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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Fostering Continuous Improvement in a Changing Business Context. Textron Systems, Wilmington, Massachusetts, 1998,1999,2000

Cutcher-Gershenfeld, Joel January 2001 (has links)
This is a large non-union facility implementing systems change initiatives in a rapidly changing business context. Textron has been an important contributor to the U.S. defense aerospace business for five decades. Textron is a prime contractor with the U.S. government and supplier for other technologies. Textron sees workplace change initiatives as key to business success. It seeks performance gains through employee training and development. Textron Systems illustrates the ever-changing challenge of aligning employment systems with business strategy in the aerospace industry. It can sustain major change initiatives and is vulnerable to the swings that come with each new business contract. A combination of training, organizational development and work restructuring activities are being implemented. Even so, they cannot fully mitigate the instability associated with the defense aerospace sector.

Fostering Workplace Innovation and Labor-Management Partnership: The Challenge of Strategic Shifts in Business Operations at Pratt & Whitney (United Technologies)

Barrett, Betty January 2001 (has links)
The closing of the military jet engine side of the facility and laying off of more than half of the workforce was an unanticipated form of instability faced in this case. The study had begun in order to document innovations between the IAM local and local area management centering on establishing a team-based work system and joint training systems. While important as innovations, these efforts did not convince Connecticut managers to maintain the work in this location. Ultimately, neither local union or local management efforts were sufficient to overcome the instability associated with broad corporate strategies around the movement of work.

From Three to One: Integrating a High Performance Work Organization Process, Lean Production and Activity Based Costing Change Initiatives. Boeing Corporation, Wichita, Kansas, IAM, 2000.

Kochan, Thomas January 2000 (has links)
In 1997, Boeing and IAM launched an HPWO after introducing lean production initiatives in 1994 and Activity Based Costing (ABC) in 1996. Management and union leaders wanted to empower the workforce and enhance the competitiveness of the operations. After a slow and difficult path of diffusion, they need to decide how to best integrate these separate improvement programs into a single initiative. Boeing's engineering culture needs to work with the pragmatic workforce in Wichita. Workers fear losing products and projects to other Boeing facilities and have concerns about leadership turnover and follow-through. The HPWO helped managers recognize the importance of unions. Still, all three initiatives need a broader base of support.

A Decade of Learning: International Association of Machinists/Boeing Joint Programs. Seattle, Washington, 2001.

Kochan, Thomas January 2001 (has links)
This national joint training initiative, funded at 14 cents per payroll hour worked, represents a key institutional innovation. Negotiated under Article 20 of the contract, this program has evolved over its first decade of experience. It expands life long learning to nearly all hourly workers. Major components of the program include: Layoff and Redeployment assistance, The Health and Safety Institute; Career and Personal Development; Classroom Training; Personal Enrichment, and High Performance Work Organization (HPWO). After a decade, the joint programs have reached between 40 and 50% of bargaining unit employees. Lean initiatives at Boeing are largely separate from the National Joint Training programs. The joint training programs have attractive design features and a steady stream of funds - so perhaps they should be more tightly linked. The program is jointly governed and staffed and thereby provides shared ownership from management, the union and the workforce. Its full potential will only be realized, however, when line managers see it as a core resource.

The Aerospace Environmental Hazards: Diagnosis and Proposals for International Remedies

Valero Briceno, Hidalgo A. January 1981 (has links)

Aerospace strategy for the aerospace nation

Wright, Stephen E. January 1900 (has links)
Thesis--School of Advanced Airpower Studies, Maxwell Air Force Base, Ala., 1992-93. / Title from title screen (viewed Nov. 7, 2003). "August 1994." Includes bibliographical references.

An experimental investigation of the effect of vortex generators on the aerodynamic characteristics of a NACA 0021 airfoil undergoing large amplitude pitch oscillations

Rueger, Mathew Lee January 1988 (has links)
No description available.

