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Full-Text Articles in Engineering
A General Approach To Lifting-Line Theory, Applied To Wings With Sweep, Jackson T. Reid
A General Approach To Lifting-Line Theory, Applied To Wings With Sweep, Jackson T. Reid
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Lifting-line theory is one simple method of predicting the lift produced by a wing. The traditional implementation of lifting-line theory, developed in 1918, is limited to predicting the lift of traditional straight wings. In this work, lifting-line theory is extended to predict the lift produced by modern swept (or "v-shaped") wings by strategically handling the singularities inherent to the theory. The resulting formulation is shown to be both accurate and computationally inexpensive, when compared to experimental and higher-fidelity computational results, demonstrating the method's usefulness as an aerodynamic design tool. Because of the low computational cost and accuracy of the method …
Optimization Of A Low Reynold's Number 2-D Inflatable Airfoil Section, Todd A. Johansen
Optimization Of A Low Reynold's Number 2-D Inflatable Airfoil Section, Todd A. Johansen
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A stand-alone genetic algorithm (GA) and an surrogate-based optimization (SBO) combined with a GA were compared for accuracy and performance. Comparisons took place using the Ackley Function and Rastrigin's Function, two functions with multiple local maxima and minima that could cause problems for more traditional optimization methods, such as a gradient-based method. The GA and SBO with GA were applied to the functions through a fortran interface and it was found that the SBO could use the same number of function evaluations as the GA and achieve at least 5 orders of magnitude greater accuracy through the use of surrogate …