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This thesis presents two methods for initial design propeller optimization using constrained non- linear programming. The process uses the Nelder-Mead simplex algorithm. The Wageningen B-series optimal propeller selection is presented along with the combined annular momentum theory and blade element theory optimization. Both techniques require preliminary hull and engine design characteristics, but do not necessitate extensive background knowledge of pro- pellers and their calculations. A comparison of the two methods shows the combined annular momentum theory and blade element theory optimization produces the more e cient propeller. The optimization programs were designed with a graphic user interface implemented in the programming language Python.

For aircraft that have propellers mounted in front of the wings or tail, the prop wash produced by the propellers can have a strong influence on the aerodynamics of the aircraft. As the accelerated air from the propeller flows over the wings and tail, it can cause an alteration in the aerodynamic forces produced by those surfaces. Thus, an understanding of propeller-wing interactions is essential for the design and analysis of many aircraft. There are multiple existing methods for analyzing the propeller-wing interactions. High order methods, such as wind tunnel testing or computational fluid dynamics, provide very accurate results but come at a high cost in computation or labor. Low-order methods provide results with good accuracy at a significantly lower cost. Thus, it is desirable to use low-order methods for initial design and utilize higher order methods closer to the end of the design phase. Current low-order models for propeller-wing interactions give reasonable results, but have shortcomings in either computational cost or accuracy. In an effort to improve on these existing models, an improved low-order model for propeller-wing interactions is proposed. This improved model utilizes several aerodynamic models such as blade element theory and lifting line theory as well as a novel turbulent prop wash model. The final model is shown to provide more accurate results using efficient numerical methods.

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Unlike conventional propellers, flapping wings may generate large amplitude oscillating forces, which can make them difficult to incorporate into a craft design. This is particularly true for a single, vertically oscillating hydrofoil, as part of a surface water craft where the cyclic lift of the hydrofoil disrupts the craft stability. This thesis begins by reviewing the history of human-powered watercraft with a focus on those having flapping foil propellers. This review combined with a review of the literature provides a balanced overview on how flapping wing propellers are currently designed. Current literature shows that although the mean performance of an oscillating foil has been determined in terms of the Strouhal number and the angle of attack, relatively little describes performance directly in terms of the foil motion. Hence, predicting temporal hydrodynamic forces acting on an oscillating foil is difficult. This provides motivation for research investigating the temporal performance of an oscillating foil directly in terms of its motion. In this thesis, experimental equipment designed to measure the hydrodynamic forces on a heaving object is presented. Key features of the equipment are analysed to show how measurement accuracy is maintained. Experimental measurements of unsteady hydrodynamic forces acting on a heaving cylinder, flat plate, symmetrical foil, and an asymmetrical foil are analysed with respect to the heaving motion. Firstly, the object motion is limited to one degree of freedom; pure heaving with zero forward velocity, to investigate the start-up conditions of the oscillating hydrofoil propeller. Secondly, these results are expanded on by adding a steady forward velocity component to the object motion to investigate how the hydrodynamic forces on the object are affected by the cross-flow. Experimental temporal hydrodynamic force measurements presented in this thesis show how the relative composition of hydrodynamic drag and inertia forces change with oscillating frequency, and forward velocity, affecting the phase, magnitude, and profile of the force cycles. This composition is also influenced by the cross-section of the oscillating object and the presence of a free surface. Current marine engineering equations for unsteady hydrodynamic forces on an object in an oscillating flow are validated for a cylinder. However, they are found to contain significant error when predicting the unsteady hydrodynamic forces on an oscillating hydrofoil. Contributions of this thesis link oscillating foil propulsion research to common marine engineering equations with the intent of making flapping wing propeller design more accessible to the general engineering community.

