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Articles 1 - 15 of 15
Full-Text Articles in Engineering
Airfoil Flow Optimized Control With An Upstream Cylinder, Nicole Steiner
Airfoil Flow Optimized Control With An Upstream Cylinder, Nicole Steiner
Fall Student Research Symposium 2021
The purpose of this research is to optimize the aerodynamic performance of an airfoil with an upstream cylinder by neural network artificial intelligence. The effects of an upstream oscillating cylinder on the aerodynamic performance of an airfoil are also studied. This paper reports the effects oscillating frequency of the cylinder and the Reynolds number on the lift/drag ratio of the airfoil. The frequency has a complicated correlation with the lift/drag ratio, while the Reynolds number is found to have a positive correlation with the lift/drag ratio. The optimized case is found to have a lift/drag ratio of 1.7319, which is …
Entropy-Based Analysis For Application To Highly Compressible Flows, Ethan A. Vogel
Entropy-Based Analysis For Application To Highly Compressible Flows, Ethan A. Vogel
Doctoral Dissertations
Matrix normalizations are a critical component of mathematically rigorous aerodynamics analysis, especially where kinematic and thermodynamic behaviors are of interest. Here, a matrix normalization based around the entropy of a perturbation is derived according to the principles of mathematical entropy analysis and using a general definition of entropy amendable to physical phenomena such as thermal nonequilibrium and caloric and thermal imperfection. This normalization is shown to be closely related to the contemporary Chu energy normalization, expanding the range of validity of that normalization and clarifying the details of its interpretation. This relationship provides a basis for deriving other normalizations. Entropy …
Empirical Modeling Of Tilt-Rotor Aerodynamic Performance, Michael C. Stratton
Empirical Modeling Of Tilt-Rotor Aerodynamic Performance, Michael C. Stratton
Mechanical & Aerospace Engineering Theses & Dissertations
There has been increasing interest into the performance of electric vertical takeoff and landing (eVTOL) aircraft. The propellers used for the eVTOL propulsion systems experience a broad range of aerodynamic conditions, not typically experienced by propellers in forward flight, that includes large incidence angles relative to the oncoming airflow. Formal experiment design and analysis techniques featuring response surface methods were applied to a subscale, tilt-rotor wind tunnel test for three, four, five, and six blade, 16-inch diameter, propeller configurations in support of development of the NASA LA-8 aircraft. Investigation of low-speed performance included a maximum speed of 12 m/s and …
3d-Printed Morphing Wings For Controlling Yaw On Flying-Wing Aircraft, Benjamin C. Moulton
3d-Printed Morphing Wings For Controlling Yaw On Flying-Wing Aircraft, Benjamin C. Moulton
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The flaps on an airplane wing are used to control the aircraft during flight. These flaps traditionally have at most three articulation or hinge points. Recent studies have shown improved flap efficiency using a conformal flap, which deforms following a curved shape. Much of aircraft improvement comes through increasing its efficiency during flight. This efficiency is generally improved by decreasing the drag force on the aircraft. A potential solution to decrease drag is to remove additional lifting surfaces, such as the horizontal and vertical stabilizer ubiquitous on general aviation aircraft. These additional lifting surfaces are used to trim and control …
Integral Boundary Layer Methods In Python, Malachi Joseph Edland
Integral Boundary Layer Methods In Python, Malachi Joseph Edland
Master's Theses
This thesis presents a modern approach to two Integral Boundary Layer methods implemented in the Python programming language. This work is based on two 2D boundary layer methods: Thwaites' method for laminar boundary layer flows and Head's method for turbulent boundary layer flows. Several novel enhancements improve the quality and usability of the results. These improvements include: a common ordinary differential equation (ODE) integration framework that generalizes computational implementations of Integral Boundary Layer methods; the use of a dense output Runge-Kutta ODE solver that allows for querying of simulation results at any point with accuracy to the same order as …
Design And Flight-Path Simulation Of A Dynamic-Soaring Uav, Gladston Joseph
Design And Flight-Path Simulation Of A Dynamic-Soaring Uav, Gladston Joseph
