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Wind Tunnel Measurements And Data Analysis Tutorial, Nihad E. Daidzic

Aviation Department Publications

This tutorial gives details on processing of raw aerodynamic data measured directly in the wind tunnel on airfoils and wings. Also procedures and equations from the lab report are given and demonstrated how to compute geometric characteristics of wings/airfoils and air data. All numeric results are typically rounded to five significant digits.

Numerical Analysis And Spanwise Shape Optimization For Finite Wings Of Arbitrary Aspect Ratio, Joshua D. Hodson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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 …

Flight And Wing Comparison Of Bats In A Cloud And A Dry Forest In Costa Rica, Makali Haines

Student Symposium

The shape, and size of an object’s wings and body can tell you a lot about their aerodynamics and strategies for flight. Some wings are built to be fast and agile while others are slower but more powerful, and there are a lot of factors that go into deciding the best strategy for each situation or location. When you think of this in terms of animals' wings and different habitats one might predict that different habitats contain animals that have different flying strategies. I measured many aspects of Costa Rican bats caught in both the wet and dry forest, then …

Cfd Study Of Aerodynamic Drag Reduction Tool Of A Generic Sports Utility Vehicle (Suv), Samira Ishrat Jahan

Masters Theses

The Sports Utility Vehicle (SUV) has been a popular automobile choice in North America for over 50 years due to its seating and hauling versatility and good towing capacity. This widespread popularity has resulted in manufacturers pushing for increased horsepower and cabin size. Unfortunately, the limiting factor has been fuel economy which is governed by the vehicle aerodynamics. A reduction in aerodynamic drag can result in better fuel economy. The goal of this study is to reduce the aerodynamic drag of a generic SUV and the efficient application of drag reduction devices to control flow separation. An initial study has …

Sensitivity Analysis Of An Airfoil Using Computational Fluid Dynamics, Itay Savion

Thinking Matters Symposium Archive

In fixed wing aircrafts, the variation of lift coefficient with the angle of attack is a major consideration. This project explores the variation of lift force and lift coefficient of an SD2030 airfoil as a function of the angle of attack, Raynolds number, size of the computational domain, length of the wing, and the fluid mesh size. The problem is modeled using the flow simulation (CFD) module of SolidWorks. The outcome of this sensitivity analysis is compared with available experimental data.

Aerodynamic Design Optimization Of A Locomotive Nose Fairing For Reducing Drag, Chad Lamar Stucki

Theses and Dissertations

Rising fuel cost has motivated increased fuel efficiency for freight trains. At cruising speed,the largest contributing factor to the fuel consumption is aerodynamic drag. As a result of stagnationand flow separation on and around lead and trailing cars, the first and last railcars experiencegreater drag than intermediate cars. Accordingly, this work focused on reducing drag on lead locomotivesby designing and optimizing an add-on nose fairing that is feasible for industrial operation.The fairing shape design was performed via computational fluid dynamic (CFD) software.The simulations consisted of two in-line freight locomotives, a stretch of rails on a raised subgrade,a computational domain, and …

Initial Stage Of Fluid-Structure Interaction Of A Celestial Icosahedron Shaped Vacuum Lighter Than Air Vehicle, Dustin P. Graves

Theses and Dissertations

The analysis of a celestial icosahedron geometry is considered as a potential design for a Vacuum Lighter than Air Vehicle (VLTAV). The goal of the analysis is ultimately to understand the initial fluid-structure interaction of the VLTAV and the surrounding airflow. Up to this point, previous research analyzed the celestial icosahedron VLTAV in relation to withstanding a symmetric sea-level pressure applied to the membrane of the structure. This scenario simulates an internal vacuum being applied in the worst-case atmospheric environmental condition. The next step in analysis is to determine the aerodynamic effects of the geometry. The experimental setup for obtaining …

Investigating The Impact Of Taper And Aspect Ratio On A Stalling Wing Using A Corrected Vortex Lattice Method, Ryan Anderson

Undergraduate Honors Theses

The advent of new technologies such as eVTOL vehicles is exciting. The development of fast aerodynamics models incorporating stall is one small step on the road to realizing such concepts by improving the speed of design optimization algorithms. To this end, a modified vortex lattice model was developed based on one reported by dos Santos and Marques [4]. The model was validated against experimental data found in the literature. Making use of its stall capabilities, a sample study was performed to test for any coupling effect between aspect ratio and taper ratio. This was done by calculating the lift curve …

Sweep And Taper Analysis Of Surfboard Fins Using Computational Fluid Dynamics, Brandon James Baldovin

Master's Theses

The research presented here provides a basis for understanding the hydrodynamics of surfboard fin geometries. While there have been select studies on fins there has been little correlation to the shape of the fin and its corresponding hydrodynamic performance. This research analyzes how changing the planform shape of a surfboard fin effects its performance and flow field. This was done by isolating the taper and sweep distribution of a baseline geometry and varying each parameter individually whilst maintaining a constant span and surface area. The baseline surfboard fin was used as a template in Matlab to generate a set of …

