Thesis (M.S.)--University of Florida, 2004. / Title from title page of source document. Document formatted into pages; contains 88 pages. Includes vita. Includes bibliographical references.

Thesis (M.S.)--University of Florida, 2004. / Title from title page of source document. Document formatted into pages; contains 42 pages. Includes vita. Includes bibliographical references.

Thesis (M.S.)--University of Florida, 2004. / Title from title page of source document. Document formatted into pages; contains 44 pages. Includes vita. Includes bibliographical references.

Thesis--Air Command and Staff College, Air University, Maxwell Air Force Base, April 2005. / "April 2007." Thesis advisor: Lt. Col. James A. Rothenflue. Performed by Air University Press (AUL/LP), Maxwell Air Force Base, Montgomery, Ala. "AU/ACSC/2927/2004-05." Includes bibliographical references (p. 35-37). Also available online from the Air University Research Information Management System (AURIMS) and the DTIC Online Web sites.

Thesis (M.S.)--University of Iowa, 2007. / Supervisor: Thomas Schnell. Includes bibliographical references (leaf 115).

Football is widely regarded as the most popular sport in the world involving over 270 million people from different countries and cultures. It can be argued that the football is one of most important aspects of the game and hence the flight of the ball, if unexpected, can alter the outcome of the game. This thesis provides an engineering perspective and contribution to the continued understanding and improvement of the in-flight performance of FIFA approved footballs. Skilful players will impart spin onto a ball to induce a curve in-flight to try and deceive opponents. This flight is generally smooth, although subtle variations in the orientation and spin rate may cause conditions that affect the path and final ball position, in a manner considered to be unpredictable due to aerodynamic effects. Ball designs and manufacturing techniques are evolving and certain seam configurations are known to induce asymmetric pressure distributions resulting in lateral movement during flight. Aerodynamic research of sport balls has primarily focused on drag and the effects of high spin rates. Studies have shown the introduction of surface roughness affects the boundary layer state compared to a smooth sphere. Surface roughness on a football takes many forms including seam configurations and micro surface textures. The influence of changing the density, distribution and dimensions of the surface roughness with respect to the aerodynamic behaviour has been researched. The principle focus of this thesis is concerned with the influence on the lateral component as a result of applying surface roughness to the outer surfaces. The influence of the surface roughness on the drag and lateral components were determined using established wind tunnel techniques. Real balls and full size prototypes were tested. A mathematical flight model was employed to simulate realistic multiple flight trajectories based on empirical aerodynamic data. Mathematical and statistical techniques, including R.M.S and AutoCorrelation Functions were used to analyse the data. The results from this research showed how small variations in surface texture affected the complex nature of the lateral forces. Trajectories varied significantly depending on initial orientation and slow spin rate sensitivities. In conclusion, ball characterisation techniques were developed that identified lateral deviation and shape measures and considered a gradient profiling approach. Application of these novel parameters through multiple trajectory analysis allowed for an in-flight performance measure of footballs designs.

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2010. / The Cape Peninsula University of Technology (CPUT) Advanced Manufacturing and Technology Laboratory (AMTL) developed an Unmanned Aerial Vehicle (UAV) Technology Demonstrator for the purpose of testing and maturing adaptronic devices. Extending the flight envelope of this unmanned aerial vehicle by increasing its range and endurance is the next step in its development. A seamless variable angle of incidence (sVAI) morphing wing is proposed to increase the lift with little coupling to drag during takeoff; and decrease the drag with little effect on lift during climb, thus increasing the total flight performance of the aircraft. CAD models of the conceptualized sVAI wing and a conventional (CON) wing, as used on the Technology Demonstrator, were modeled. Numerical analyses on these CAD models showed that the sVAI wing concept at a 4° twist decreased the ground roll distance and stall velocity by ±17% and ±31% respectively, as compared to the CON wing in standard takeoff configuration. This allowed for ± 11.7% less power required for takeoff allowing the aircraft to get to its operational altitude quicker, thus saving fuel and reducing energy losses; and increasing range and endurance. The results also showed that the sVAI wing concept could reduce the drag during climb by ± 14%, but the lift is also proportionately reduced thus having little improvement on the climb phase of flight performance. A prototype of the morphing wing was then conceptualized and designed, using a 3D CADmodeler, and then manufactured. The product development chain produced for this morphing wing included two rapid prototyping machines and reverse engineering technologies. The chain allowed for the rapid manufacturing of light weight and intricate parts. The manufactured wing is then incorporated into a test rig to compare the actual morphing ability of the prototype to the theoretical morphing ability of the CADmodel, and thus make flight performance predictions of the actual vehicle. 3D scans were taken of the prototype and then converted to 3D CADfiles. The geometrical and topographical deformation of the prototype was then compared to that of the CAD model showing an average difference of ±1.2% and ±3% at maximum positive and negative configurations, respectively. This allowed one to make the prediction that the sVAI wing will increase the performance of the Technology Demonstrator.

