Numerous hydrodynamic theories may be used to predict the performance of marine propellers. The goal of this thesis is to investigate and implement a lifting line theory as a program written in FORTRAN and to test its capabilities on some Wageningen B-Series propellers. Special attention is given to the validation of the routines involved in the implementation of the theory. Difficulties were experienced in obtaining results that accurately reflect the published experimental results, and some discussion is included regarding possibilities for the sources of these errors. Also discussed are the results of other lifting line codes and their respective differences from the current implementation.

This work focuses on the development of efficient methods for wing shape optimization for morphing wing technologies. Existing wing shape optimization processes typically rely on computational fluid dynamics tools for aerodynamic analysis, but the computational cost of these tools makes optimization of all but the most basic problems intractable. In this work, we present a set of tools that can be used to efficiently explore the design spaces of morphing wings without reducing the fidelity of the results significantly. Specifically, this work discusses automatic differentiation of an aerodynamic analysis tool based on lifting line theory, a light-weight gradient-based optimization framework that provides a parallel function evaluation capability not found in similar frameworks, and a modification to the lifting line equations that makes the analysis method and optimization process suitable to wings of arbitrary aspect ratio. The toolset discussed is applied to several wing shape optimization problems. Additionally, a method for visualizing the design space of a morphing wing using this toolset is presented. As a result of this work, a light-weight wing shape optimization method is available for analysis of morphing wing designs that reduces the computational cost by several orders of magnitude over traditional methods without significantly reducing the accuracy of the results.

An analytical investigation was conducted to study the behavior of a bottom flange bearing beam-to girder connection subjected to patch loading. This connection would be useful with deep deck (thickness greater than 3 in.) composite slabs as well as with commonly used deck where floor-to-floor height needs to be minimized. Five girder specimens were loaded until yielding during the initial phase of the research. The analysis section consists of the yield line theory and finite element study that were used to develop a model to predict the collapse loads of the girder sections. These results from the model were then compared to the experimental loads. A design procedure utilizing the proposed model and future work recommendations are then presented. / Master of Science

Este trabalho apresenta uma associação dos cálculos elástico e plástico, para lajes retangulares com carga uniforme e uma borda livre. O cálculo elástico é usado para pré-dimensionamento, na determinação dos momentos negativos e da razão dos momentos positivos nas duas direções. Esses momentos fletores são obtidos através de funções aproximadoras, determinadas a partir de tabelas. Após compatibilização dos momentos elásticos, são adotados os momentos de plastificação negativos, sendo os positivos obtidos através da teoria das chameiras plásticas, que é utilizada também no cálculo do comprimento das barras sobre os apoios. Conhecidas as armaduras, os momentos elásticos são novamente utilizados na verificação das flechas. Nos exemplos são comparadas as armaduras do cálculo elástico com as obtidas através do cálculo plástico, no qual se pôde constatar a economia deste último em relação ao primeiro. / This work presents an association of elastic and plastic analysis, for rectangular slabs with uniform load and a free edge. The elatic theory is used to estimate the negative moments and the relation between positive moments in the two directions. These bending moments are obtained from approached functions, based on tables. After compatibilization of elastic moments, the negative plastic moments are adopted and the positive moments are obtained from yield line theory, which will be used again in the calculation of the lenght of the bars over the supports. Once the reinforcements are known, the elastic moments are used again for checking the deflexions. In the examples, the results of elastic plate theory are compared with those obtained by plastic analysis, where it is possible to evidence the economy of the later over the former.

Computational fluid dynamics (CFD) analysis was performed in order to compare the solutions of oscillating wings with Prandtl’s lifting-line theory. Quasi-steady and steady-periodic simulations were completed using the CFD software Star-CCM+. The simulations were performed for a number of frequencies in a pure plunging setup. Additional simulations were then completed using a setup of combined pitching and plunging at multiple frequencies. Results from the CFD simulations were compared to the quasi-steady lifting-line solution in the form of the axial-force, normal-force, power, and thrust coefficients, as well as the efficiency obtained for each simulation. The mean values were evaluated for each simulation and compared to the quasi-steady lifting-line solution. It was found that as the frequency of oscillation increased, the quasi-steady lifting-line solution was decreasingly accurate in predicting solutions.

