An Investigation Of Avian Wing Tip Vortex Generation Using A Biomimetic Approach,
2017
California Polytechnic State University, San Luis Obispo
An Investigation Of Avian Wing Tip Vortex Generation Using A Biomimetic Approach, David Stewart Martin
Master's Theses
An experimental study has been conducted to develop a process allowing the creation of biologically accurate aerodynamic test models mimicking the slotted primary feather geometry of the Brown Pelican (Pelecanus occidentalis). Preserved examples of both a full Brown Pelican wing and a single primary feather were 3D scanned and digitally reconstructed using a combination of MATLAB and CAD software. The final model was then 3D printed as a collection of smaller components using a LulzBot TAZ 6 printer and Taulman3D T-Glase PET filament. After using various surface finishing techniques to improve the finish of all 3D printed parts, …
Aerodynamics And Vortex Structures Of A Flapping Airfoil In Forward Flight In Proximity Of Ground,
2017
Washington University in St. Louis
Aerodynamics And Vortex Structures Of A Flapping Airfoil In Forward Flight In Proximity Of Ground, Hang Li
McKelvey School of Engineering Graduate Student Theses & Dissertations
The traditional flapping wing high lift mechanism research mainly focuses on the wing in unbounded flow. However, the real insect flight includes not only the unbounded flow field but also the near-surface flight. Therefore, research on near-surface flight can help reveal the high-lift mechanism of insect flight and should also be beneficial to the research on Micro-Air-Vehicles (MAV). In this thesis, the flow fields of an airfoil in hover and forward flight are simulated in the presence of ground by newly available function of “dynamic meshing” in ANSYS Fluent is employed. The characteristics of aerodynamics, pressure distribution, and vortex structure …
Aerodynamics And Shock Buffet Of A Transonic Airfoil In Ground Effect,
2017
Washington University in St. Louis
Aerodynamics And Shock Buffet Of A Transonic Airfoil In Ground Effect, Boshun Gao
McKelvey School of Engineering Graduate Student Theses & Dissertations
No abstract provided.
Design And Computational Fluid Dynamics Analysis Of An Idealized Modern Wingsuit,
2017
Washington University in St. Louis
Design And Computational Fluid Dynamics Analysis Of An Idealized Modern Wingsuit, Maria E. Ferguson
McKelvey School of Engineering Graduate Student Theses & Dissertations
The aerodynamics of a modern wingsuit has been the subject of very few detailed scientific studies to date. The prevailing design process remains the dangerous “sew and fly” method, in which designs are tested when they are first flown. This study utilizes Computational Fluid Dynamics (CFD) tools to analyze the flow field and aerodynamics of an idealized wingsuit, which is designed using Computer-Aided Design (CAD) modeling. The 3D CAD software Autodesk Inventor is used to create the wingsuit model, which is designed with a Gottingen 228 airfoil cross-section and a relatively large planform of aspect ratio 1.3. The commercial flow …
Uncertainty Quantification Of Turbulence Model Closure Coefficients On Openfoam And Fluent For Mildly Separated Flows,
2017
Washington University in St. Louis
Uncertainty Quantification Of Turbulence Model Closure Coefficients On Openfoam And Fluent For Mildly Separated Flows, Ike Witte
McKelvey School of Engineering Graduate Student Theses & Dissertations
In this thesis, detailed uncertainty quantification studies focusing on the closure coefficients of eddy-viscosity turbulence models for several flows using two CFD solvers have been performed. Three eddy viscosity turbulence models considered are: the one-equation Spalart-Allmaras (SA) model, the two-equation Shear Stress Transport (SST) k-ω model, and the one-equation Wray-Agarwal (WA) model. OpenFOAM and ANSYS Fluent are used as flow solvers. Uncertainty quantification analyses are performed for subsonic flow over a flat plate, subsonic flow over a backward-facing step, and transonic flow past an axisymmetric bump. In the case of flat plate, coefficients of pressure, lift, drag, and skin friction …
Numerical Study Of The Aerodynamics Of Dlr-F6 Wing-Body In Unbounded Flow Field And In Ground Effect,
2017
Washington University in St. Louis
Numerical Study Of The Aerodynamics Of Dlr-F6 Wing-Body In Unbounded Flow Field And In Ground Effect, Ning Deng
McKelvey School of Engineering Graduate Student Theses & Dissertations