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Revisa os métodos para cálculo de desempenho e ruído de hélices. Apresenta um método para determinação de desempenho de hélices com mínima perda de energia usando a teoria dos vórtices. Faz uso das tabelas de Goldstein que criam automaticamente a geometria da hélice através do acesso a um banco de dados aerodinâmico. Avalia o ruído harmônico com o método no domínio da freqüência, utilizando os valores de desempenho e geometria previamente calculados. Valida o método de desempenho e ruído através da comparação com dados experimentais. Apresenta um estudo de caso para desempenho e ruído de hélices aplicados a ultraleves e aviação geral e compara as diferentes configurações e seus efeitos no desempenho e ruído. Conclui que a simplicidade de implantação do método o torna indicado para o projeto preliminar e permite que seja integrado com modelos de otimização. / This paper reviews the methods of propeller performance and noise calculation. It presents a prediction method for propellers performance with minimum energy loss. The method uses the vortex theory, using the Goldstein circulation function tables for performance determination, linked with an aerodynamic database for propeller geometry generation. The results are used for a quick evaluation of propeller harmonic noise through the frequency domain method. The method is validated by comparison with experimental data. It presents a case study of propeller designed for a very light aircraft, comparing different configurations and its effects on performance and noise. The method is recommended in the framework of preliminary design and for integration with optimization algorithms.

In the development of underwater vehicles, it is necessary to conduct performance test in the water tank. However, different factors need to be considered depending on different cases. The purpose of this paper is to construct a simulation platform in the air to study the scenarios like side current or constant height profiling. Although these tests are difficult to be performed in the water tank, we can get some solutions from observing the dynamics of simulation platform. The simulation platform we used consists of three links to constraint the motion in a polar coordinate system. It carries a wireless micro-camera, and two DC motor-driven propellers. At the end of the distal link and metal disk is attached on the other side of the pivot of the last link to provide counter-weight which can simulate different status of the "buoyancy" of the platform. The encoder which is uses to trace the motion of the simulation platform, is mounted at each join between two links. The control program has two parts: servo control of propellers and target tracking. In order to approach to the real-time searching, we derived image with gray scale instead of color form to increase image refreshing rate during the tracking process. For the current experiment, the target is at dot generated by an LED. The location of the bright dot is detected by a histogram-based threshold, and the actual location is further refined with intensity-weighted algorithm. The offset between of the target and the center of the image is used as the feedback to command the propellers to drive the platform. The goal is to keep the target at the center of the image as close as possible. A linear PD control (proportional - derivative) is implemented to drive the propellers. Preliminary experiments show that the simulation platform can track a target with about 15 frames per second refreshing rate under the condition that the target does not move too fast and vanishes in the image. When ROV with laser scanner syetem, seafloor away from ROV's accuracy is necessary. In this eassay, we use tracking angle and tracking bright dot to qualify and quantify the influence of buoyancy and propeller on the altitude control in different cases.

Denna rapport utgör det avslutande momentet på programmet Produktutveckling 180hp vid Blekinge Tekniska Höskola. Rapporten kommer behandla framtagning av en nykonstruktion för fixturering av propellerblad i en bearbetningsmaskin. Arbetet hart gjorts i samarbete med företaget Xylem Water Solutions Manufacturing AB i Lindås. Arbetet har mynnat ut i ett konceptförslag och en rapport som projektgruppen för inköp och uppstart av den nya maskinen kommer kunna ta del av och använda som underlag vid detaljkonstruktionen av den faktiska fixturen som kommer tillverkas. Den största delen i detta arbetet har lagts på alla de steg som har varit nödvändiga att göra för att kunna komma fram till slutresultatet. Möten, intervjuer, dialoger med handledare, operatörer och tekniker för att ta del av tips och åsikter för att kunna ta fram ett fungerande koncept. / This report constitutes the final step at the program Product Development 180hp at Blekinge Institute of Technology. The report will include development of a new design for fixturing propeller blades in a processing machine. The project has taken place in cooperation with the company Xylem Water Soloutions Manufacturing AB in Lindås. The work has come to a proposal for a concept and a report that the project group for purchasing and start-up of the new machine cantake part of and will be able to use as a foundation for the actual fixture that will be manufactured. The biggest part of this project has been with all the necessary work done researching to be able to come up with the final result. Meetings, interviews, dialogue with mentor, operators and technicians to take part of their feedback and opinions required to make a functional concept.