Doctoral Dissertations and Master's Theses
We address the development of a dynamic-soaring capable unmanned aerial vehicle (UAV) optimized for long-duration flight with no on-board power consumption. The UAV’s aerodynamic properties are captured with the integration of variable fidelity aerodynamic analyses. In addition to this, a 6 degree-of-freedom flight simulation environment is designed to include the effects of atmospheric wind conditions. A simple flight control system aids in the development of the dynamic soaring maneuver. A modular design paradigm is adopted for the aircraft dynamics model, which makes it conducive to use the same environment to simulate other aircraft models. Multiple wind-shear models are synthesized to …
Computational Investigation Of Perforated Plate Film Cooling Utilizing Conjugate Heat Transfer, Jonathan Sippel
Computational Investigation Of Perforated Plate Film Cooling Utilizing Conjugate Heat Transfer, Jonathan Sippel
Doctoral Dissertations and Master's Theses
The accuracy of modern state-of-practice computational fluid dynamics approaches in predicting the cooling effectiveness of a perforated plate film-cooling arrangement is evaluated in ANSYS Fluent. A numerical investigation is performed using the Reynolds Averaged Navier Stokes equations and compared to NASA Glenn’s available Turbulent Heat Flux 4 experimental measurements collected as a part of the Transformational Tools and Technologies Project. A multiphysics approach to model heat conduction through the solid geometry is shown to offer significant improvements in wall temperature and film effectiveness prediction accuracy over the standard adiabatic wall approach. Additionally, localized gradient-based grid adaption is analyzed using the …
Plasma Aerodynamics: Experimental Quantification Of The Lift Force Generated On An Airfoil Using Plasma Actuation To Estimate Power Requirements In Small Uav Applications, Getachew Ashenafi
Plasma Aerodynamics: Experimental Quantification Of The Lift Force Generated On An Airfoil Using Plasma Actuation To Estimate Power Requirements In Small Uav Applications, Getachew Ashenafi
UNLV Theses, Dissertations, Professional Papers, and Capstones
This research addressed the amount of electric power required to induce specific changes in lift force using a NACA 2127 airfoil with a chord length of ~28 mm, connected to a micro load cell, in a wind tunnel of 103 square centimeter cross-section. A DBD plasma actuator supplied by a ZVS driven high voltage pulsed DC circuit, operating at a frequency of 17.4 kHz, was utilized for voltages of up to 5000 V. Two configurations of electrode gapping were compared to determine the efficient use of power. The configuration with a gap of ~1 mm between the upstream and downstream …
Sedan Performance/Economy Rear Diffuser, Jacob Boucher Koris
Sedan Performance/Economy Rear Diffuser, Jacob Boucher Koris
Thinking Matters Symposium
This project consists of designing in SolidWorks a model of the performance/fuel economy diffuser. The design is modeled with an Ahmed body (recommended shape for CFD testing vehicles) and the diffuser will be applied to the bottom of the rear bumper of the car. After this is done the model will be imported into ANSYS for CFD testing. Testing entails importing the model, then creating a mesh around the model, and then setting up the program to run analysis for calculating the coefficient of drag. Then building this SolidWorks model as a full working prototype for actual road-testing purposes. With …
State Consistence Of Data-Driven Reduced Order Models For Parametric Aeroelastic Analysis, William C. Krolick, Jung I. Shu, Yi Wang, Kapil Pant
State Consistence Of Data-Driven Reduced Order Models For Parametric Aeroelastic Analysis, William C. Krolick, Jung I. Shu, Yi Wang, Kapil Pant
Faculty Publications
This paper investigates the state consistence of parametric data-driven reduced order models (ROMs) in a state-space form obtained by various system identification methods, including autoregressive exogenous (ARX) and subspace identification (N4SID), for aeroelastic analysis in varying flight conditions. The target flight envelop is first partitioned into discrete grid points, on each of which an aerodynamic ROM is constructed using system identification to capture the dependence of the generalized aerodynamic force on the generalized displacement of structural modes. High-fidelity aeroelastic modal perturbation simulations are used to generate the ROM training and verification data. Aerodynamic ROMs not on the grid point are …
Next-Generation Re-Entry Aerothermodynamic Modeling Of Space Debris Using Machine Learning, Nicholas Sia
