Aerodynamics and Fluid Mechanics Commons^™

Fuel Flow Reduction Impact Analysis Of Drag Reducing Film Applied To Aircraft Wings, Damon Resnick, Chris Donlan, Nimish Sakalle, Cody Pinkerman

SMU Data Science Review

In this paper, we present an analysis of flight data in order to determine whether the application of the Edge Aerodynamix Conformal Vortex Generator (CVG), applied to the wings of aircraft, reduces fuel flow during cruising conditions of flight. The CVG is a special treatment and film applied to the wings of an aircraft to protect the wings and reduce the non-laminar flow of air around the wings during flight. It is thought that by reducing the non-laminar flow or vortices around and directly behind the wings that an aircraft will move more smoothly through the air and provide a …

Design And Performance Estimation Of A Low-Reynolds Number Unmanned Aircraft System, Sean Lauderdale King

LSU Master's Theses

The purpose of this thesis is to conceptually design a fixed-wing unmanned aircraft systems (UAS) with a higher flight-time and top stable speed than comparable systems. The vehicle adheres to specifications derived from the client, the market, and the Federal Aviation Administration (FAA). To broadly meet these requirements, the vehicle must fly for a minimum of three hours, return to the original flight path quickly if perturbed, and must be hand-launched. The vehicle designed must also have a large potential center of gravity movement to allow for customization of the planform and client customization.

An iterative design process was used …

Electro-Drop Bouncing In Low-Gravity, Erin Stivers Schmidt

Dissertations and Theses

We investigate the dynamics of spontaneous jumps of water drops from electrically charged superhydrophobic dielectric substrates during a sudden step reduction in gravity level. In the brief free-fall environment of a drop tower, with a non-homogeneous external electric field arising due to dielectric surface charges (with surface potentials 0.4-1.8 kV), body forces acting on the jumped drops are primarily supplied by polarization stress and Coulombic attraction instead of gravity. This electric body force leads to a drop bouncing behavior similar to well-known phenomena in 1-g₀, though occurring for much larger drops (~0.5 mL). We show a simple …

A Computational Fluid Dynamics Study On The Aerodynamic Performance Of Ram-Air Parachutes, Angelo A. Fonseca Pazmiño

Doctoral Dissertations and Master's Theses

The modeling of a ram-air parachute presents challenges in the prediction of the inflight geometry, as there is a strong interaction between the flow field and parachute structure. This thesis presents the development of a CAD design and CFD methodology to the simulation of ram-air parachutes in steady-state conditions. Starting from a 2D rib drawing, methods were developed to approximate the 3D geometry and efficiently model the parachute as a rigid and impermeable body. The use of distortions was implemented on a 2D, pseudo-2D, and 3D model to enhance their behavior during a real flight. The SST turbulence model was …

A Computational Analysis Of The Aerodynamics And Aeroacoustics Of Jets With Fluid Injection, Marco Coderoni

Doctoral Dissertations and Master's Theses

A detailed numerical analysis of fluidic injection as a tool to reduce noise emission is presented here. The noise reduction strategy, developed at the Pennsylvania State University, is based on injectors that blow air into the diverging section of the nozzle to emulate the effect of interior corrugation on the jet plume. The advantage is that the injection can be activated during takeoff and turned o_ during other phases of flight so that performance is not affected. Numerical simulations are performed on a military-style nozzle based on the GE F400-series engines, with a design Mach number of 1:65, for over-expanded …

Aerothermodynamic Analysis Of A Mars Sample Return Earth-Entry Vehicle, Daniel A. Boyd

Mechanical & Aerospace Engineering Theses & Dissertations

Because of the severe quarantine constraints that must be imposed on any returned extraterrestrial samples, the Mars sample return Earth-entry vehicle must remain intact through sample recovery. Vehicles returning on a Mars-Earth trajectory will attain velocities exceeding any that have been experienced by prior space exploration missions, with velocities approaching 14 km/s. Velocities as high as these will encounter significant heating during atmospheric re-entry to Earth.

