhausted. Three simple ideas have been chiseled into shape from several theoretical and practical angles. These concept designs promote the modification of the chamber, the valves, and the connecting rod of the conventional reciprocating engines.
Technical Paper

ESM History, Capability, and Methods

2003-07-07
2003-01-2630
Equivalent system mass (ESM) was defined in 1997 as an integral part of the Advanced Life Support project metric. It is particularly suited to comparing technologies that differ in mass, volume, power, cooling, and crew time during the early phases of a program. In principle, ESM can also be used to compare technologies that differ in other parameters. In practice, the necessary data is generally not available, and this limits this application. ESM has proven to be a useful tool. Like any tool, its strengths and weaknesses must be understood. This paper documents the history, capability and methods used in connection with ESM.
Technical Paper

Clarifying Objectives and Results of Equivalent System Mass Analyses for Advanced Life Support

2003-07-07
2003-01-2631
This paper discusses some of the analytical decisions that an investigator must make during the course of a life support system trade study. Equivalent System Mass (ESM) is often applied to evaluate trade study options in the Advanced Life Support (ALS) Program. ESM can be used to identify which of several options that meet all requirements are most likely to have lowest cost. It can also be used to identify which of the many interacting parts of a life support system have the greatest impact and sensitivity to assumptions. This paper summarizes recommendations made in the newly developed ALS ESM Guidelines Document and expands on some of the issues relating to trade studies that involve ESM.
Technical Paper

Costs and Benefits of Bioreactors

2002-07-15
2002-01-2523
Different options have been examined for providing minerals to plants for bioregeneration. The baseline option is to ship the minerals. The equivalent system mass of two different bioreactor systems for recycling a portion of these minerals, a fixed-film bioreactor and a stirred-tank reactor are calculated. Either option could reduce the ESM for providing these minerals for a 15-year mission to Mars, with 50% food closure.
Technical Paper

Impact of Waste Processing Options on System Closure and Mission ESM

2002-07-15
2002-01-2519
The technology selected for waste processing has a major effect on system closure and mission equivalent system mass (ESM). In particular, recovery of the water content of solid waste can make the difference between a mission being water poor and water rich. Potential alternative sources of water that need to be considered would include recovery of water from carbon dioxide reduction, and in situ resources. This paper looks at a range of waste-processing scenarios and calculated system ESM impacts related to these options. The lowest ESM approach is generally storage or dumping. However, other issues also need to be considered. Processing may be driven by requirements such as the need to recover commodities like water, prevent release of toxic gases into the spacecraft environment, planetary protection requirements, and interface loads.
Technical Paper

Enhanced Security Flight Deck Doors-Commercial Airplanes

2002-11-05
2002-01-2998
In the wake of the 9/11/2001 hijacking events, the Federal Aviation Administration (FAA) has emphasized the need for enhanced flight deck doors on commercial airplanes. The paper describes enhanced flight deck door, which meets the new FAA requirements for intrusion resistance and ballistic protection. In addition, the new door meets the existing requirements for rapid decompression, flight crew security and rescue.
Technical Paper

Unique Aspects Involved in the Robotic Painting of Commercial Aircraft Structures

2011-10-18
2011-01-2790
The use of paint automation in commercial aircraft production is being studied to reduce process cycle times, provide a higher quality paint finish, lower emissions, and increase process consistency. The cost of new aircraft paint hangars and increasing production rates is driving a need for increased capacity in existing facilities by using new coatings and technology. Testing of robotic painting at Boeing has uncovered unique differences between aerospace and automotive applications. Paint cure times, number of paint colors, environment control, and part size considerations are some of the issues that make aerospace application of coatings more difficult than automotive applications. Understanding the unique factors involved in the robotic application of commercial aerospace coatings is important for future advancements in application technology, gains in aircraft paint hangar capacity, delivering quality coating finishes, and lowering environmental footprint.
Technical Paper

Recommendations for Clothing Systems for Advanced Missions

2006-07-17
2006-01-2248
Clothing can constitute a major logistical problem for advanced missions. Current and historical clothing systems for space missions have been assessed, as has the viability of using a washing machine to clean (recycle) clothing. Modern fabrics can reduce the mass and increase the functionality of clothing, including reducing the risk of fire, for all missions. The increased cost of acquisition of even high tech commercial off the shelf (COTS) items is trivial compared to the cost of shipping the clothing and disposing of it as trash. Washing can be cost effective when water is recycled efficiently, provided the mission is long enough. The breakeven time for clothes-washing depends on the specifics of the mission, particularly the mass equivalencies of infrastructure, but is of the order of weeks rather than years.
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