The main focus of this thesis is on the simulation of flow past a three-dimensional wing-body configuration (DLR-F6) in ground effect; a complex 3D wing-body configuration in ground effect has never been analyzed in the aerodynamics literature to date. For the purpose of validation of the simulation approach, computations are performed for the DLR-F6 wing-body in unbounded flow and are compared with the experimental data. The commercial CFD solver ANSYS FLUENT is employed for computations. Compressible Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with Spalart-Allmaras (SA) and - Shear Stress Transport (SST) turbulence models are solved. The validated code is employed …
Literature Review: Biomimetic And Conventional Aircraft Wing Tips,
2017
International Islamic University - Malaysia
Literature Review: Biomimetic And Conventional Aircraft Wing Tips, Naseeb Ahmed Siddiqui, Waqar Asrar, Erwin Sulaeman
International Journal of Aviation, Aeronautics, and Aerospace
This paper is an attempt to summarize the effect of wing tip devices employed by birds, as well as aeronautical engineers in the past to improve the performance characteristics of aircraft. The focus is on reduction of the induced drag or drag due to lift also known as inviscid drag. This paper will provide an insight on both biomimetic and conventional wing tip approaches to reduce the induced drag. Prior analysis and experiments on the aerodynamics of airplane performance due to both these separate studies have been discussed. The needs of the industry and their past inventions have been described …
Application Of Strand-Cartesian Interfaced Solver On Flows Around Various Geometries,
2017
Utah State University
Application Of Strand-Cartesian Interfaced Solver On Flows Around Various Geometries, Yushi Yanagita
All Graduate Plan B and other Reports, Spring 1920 to Spring 2023
This work examines the application of a high-order numerical method to strand-based grids to solve the Navier-Stokes equations. Coined "Flux Correction", this method eliminates error terms in the fluxes of traditional second-order finite volume Galerkin methods. Flux Correction is first examined for applications to the Reynolds-Averaged Navier-Stokes equations to compute turbulent flows on a strictly strand-based domain. Flow over three geometries are examined to demonstrate the method’s capabilities: a three-dimensional bump, an infinite wing, and a hemisphere-cylinder configuration. Comparison to results obtained from established codes show that the turbulent Flux Correction scheme accurately predicts flow properties such as pressure, velocity …
Comparison Of Rans Modeling To Dual-Plane Piv Measurements Of The Turbulent Tip Vortex Trailed From A Hovering Rotor,
2017
Embry-Riddle Aeronautical University
Comparison Of Rans Modeling To Dual-Plane Piv Measurements Of The Turbulent Tip Vortex Trailed From A Hovering Rotor, Zachary Lietzau
Doctoral Dissertations and Master's Theses
Numerical simulations using the Reynolds-Averaged Navier-Stokes (RANS) equations were conducted to study the development and turbulent decay of the tip vortices in the wake produced by a hovering rotor. The computational results were compared to detailed, dual plane Particle Image Velocimetry (PIV) measurements of a turbulent tip vortex trailed from a single-bladed rotor. The work investigated both the required mesh resolution and most suitable turbulence closure models with rotational/curvature corrections by assessing their predictions of the tip vortex properties and the overall physical nature of the rotor wake. It was found that even when using a higher-order accurate central differencing …
Extended Surface Heat Transfer Coefficients Via Endwall Temperature Measurements,
2017
Embry-Riddle Aeronautical University
Extended Surface Heat Transfer Coefficients Via Endwall Temperature Measurements, Yogesh Pai
Doctoral Dissertations and Master's Theses
Short pins are used for internal cooling of the trailing edge in a gas turbine blade. A novel method is described in this thesis which helps in simplifying the experimental process used to obtain average heat transfer data on the pin surface, at the expense of additional post processing complexity. The method is based on a unique, analytical solution of the longitudinal conduction equation with internal heat generation, allowing computation of heat transfer rates via pin base temperature measurements via Temperature Sensitive Paint, or similar non-intrusive methods. Verification of this method is done with comparisons to the solution of infinite …