No description available.

It is importance that business organisations focus on providing the best service to their customers. The survival of the organisation depends ultimately on the service provided. This study explores the elements which affect the provision of service excellence to passengers by flight attendants at South African Airways. The study is adequately supported by a proper and detailed literature study which, in turn is founded on an empirical study on the relevant topic. A field study was conducted on the various stakeholders of the supply chain pertaining to in-flight catering to determine what specific viewpoints, suggestions and limitations there were, with regard to existing packaging, catering utensils and galley equipment used by flight attendants personal service on board the aircraft. Alternatives were considered that could result in the improvement of service provided by flight attendants. The literature review within the scope and limitations of the study therefore concentrated on the specific nature and impact that packaging, catering utensils and galley equipment have on the quality service which flight attendants provide to passengers. The study included a detailed investigation into this part of the supply chain. The reality is that flight attendants are the front-line employees not only for the airline they are employed at, but also for all the stakeholders involved in the supply chain of in-flight catering. By not supporting them and providing them with the right tools to execute their duties affects more than one stakeholder in the supply chain. The empirical part of the study was conducted by interviewing flight attendants employed at South African Airways. The objective was to determine the impact that current packaging, catering utensils and equipment had on the execution of service by the flight attendants. A further survey was conducted to determine passenger perception towards packaging, catering utensils and galley equipment. The research findings clearly indicate the problems passengers and flight attendants are experiencing. The findings indicate the impact of passengers and flight attendants and makes suggests (makes recommendations) improvements to reach the objectives of improved service delivery. / Dissertation (MCom (Business Management))--University of Pretoria, 2008. / Business Management / unrestricted

High aspect-ratio flying wing configurations designed for high altitude, long endurance missions are characterized by high flexibility, leading to significant static aeroelastic deformation in flight, and coupling between aeroelasticity and flight dynamics. As a result of this coupling, an integrated model of the aeroelasticity and flight dynamics has to be used to accurately model the dynamics of the flexible flying wing. Such an integrated model of the flight dynamics and the aeroelasticity developed by Patil and Hodges is reviewed in this dissertation and is used for studying the unique flight dynamics of high aspect-ratio flexible flying wings. It was found that a rigid body configuration that accounted for the static aeroelastic deformation at trim captured the predominant flight dynamic characteristics shown by the flexible flying wing. Moreover, this rigid body configuration was found to predict the onset of dynamic instability in the flight dynamics seen in the integrated model. Using the concept of the mean axis, a six degree-of-freedom reduced order model of the flight dynamics is constructed that minimizes the coupling between rigid body modes and structural dynamics while accounting for the nonlinear static aeroelastic deformation of the flying wing. Multi-step nonlinear dynamic inversion applied to this reduced order model is coupled with a nonlinear guidance law to design a flight controller for path following. The controls computed by this flight controller are used as inputs to a time-marching simulation of the integrated model of aeroelasticity and flight dynamics. Simulation results presented in this dissertation show that the controller is able to successfully follow both straight line and curved ground paths while maintaining the desired altitude. The controller is also shown to be able to handle an abrupt change in payload mass while path-following. Finally, the equations of motion of the integrated model were non-dimensionalized to identify aeroelastic parameters for optimization and design of high aspect-ratio flying wings. / Ph. D.