The purpose of this study has been to systematically investigate the aerothermodynamic challenges that will result from a Mars sample return, Earth-entry vehicle design. The goal was to enable efficient estimation of maximum stagnation …

A Protocol-Based Blended Model For Fluid Mechanics Instruction, John Solomon, Eric Hamilton, Vimal Viswanathan, Chitra Nayak, Firas Akasheh

Faculty Publications, Mechanical Engineering

A personalized and media-rich learning framework called “Knowledge and Curriculum Integration Ecosystem” (KACIE) has been developed and implemented in a junior level fluid mechanics course in Fall 2016 and Spring 2017. This model shares characteristics of blended instruction as well as a flipped classroom, with an overall structure that includes the application of established principles emerging from the learning sciences and from cognitive neuroscience. These principles have taken form in the KACIE model as classroom protocols or written instructions to scaffold and guide teaching and learning by faculty and students respectively. In KACIE, the course has been presented as a …

The Design And Implementation Of A Supersonic Indraft Tube Wind Tunnel For The Demonstration Of Supersonic Flows, Daniel Kenneth Johnson

Master's Theses

Historically, the endeavor of scale testing flight vehicles at supersonic Mach numbers, especially for long durations, has required the development of closed-loop wind tunnels, which are extremely expensive both to build and operate due to the high complexity and incredible power required to drive such a system. The intermittent blowdown wind tunnel, indraft tunnel, and shock tunnel have alleviated many of these cost requirements to some degree, whilst facilitating testing at very high Mach numbers and enthalpies; however, these systems require the handling of gases at pressures and temperatures that can be prohibitive for many university settings. The Ludwieg tube …

Microfluidic Biosensor With Functionalized Gold Nano Particles On Interdigitated Electrodes, Bharath Babu Nunna

Dissertations

The integration of the microfluidics to the biosensor has growing demand with favorable conditions such as reduced processing time and low reagent consumption. The immuno biosensing with the microfluidic platform helped to make the electrochemical biosensing assays portable due to which this sensing mechanism can be easily implemented in point of care devices. The implementation of the biosensing in the microchannels significantly reduces the sample requirement form milli liter (mL) to micro liter (uL), and thus leads to low volume sample requirement during the sensing. The primary factors contributing to the microfluidic biosensors performance are probe immobilization, specific binding and …

A Microresonator-Based Laser Doppler Velocity Sensor For Interplanetary Atmospheric Re-Entry, Benjamin Wise

Mechanical Engineering Research Theses and Dissertations

In this thesis, a laser velocity sensor concept based on optical microresonators is presented and the application to spacecraft atmospheric entry is explored. The concept is based on the measurement of Doppler shift of back-scattered laser light. Specifically, the Doppler shift is detected by observing the whispering gallery optical modes (WGM) of a dielectric microresonator excited by the back scattered light from particulates and gas molecules. The microresonator replaces the typical Fabry-Perot interferometer and CCD camera system, thereby significantly reducing the size and weight of the overall detection system. This thesis presents proof-of-concept results for this measurement approach. The Doppler …

Validation Of Cfd Simulations For Hypersonic Flow Over A Yawed Cone, Julian Cecil

McKelvey School of Engineering Graduate Student Theses & Dissertations

This study aims to numerically simulate the wind tunnel results for hypersonic flow over a circular cone of semi-apex angle of 10 degrees yawed from 0° to 20° using the commercial computational fluid dynamics software ANSYS Fluent. The ANSYS workbench is used to create the 10° semi-apex circular cone with a shock aligned structured mesh of 3.05 million cells surrounding the cone. Simulation boundary conditions for pressure and temperature in the far field correspond to Tracy’s wind tunnel experiment at Cal Tech. The six simulations cases are conducted for yaw angles of 0, 8, 12, 16, 20 and 24 degrees. …

The Drag Coefficient Of Varying Dimple Patterns, James M. Seeley, Michael S. Crosser

Senior Theses

There are many golf balls on the market today with varying dimple sizes, shapes, and distribution. These proprietary differences are all designed to reduce drag on the balls during flight, allowing golfers to hit the ball farther distances. There are limited published studies comparing how varying the dimples affects the reduction of drag. An experiment was developed in which golf balls were pulled through a water tank to measure the drag force acting on each ball. The water was chosen to allow for testing at slower velocities than the typical necessary speeds to cause turbulence for balls traveling in air. …

Measurement Of Forces On A Flapping Wing Micro Aerial Vehicle, Darnisha Crane

Research Horizons Day Posters

No abstract provided.