A Performance And Visualization Study On Inlet Geometries Of A Cross-Flow Fan.,
2017
University of Louisville
A Performance And Visualization Study On Inlet Geometries Of A Cross-Flow Fan., Yoel Tanquero
Electronic Theses and Dissertations
A study was conducted to characterize the flow-field in the suction region of different inlet geometries of a cross-flow fan. The characterization was accomplished by correlating the static performance curves measured for each fan-inlet configuration to the streamline plot obtained using a particle tracking velocimetry (PTV) measurement system at three constant flow rates (25, 40, and 55 CFM). The PTV measurement system used was developed by the author and uses helium bubbles as tracers, an LED light sheet, a slow motion camera, and a Matlab program. Four inlet geometry design variables were defined and independently studied to evaluate the effect …
Actuator Disk Theory For Compressible Flow,
2017
California Polytechnic State University, San Luis Obispo
Actuator Disk Theory For Compressible Flow, Htet Htet Nwe Oo
Master's Theses
Because compressibility effects arise in real applications of propellers and turbines, the Actuator Disk Theory or Froude’s Momentum Theory was established for compressible, subsonic flow using the three laws of conservation and isentropic thermodynamics. The compressible Actuator Disk Theory was established for the unducted (bare) and ducted cases in which the disk was treated as the only assembly within the flow stream in the bare case and enclosed by a duct having a constant cross-sectional area equal to the disk area in the ducted case. The primary motivation of the current thesis was to predict the ideal performance of a …
Investigation Of Dynamic Store Separation Out Of A Weapons Bay Cavity Utilizing A Low Speed Wind Tunnel,
2017
Air Force Institute of Technology
Investigation Of Dynamic Store Separation Out Of A Weapons Bay Cavity Utilizing A Low Speed Wind Tunnel, Andrew D. Bower
Theses and Dissertations
Characterizing mission store trajectories as they separate from a weapons bay cavity is highly relevant to the Air Force mission. The flow around a weapons bay is unsteady. The unsteady flow can cause a mission store separation trajectory to be unpredictable, and such is the case for what some have termed a pitch bifurcation. Traditional wind tunnel testing is incapable of detecting a bifurcation because traditional wind tunnel testing records time-averaged data. In this study, an experimental testing system was developed and refined in order to support the time-accurate characterization of dynamic mission store separation events. A Motion Test Apparatus …
Time-Dependent Validation Of Finite Element Strain Distribution Of A Plastically-Deformed Plate Via Digital Image Correlation,
2017
Air Force Institute of Technology
Time-Dependent Validation Of Finite Element Strain Distribution Of A Plastically-Deformed Plate Via Digital Image Correlation, Kevin R. Knapp
Theses and Dissertations
Generation of residual stress is an essential step in the generation of Goodman data via Air Force Research Laboratory's vibration-based fatigue test. Conventional Goodman data is constructed through uniaxial fatigue testing at a rate of 40 Hz, while the vibration-based testing excites stresses at 1,600 Hz in a stress state that is similar to those seen in gas turbine engine airfoils. A pre-strain procedure is conducted to form residual tensile stress, which serves as a steady stress when the specimen is subjected to fully-reversed vibration-based fatigue loads. This steady tensile stress is desired at the fatigue zone of the test …
In-House Fabrication Of Temperature Sensitive Paint For Turbine Cooling Research,
2017
Embry-Riddle Aeronautical University
In-House Fabrication Of Temperature Sensitive Paint For Turbine Cooling Research, Mayur D. Patel, Mark A. Ricklick
Beyond: Undergraduate Research Journal
The Temperature Sensitive Paint (TSP) is a widely used method in measuring and visualizing flow separation and heat transfer. Compared to the cost and time consumption needed for methods such as pitot tubes, temperature sensitive paint is a cheaper alternative. Due to high usage in College of Engineering research projects, it was determined that in house fabrication of temperature sensitive paint would reduce time and cost limitations. For initial stages, literature research was performed to determine the recipe of intensity based TSP with luminophore and polymer binder that operated optimum at temperatures from 0-100°C. Europium III thenoyltrifluoroacetonate was determined to …