Throughout the United States accelerated bridge construction is becoming increasingly popular to meet growing transportation demands while keeping construction time and costs to a minimum. This research focuses on eliminating the need to form full-depth concrete bridge deck overhangs, accelerating the construction of concrete bridge decks, by using full-depth precast prestressed concrete deck panels. Full-depth precast overhang panels in combination with cast-in-place (CIP) reinforced concrete are experimentally and analytically investigated to assess the structural performance. Experimental loaddeformation behavior for factored AASHTO LRFD design load limits is examined followed by the collapse capacity of the panel-to-panel seam that exists in the system. Adequate strength and stiffness of the proposed full-depth panels deem the design safe for implementation for the Rock Creek Bridge in Fort Worth, Texas. New failure theories are derived for interior and exterior bridge deck spans as present code-based predictions provide poor estimates of the ultimate capacity. A compound shear-flexure failure occurs at interior bays between the CIP topping and stay-in-place (SIP) panel. Overhang failure loads are characterized as a mixed failure of flexure on the loaded panel and shear at the panel-to-panel seam. Based on these results design recommendations are presented to optimize the reinforcing steel layout used in concrete bridge decks.

Este trabalho apresenta uma associação dos cálculos elástico e plástico, para lajes retangulares com carga uniforme e uma borda livre. O cálculo elástico é usado para pré-dimensionamento, na determinação dos momentos negativos e da razão dos momentos positivos nas duas direções. Esses momentos fletores são obtidos através de funções aproximadoras, determinadas a partir de tabelas. Após compatibilização dos momentos elásticos, são adotados os momentos de plastificação negativos, sendo os positivos obtidos através da teoria das chameiras plásticas, que é utilizada também no cálculo do comprimento das barras sobre os apoios. Conhecidas as armaduras, os momentos elásticos são novamente utilizados na verificação das flechas. Nos exemplos são comparadas as armaduras do cálculo elástico com as obtidas através do cálculo plástico, no qual se pôde constatar a economia deste último em relação ao primeiro. / This work presents an association of elastic and plastic analysis, for rectangular slabs with uniform load and a free edge. The elatic theory is used to estimate the negative moments and the relation between positive moments in the two directions. These bending moments are obtained from approached functions, based on tables. After compatibilization of elastic moments, the negative plastic moments are adopted and the positive moments are obtained from yield line theory, which will be used again in the calculation of the lenght of the bars over the supports. Once the reinforcements are known, the elastic moments are used again for checking the deflexions. In the examples, the results of elastic plate theory are compared with those obtained by plastic analysis, where it is possible to evidence the economy of the later over the former.

This master thesis shows, how can be the modified lifting line theory used for preliminary glider design an for wing loads determination. It is shown, that relatively accurate results can be obtained at less computational cost in comparison with CFD methods

The FanWing propulsion system is a novel propulsion system which aerodynamically behaves as a hybrid between a helicopter and a fixed wing aircraft, and if the knowledge base with regards to this novel concept can be fully explored, there could be a new class of aircraft developed. In the current research, only 2D CFD studies have been done for the FanWing, hence the 3D lift characteristics of the FanWing have been unknown thus far, at least in the theoretical domain. Therefore, it was proposed to develop a modified Prandtl's Lifting Line Theory numerical solution and a CFD solution, comparing the results of each. A new variable was introduced into the classical Lifting Line Theory solution, αi,FW, to account for the additional lift produced by the FanWing as opposed to a traditional airfoil. This variable, αi,FW, is a function of the wing angle and the velocities taken at three-quarter chord length on the FanWing. The introduction of this variable was informed by other papers which superimposed velocities when developing Lifting Line Theory for unconventional airfoil planforms. After introducing a correction factor, the numerical model aligned with the 3D CFD results where LLT assumptions were valid. For the 3D simulation, it was observed that the lift per unit span rapidly increases from quarter span to wingtip, which is different from traditional wing planforms. This study provides a valuable first step towards documenting the 3D lift characteristics of the novel FanWing propulsion system.

A combined wing and propeller model is presented as a low-cost approach to preliminary modeling of slipstream effects on a finite wing. The wing aerodynamic model employs a numerical lifting-line method utilizing the 3D vortex lifting law along with known 2D airfoil data to predict the lift distribution across a wing for a prescribed upstream flowfield. The propeller/slipstream model uses blade element theory combined with momentum conservation equations. This model is expected to be of significant importance in the design of tail-sitter vertical take-off and landing (VTOL) aircraft, where the propeller slipstream is the primary source of air flow past the wings in some flight conditions. The algorithm is presented, and results compared with published experimental data.