A Higher-Order Method Implemented In An Unstructured Panel Code To Model Linearized Supersonic Flows, Jake Daniel Davis

Master's Theses

Since their conception in the 1960s, panel codes have remained a critical tool in the design and development of air vehicles. With continued advancement in computational technologies, today's codes are able to solve flow fields around arbitrary bodies more quickly and with higher fidelity than those that preceded them. Panel codes prove most useful during the conceptual design phase of an air vehicle, allowing engineers to iterate designs, and generate full solutions of the flow field around a vehicle in a matter of seconds to minutes instead of hours to days using traditional CFD methods. There have been relatively few …

Wake Vortex Pair Formation As An Analog For Dust Devil And Tornado Genesis, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

In 1966, meteorologist R.S. Scorer attempted to explain how large-scale oceanic tropical depressions become hurricanes or typhoons. His model was based on the idea that when these large-scale tropical depression structures begin to rotate, mostly due to Coriolis effects, an annular outer portion of that structure changes suddenly to a potential vortex segment, with the same outer radial limit as the low-pressure structure, but with an inner radius that conserves the overall system angular momentum and kinetic energy. By analogy with the "jump" instability describing sudden buckling of a vertical column, this paper shows that his conjecture merits additional consideration. …

Effect Of Yaw Angle On Flow Structure And Cross-Flow Force Around A Circular Cylinder, Ran Wang, Shaohong Cheng, David S.K. Ting

Civil and Environmental Engineering Publications

Flow around an inclined circular cylinder at yaw angles of α = 0°, 30°, 45°, and 60° has been numerically studied using the delayed detached eddy simulation at a Reynolds number of 1.4 × 104. Periodic boundary conditions are utilized to minimize the end effect. The focus is to explore the effect of yaw angle on the flow structure and the spatial distribution of the cross-flow forces. For the normal flow case, the modulation of the span-wise averaged lift force coefficient is found to be related to the unstable shear layer. For the inclined cases, contours of the sectional lift …

Why The Weird Wings? Investigating The Morphology, Function, And Evolution Of Unusual Feathers In Pigeons And Doves (Columbidae), Robert Lawrence Niese

Graduate Student Theses, Dissertations, & Professional Papers

The feathers of the wing that power flight in birds (the remiges) are morphologically constrained by the demands of aerial locomotion, but peculiar morphologies exist in many taxa in spite of these constraints. In the family Columbidae (pigeons and doves) in particular, we found that atypical remex morphologies have evolved dozens of times and occur in over a third of all species in the family. In members of the genus Columbina, we tested the sound-producing abilities of modified P7 feathers and determined that they are sonations that serve a signalling function during flight. In 56 species we identified a highly-attenuated …

Design And Implementation Of Periodic Unsteadiness Generator For Turbine Secondary Flow Studies, Nathan James Fletcher

Browse all Theses and Dissertations

A primary source of periodic unsteadiness in low-pressure turbines is the wakes shed from upstream blade rows due to the relative motion between adjacent stators and rotors. These periodic perturbations can affect boundary layer transition, secondary flow, and loss generation. In particular, for high-lift front-loaded blades, the secondary flowfield is characterized by strong three-dimensional vortical structures. It is important to understand how these flow features respond to periodic disturbances. A novel approach was taken to generate periodic unsteadiness which captures some of the physics of turbomachinery wakes. Using stationary pneumatic devices, pulsed jets were used to generate disturbances characterized by …

Blended Wing Design Considerations For A Next Generation Commercial Aircraft, Jay Abhilash Vora

Browse all Theses and Dissertations

The current aircraft design has not changed significantly in the last few decades. Growing environmental concerns and fuel prices are driving manufacturers to develop unconventional but efficient aircraft configurations. The blended wing body (BWB) configuration provides an alternate and more efficient means of subsonic travel. The BWB aircraft replaces the traditional wings and fuselage with hybrid wing shape where the fuselage and wings have integrated. Major aircraft manufacturers are researching the BWB concept incorporating electric propulsion for civil transport use. In this research a 300 passenger BWB aircraft aerodynamic shape is designed. This aircraft is used to assess the aerodynamic …

Comparison Of Flow Field In The Proximity Of A Single Planar & Wrap-Around Fin, Nayhel Sharma, Palak Saini, Hrishabh Chaudhary, Gurteg Nagi, Rakesh Kumar Dr.

International Journal of Aviation, Aeronautics, and Aerospace

Abstract

This paper analyses the results of the computational analysis between a single planar and a wrap-around fin mounted on a semi-cylindrical body. A free-stream Computational Fluid Dynamics (CFD) model was simulated for both cases in the Mach 0.4-3.0M range at 0°Angle of attack, in which, the behavior of flow around the fin was investigated using a turbulence model of higher order discretization. The post-processing shows all the possible views of the flow dynamics around the fins, as well as the missile body. The aerodynamic drag and the rolling moment characteristics of the planar and the wrap-around fin have been …