Experimental Investigation Of A New Spiral Wingtip, Naseeb Ahmed Siddiqui, Mohammed Aldheeb, Waqar Asrar, Erwin Sulaeman

International Journal of Aviation, Aeronautics, and Aerospace

Experiments on the relative merits and demerits of slotted wingtips mimicking a bird’s primary feathers have been performed. The real emargination length of feather tips, their flexibility and curved shapes during cruise are considered in the present study. The experiments were performed at a Reynolds number of 3.7 x 10⁵ on a symmetric flat plate half wing of aspect ratio 3. Lift, drag and pitching moments were measured using a six component aerodynamic balance. Four different shapes inspired by bird primary feathers have been analysed. The rigid curved tip performed the best increasing the L/D ratio by 20%. This …

Wall-Modeled Large Eddy Simulation Of A Three-Dimensional Shock-Boundary Layer Interaction, Nicholas J. Marco

Theses and Dissertations

The direct simulation of turbulent flows is prohibitive at high Reynolds numbers; thus, methods such as RANS and LES are used. However, these methods still require a large number of cells near a solid boundary. To circumvent this issue, a Wall-Modeled Large Eddy Simulation (WM-LES) can be used. Of interest is how these wall models perform in comparison to a Wall-Resolved Large Eddy Simulation (WR-LES) and experimental results of a shock turbulent boundary layer interactions (STBLI) and specifically, whether equilibrium wall models are sufficient to resolve the oscillatory and hence non-equilibrium nature of these flows or whether a non-equilibrium model …

An Efficient Euler Method To Predict Shock Migration On A Straked Delta Wing Design, Dylan N. Hope

Theses and Dissertations

In support of the Air Force Office of Scientific Research, this project sought to identify the significance of nonlinear aerodynamic phenomena in regards to LCO of a straked delta wing design. Previous works include unsteady Navier-Stokes aeroelastic analysis of various wing designs and flight test of F-16 transonic LCO with interest focused on oscillatory SITES behavior. The research presented within this investigation further expanded the understanding of unsteady aerodynamics by performing aeroelastic analysis of a wing oscillated in pitch with an Euler-based, boundary layer coupled numerical method (ZEUS). The wing was tested for a multitude of LCO parameters such as …

Nonlinear Control Of Underactuated And Constrained Systems, Derek Hoffman

Doctoral Dissertations and Master's Theses

It is the purpose of this document to elaborate on the control of systems that are underactuated or otherwise constrained. To do so, local- and global-coordinate formulations are implemented to generate well-defined system dynamics for a multitude of scenarios. These dynamics are shown to lie on manifolds defined by mathematical restrictions, allowing for singularity-free modeling for global considerations. Feed-back controllers by extension share these benefits, facilitating singularity-free control algorithms as a result. Further, unactuated degrees of freedom can be treated as additional constraints, resulting in an embedded manifold upon the original dynamics. A transformation between a provided set of dynamical …

Numerical Simulation Of Heat Transfer And Chemistry In The Wake Behind A Hypersonic Slender Body At Angle Of Attack, Matthew J. Satchell, Jeffrey M. Layng, Robert B. Greendyke

Faculty Publications

The effect of thermal and chemical boundary conditions on the structure and chemical composition of the wake behind a 3D Mach 7 sphere-cone at an angle of attack of 5 degrees and an altitude of roughly 30,000 m is explored. A special emphasis is placed on determining the number density of chemical species which might lead to detection via the electromagnetic spectrum. The use of non-ablating cold-wall, adiabatic, and radiative equilibrium wall boundary conditions are used to simulate extremes in potential thermal protection system designs. Non-ablating, as well as an ablating boundary condition using the “steady-state ablation” assumption to compute …

2018 Oklahoma Research Day Guide Book, Southwestern Oklahoma State University

Oklahoma Research Day Abstracts

This is the 2018 Oklahoma Research Day Guide Book. This book does not contain abstracts.

Aerodynamic Analysis Of Low Speed Wing Design Using Taguchi L9 Orthogonal Array, Kenneth Witcher, Ian Mcandrew, Elena Vishnevskaya

Publications

The study of aerodynamics has been preoccupied with understanding flight at increasing speeds and ultimately supersonic. Today, this pursuit has advanced the science for both Hypersonic and Transonic flight to near Mach 1 supporting economical commercial flight operations. This research presents the data from a Taguchi array on low speed with twin wing designs to establish the design parameters for their use in low speed and high altitude. Also presented is how aerodynamic advantages can be achieved through understanding the interactions of parameters and their use. This is compared to operational effectiveness when applied to remotely piloted aircraft that are …