An Archival Analysis Of Stall Warning System Effectiveness During Airborne Icing Encounters,
2017
Embry-Riddle Aeronautical University
An Archival Analysis Of Stall Warning System Effectiveness During Airborne Icing Encounters, John Michael Maris
Doctoral Dissertations and Master's Theses
An archival study was conducted to determine the influence of stall warning system performance on aircrew decision-making outcomes during airborne icing encounters. A Conservative Icing Response Bias (CIRB) model was developed to explain the historical variability in aircrew performance in the face of airframe icing. The model combined Bayes’ Theorem with Signal Detection Theory (SDT) concepts to yield testable predictions that were evaluated using a Binary Logistic Regression (BLR) multivariate technique applied to two archives: the NASA Aviation Safety Reporting System (ASRS) incident database, and the National Transportation Safety Board (NTSB) accident databases, both covering the period January 1, 1988 …
Rans Simulations Of Aerodynamic Performance Of Naca 0015 Flapped Airfoil,
2017
Rowan University
Rans Simulations Of Aerodynamic Performance Of Naca 0015 Flapped Airfoil, Sohaib Obeid, Ratneshwar Jha, Goodarz Ahmadi
Henry M. Rowan College of Engineering Departmental Research
An analysis of 2D subsonic flow over an NACA 0015 airfoil with a 30% trailing edge flap at a constant Reynolds number of 106 for various incidence angles and a range of flap deflections is presented. The steady-state governing equations of continuity and momentum conservation are solved combined with the realizable k-ε turbulence model using the ANSYS-Fluent code (Version 13.7, ANSYS, Inc., Canonsburg, PA, USA). The primary objective of the study is to provide a comprehensive understanding of flow characteristics around the NACA 0015 airfoil as a function of the angle of attack and flap deflection at Re = 106 …
Multi-Stage Axial Compressor With Counter-Rotation,
2017
Embry-Riddle Aeronautical University
Multi-Stage Axial Compressor With Counter-Rotation, Vinod Gehlot, Magdy S. Attia, Divyam Garg
Publications
A multi-stage axial compressor incorporating a counter-rotational movement is provided with a series of rotors mounted along and driven by a driveshaft, and a geared counter-rotating outer casing. A planetary gear system is assembled along a static casing, which can be assembled as a forward or aft casing for the compressor. The bearings of the planetary gear system typically will be aligned concentrically with a center rotor drum assembly mounted along the single driveshaft. The counter-rotating drum assembly will be assembled over the rotor drum assembly and will be engaged by the forward and aft casings so as to provide …
Characteristics Of Hydrogel-Wetted Thin Films,
2017
University of Central Florida
Characteristics Of Hydrogel-Wetted Thin Films, James Owens
Electronic Theses and Dissertations
The meniscus region of a thin film is known to have high heat transfer properties due to high evaporation rates and activation of latent heat. The region known as the thin film meniscus (δfilm lt& 2 µm ) can account for more than half of the total heat transfer of a droplet or film. This study focuses on the potential elongation and curvature amplification of the thin film meniscus region by the implementation of a layer of high hydrogen bonding (hydrogel) film on which the liquid meniscus is built. Forced wetting via liquid propagation though this hydrogel layer in the …
Mid-Infrared Absorption Spectrometer For Multi-Species Detection Using Leds For Space Applications: Development And Flight Testing,
2017
University of Central Florida
Mid-Infrared Absorption Spectrometer For Multi-Species Detection Using Leds For Space Applications: Development And Flight Testing, Michael Villar
Electronic Theses and Dissertations
As commercial space travel expands, the need for specialized instrumentation to ensure the safety of crew and cargo becomes increasingly necessary. Both the Federal Aviation Administration (FAA) and pioneers in the space tourism industry have expressed an interest in a robust, low cost, and low power consumption sensor to measure atmospheric composition aboard spacecraft. To achieve this goal a time-resolved NDIR absorption sensor that measures transient levels of gaseous carbon dioxide (CO2) and carbon monoxide (CO) was developed. The developed sensor has a wide range of applications applicable to the growing needs of industry, from monitoring CO and CO2 levels …