Control of Boundary Layer Separation and the Wake of an Airfoil using ns-DBD Plasma Actuators

Ashcraft, Timothy Allen January 2016 (has links)
The efficacy of nanosecond pulse driven dielectric barrier discharge (ns-DBD) plasma actuators for boundary layer separation and wake control is investigated experimentally. A single ns-DBD plasma actuator is placed at the leading edge of a NACA 0012 airfoil model. Both baseline and controlled flow fields are studied using static pressure measurements, Particle Image Velocimetry (PIV) and Constant Temperature Anemometry (CTA). Experiments are primarily performed at Re = 0.74 x 10⁶ and α = 18°. CP, PIV and CTA data show that a forcing frequency of F⁺ = 1.14 is optimal for separation control. CTA surveys of the wake at x/c = 7 indicate three approximate regimes of behavior. Forcing in the range 0.92 < F⁺ < 1.52 results in the best conditions for separation control over the airfoil, but has no dominant signature in the wake at x/c = 7. Excitation in the range of 0.23 < F⁺ < 0.92 produces a single dominant frequency in the wake while F⁺ < 0.23 shows behavior representing a possible impulse response or nonlinear effects. PIV data confirm these observations in all three regimes. Cross-correlations of CTA data are also employed to evaluate the two-dimensionality of the excited wake. The initial results presented here are part of an ongoing effort to use active flow control (AFC), in the form of ns-DBDs, as an enabling technology for the study of unsteady aerodynamics and vortex-body interactions.

Numerical investigations of flow characteristics and aerodynamic parameters of an airfoil with a trailing edge rotary cylinder

Chan, Preston C. T. 13 April 2016 (has links)
<p> The objective of this thesis was to study flow characteristics and aerodynamic parameters of an optimized low Reynolds number airfoil with a rotating cylinder at its trailing edge for application in Micro Aerial Vehicles (MAVs). The airfoil had a chord length, a width, and a thickness of 15.24 cm, 30.48 cm, and 1.6 mm, respectively. Investigations of flow characteristics and aerodynamic parameters were performed using the CFD software, STAR-CCM+, by CD-Adapco. The freestream mean velocity was 10 m/sec. which corresponds to a chord length Reynolds number of 104,400. The simulations were performed at five different Angles of Attack (AOA), 0, 5, 10, 15 and 30 degrees, with and without cylinder rotation. Results indicate 53% improvement in lift to drag ratio of the airfoil at a velocity ratio of 1.66 with rotation, as compared to corresponding condition without cylinder&rsquo;s rotation. Further analyses were conducted with velocity ratios of 1 and 0.53 and the results indicate increased lift to drag ratio in both conditions but not as significant when the velocity ratiofs was at 1.66.</p>

Payload mass improvements of supersonic retropropulsive flight for human class missions to Mars

Fagin, Maxwell H. 29 March 2016 (has links)
<p> Supersonic retropropulsion (SRP) is the use of retrorockets to decelerate during atmospheric flight while the vehicle is still traveling in the supersonic/hypersonic flight regime. In the context of Mars exploration, <i>subsonic</i> retropropulsion has a robust flight heritage for terminal landing guidance and control, but all <i>supersonic</i> deceleration has, to date, been performed by non-propulsive (i.e. purely aerodynamic) methods, such as aeroshells and parachutes.</p><p> Extending the use of retropropulsion from the subsonic to the supersonic regime has been identified as an enabling technology for high mass humans-to-Mars architectures. However, supersonic retropropulsion still poses significant design and control challenges, stemming mainly from the complex interactions between the hypersonic engine plumes, the oncoming air flow, and the vehicle&rsquo;s exterior surface. These interactions lead to flow fields that are difficult to model and produce counter intuitive behaviors that are not present in purely propulsive or purely aerodynamic flight.</p><p> This study will provide an overview of the work done in the design of SRP systems. Optimal throttle laws for certain trajectories will be derived that leverage aero/propulsive effects to decrease propellant requirements and increase total useful landing mass. A study of the mass savings will be made for a 10 mT reference vehicle based on a propulsive version of the Orion capsule, followed by the 100 mT ellipsoid vehicle assumed by NASA&rsquo;s Mars Design Reference Architecture.</p>

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