Next-Generation Re-Entry Aerothermodynamic Modeling Of Space Debris Using Machine Learning, Nicholas Sia
Graduate Theses, Dissertations, and Problem Reports
The number of resident space objects re-entering the atmosphere is expected to rise with increased space activity over recent years and future projections. Predicting the survival and impact location of the medium to large sized re-entering objects becomes important as they can cause on ground casualties and damage to property. Uncertainties associated with the re-entry process makes necessary a probabilistic approach, which can be computationally expensive when using high-fidelity numerical methods for estimating aerothermodynamic properties. To date, object-oriented analysis is the dominant tool used for atmospheric re-entry modeling and simulation, where aerothermodynamic coefficients are used to determine the risk a …
Identification Of Wind-Induced Hazard Zones Impacting Uas Bridge Inspection, Jack J. Green, John Mott
Identification Of Wind-Induced Hazard Zones Impacting Uas Bridge Inspection, Jack J. Green, John Mott
International Journal of Aviation, Aeronautics, and Aerospace
Unmanned Aerial Systems (UAS) continue to grow in both popularity and utility within the national airspace system. The use of commercial UAS for civil inspection, specifically that of bridge structures, is becoming commonplace among practitioners and academics alike. The development of an integrated bridge-inspection hazard model provides a way for UAS operators to prepare for and respond to changing environmental conditions that could otherwise prevent a successful UAS flight. The interaction of wind-induced airflow with bridge surfaces creates an aerodynamic wake that can result in hazardous conditions for a UAS platform operating in close proximity. An analysis of this airflow …
Bicycle Wheel Aerodynamics Predictions Using Cfd: Efficiency Using Blade Element Method, Drew Vigne
Bicycle Wheel Aerodynamics Predictions Using Cfd: Efficiency Using Blade Element Method, Drew Vigne
Honors Undergraduate Theses
The cycling industry has long relied on expensive wind tunnel testing when designing aerodynamic products, particularly in the context of wheels which account for 10 to 15 percent of a cyclist's total aerodynamic drag. With the recent advent of Computational Fluid Dynamics (CFD), the industry now has an economical tool to supplement the wheel design process; however, the complex nature of rotating spoked wheels requires high resolution meshes to model at acceptable fidelity. This research investigates an alternative CFD method that lowers the computational cost of modeling aerodynamic bicycle wheels by modeling spokes using Blade Element Method (BEM). Two CFD …
Convective Heat Transfer Enhancement Of A Channel-Flow Using Horizontally-Oriented Piezoelectric Fans, Janak Tiwari
Convective Heat Transfer Enhancement Of A Channel-Flow Using Horizontally-Oriented Piezoelectric Fans, Janak Tiwari
Electronic Theses and Dissertations
Experimental and numerical studies were carried out to investigate the convection heat transfer enhancement of air channel flow using a piezoelectric fan, operated at 90.3 Hz. Its peak-to-peak displacement was increased up to 11.8 mm. The average velocity of channel flow was ranged up to 3 m/s, covering both laminar and turbulent flow regimes. The effects of fan location on the heat transfer performance were evaluated by changing the relative position of the fan tip to the heated surface. A maximum heat transfer enhancement of 102 % was obtained at the channel flow rate of 15 LPM. The fan was …
Comparative Study On Performance Accuracy Of Three Probe And Five Probe Flow Analysers For Wind Tunnel Testing, Akhila Rupesh Ms, J V Muruga Lal Jeyan Dr
Comparative Study On Performance Accuracy Of Three Probe And Five Probe Flow Analysers For Wind Tunnel Testing, Akhila Rupesh Ms, J V Muruga Lal Jeyan Dr
International Journal of Aviation, Aeronautics, and Aerospace
In the field of inviscid fluid flow studies, the theoretical concept has to be developed even more. In order to make it possible, it is very important to supplement the concepts with strong experimental results. While performing experimentation, various accepts of design can be determined with factors influencing the and also required modification can be recommended in a more systematic and economic manner. Also, the aim objective of the experiment is to extend the underlying theory and to produce new designs with improvements that can be great support to the advancement in technology. In experimental analysis, wind tunnels are used …