Search Results

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.

At Boeing’s commercial aircraft production in Everett Washington, the organization that supplies parts to the factory floor (known internally as Company 625) is revising their methods. A new process will deliver parts in kits that correspond to the installation plans used by the mechanics. Several alternative methods are under review. The authors used simulation methods to evaluate and compare these alternatives. This study focuses on the category of parts known as standard fasteners (‘standards’). Through direct observation, interviews with experts, as well as time and motion study, the process flow of the kitting operation was mapped A simulation model was created using the simulation software ARENA to examine two scenarios: the current kitting operation in the factory cribs and the proposed centralization of kitting operation in the Company 625.

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%).

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.

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.

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.

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.

Rational design for fire safety necessarily includes consideration of risk tradeoffs that tend to reduce one risk but may increase another. Traditional engineering design criteria can be supplemented with important factors that rely on expertise from other disciplines. Engineering analysis may be able to address reduction in fire risk due to the introduction of new technology, but may not address the social costs associated with this new technology. For example, the resultant increase in vehicle cost may prevent some people from purchasing a vehicle (impacting individuals' lives), may reduce the number of vehicles sold (impacting manufacturers), and may reduce taxes collected (impacting the government). This must be weighed against decreased risk of property damage, injury, and fatality due to fire. In this paper, the methods of benefit-cost analysis from economics were applied to make this evaluation.

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.

An automotive propulsion concept is presented which utilizes liquid nitrogen as the working fluid for an open Rankine cycle. Ambient heat exchangers are used to power an engine that is configured to maximize heat transfer during the expansion stroke. If sufficient heat input during the expansion process can be realized then this cryogenic propulsive system would provide greater automotive ranges and lower operating costs than those of electric vehicles currently being considered for mass production. The feasibility of meeting this engineering challenge has been evaluated and several means of achieving quasi-isothermal expansion are discussed.

In applications ranging from design of customized vehicle interiors to virtual testing of biomedical devices, the processes of modeling, design and analysis involve the simultaneous treatment of artifacts (i.e., parts designed by humans) and anatomical structures. An inherent conflict arises because the geometric descriptions are completely different. Artifact descriptions are typically the output of computer-aided design (CAD) software and consist of a collection of parametric patches that comprise the boundary of the artifact. In stark contrast, the native description of an anatomical structure typically consists of an image stack obtained using a volumetric scanning technology such as computed tomography (CT) or magnetic resonance imaging (MRI). Current practice for simultaneously dealing with both categories of entities involves working primarily in the world of CAD.

In order to reduce painful and injurious shear stresses for lower limb amputees, prosthetic ankle joints need to provide torsional control in the transverse plane. This paper attempts to characterize biological ankle function in the transverse plane with simple mechanical elements to assist in the design of a biomimetic prosthetic ankle joint. Motion capture data was collected from ten subjects walking in a straight trajectory to model four states of stance phase. Passive elements were chosen to model the ankle in each state. The ankle was observed to act as a quadratic torsional spring in State 1 and as linear torsional springs in States 2, 3 and 4. The results of this study should assist with the mechanical design and control of a biomimetic torsional prosthesis by suggesting a finite state control system and by providing the stiffness coefficients to be controlled for straight walking.

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.

Map matching determines which road a vehicle is on based on inaccurate measured locations, such as GPS points. Simple algorithms, such as nearest road matching, fail often. We introduce a new algorithm that finds a sequence of road segments which simultaneously match the measured locations and which are traversable in the time intervals associated with the measurements. The time constraint, implemented with a hidden Markov model, greatly reduces the errors made by nearest road matching. We trained and tested the new algorithm on data taken from a large pool of real drivers.

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.

This investigation of the use of cryogens as energy storage media for zero emission vehicles has found that using liquid nitrogen to liquefy the working fluids of one or more closed Rankine power cycles can be an effective means for increasing motive power. System configurations are presented which can realize over 50% of the availability of liquid nitrogen without relying on isothermal expanders. A zero emission vehicle utilizing such a propulsion system would have an energy storage reservoir that can be refilled in a matter of minutes and a range comparable to that of a conventional automobile.

This paper develops and tests algorithms for predicting the end-to-end route of a vehicle based on GPS observations of the vehicle's past trips. We show that a large portion a typical driver's trips are repeated. Our algorithms exploit this fact for prediction by matching the first part of a driver's current trip with one of the set of previously observed trips. Rather than predicting upcoming road segments, our focus is on making long term predictions of the route. We evaluate our algorithms using a large corpus of real world GPS driving data acquired from observing over 250 drivers for an average of 15.1 days per subject. Our results show how often and how accurately we can predict a driver's route as a function of the distance already driven.

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

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.

One barrier to the use of algae feedstocks as a source of CO2-neutral, renewable liquid fuel is the potential for high processing costs. An important processing step is the extraction of oil from the biomass. While there is substantial industrial experience in lipids from oil seeds, these processes may be unattractive for algal fuel oil due to high costs. Laboratory data suggest, however, that the relatively fragile nature of algal biomass may speed the mass transfer processes that control the extraction rate, and thus either reduce equipment size or allow increased throughput. In the present paper, laboratory-scale extraction data are used to develop a finite difference model of a full-scale extractor. The results indicate that such an extractor may have an increase in throughput of a factor of 5-10 without losing extraction efficiency.