Analysis Of Wingtip Vortex Structure Generated By Bio-Inspired Winglets, 2024 Embry-Riddle Aeronautical University
Analysis Of Wingtip Vortex Structure Generated By Bio-Inspired Winglets, D'Zahn A. Smith
Doctoral Dissertations and Master's Theses
Bio-inspired winglets were studied with the goal of better understanding the structure of the wingtip vortices they generate. Measurements of the tip vortex were previously carried out using stereoscopic particle image velocimetry (sPIV). The bio-inspired winglet was tested on a rectangular NACA 0012 wing section at a 5-degree angle of attack and at a chord Reynolds number of 900,000. Velocity field measurements were recorded at 0.7 and 2 chord lengths aft of the wing’s trailing edge. Compared to the wing with no attachment and a traditional blended winglet, the bio-inspired winglet’s vortex exhibited significantly less intense flow field properties. These …
Modeling Of Rotor Wake Vortex Dynamics And Interactions In Non-Homogenous Vertiport Environments, 2024 Embry-Riddle Aeronautical University
Modeling Of Rotor Wake Vortex Dynamics And Interactions In Non-Homogenous Vertiport Environments, Garrison P. Shaw
Doctoral Dissertations and Master's Theses
The current research serves to analyze and study the effects ground forces can have on the thrust performance of a propeller in multiple different configurations. The current research utilizes an open source Computational Fluid Dynamics (CFD) software known as OpenFOAM to generate calculate and visualize these runs. The model used for this experiment is a hybrid model that employs both a Unsteady Reynolds-Averaged Navier-Stokes (URANS) and a detached eddy simulation using a hybrid Large Eddy Simulation (LES) via a KomegaSSTDDES model. This model serves to save computational time as well as allow for accurate results. The three cases run are …
Characterization And Analysis Of Supersonic Flow Through De Laval Nozzles At Varied Design Conditions, 2024 Embry-Riddle Aeronautical University
Characterization And Analysis Of Supersonic Flow Through De Laval Nozzles At Varied Design Conditions, Sarah Baird
Doctoral Dissertations and Master's Theses
A combined numerical and experimental investigation of supersonic planar nozzles under different design conditions has been conducted. Supersonic planar nozzles are common geometries observed in supersonic wind tunnels and aircraft or rocket engines. For the important role they play in wind tunnel testing and aircraft propulsion, it is important to conduct a thorough numerical and experimental study to characterize their performance at different operating conditions. In this study, a de Laval nozzle was scanned to extract its contours and subsequently modeled to compare analytical and numerical performance expectations under design and off-design conditions. The nozzle was then installed in a …
An Investigation Into In-Flight Loss Of Control Accidents Due To Horizontal Stabilizer Changes On The Piper Cherokee, 2024 Florida Institute of Technology
An Investigation Into In-Flight Loss Of Control Accidents Due To Horizontal Stabilizer Changes On The Piper Cherokee, Connor John Geran
Theses and Dissertations
Loss of Control (LOC) while in-flight in General Aviation (GA) has been the subject of intense research by academic institutions and regulatory agencies in recent years [4] [9] [11] [19] [20] [21]. This interest is primarily due to a disproportionate number of all aircraft accidents occurring within the GA category of flight, with 94% of accidents in 2022 occurring within GA, caused primarily by pilot LOC, with 42% of accidents having LOC as the listed cause. Research into this subject at FIT yielded the results that many common GA aircraft tend to experience a strong pitch up response after undergoing …
Aerodynamic Design And Analysis Of A Modified 2006 Mazda Miata, 2024 Georgia Southern University
Aerodynamic Design And Analysis Of A Modified 2006 Mazda Miata, William N. Recher
Honors College Theses
Aerodynamic forces developed by automobiles have destabilizing effects at high speed. These forces tend to skew toward a vehicle’s rear which can present safety concerns, especially for rear-wheel-drive automobiles like the Mazda Miata. To address oversteer and high-speed instability, a vehicle’s design can be tailored to bring about aerodynamic balance and improve traction. LiDAR was used to bring the physical automobile into the digital space. Then, a splitter and diffuser were added to reduce the magnitude of the destabilizing forces. Next, the size and shape of the rear-wing required to balance the vehicle was calculated using a combination of parameters …
Martian Atmospheric Rover Simulation (M.A.R.S.), 2024 Florida Institute of Technology
Martian Atmospheric Rover Simulation (M.A.R.S.), Matt Berard, Shelby Beddard, Alexander Brunette, Emma Conti, Collin Duke, Delaney Novak, Keelin Weaver
Aerospace, Physics, and Space Science Student Publications
While rovers have been used by various agencies to explore Mars, their travel is limited by terrain obstacles, which may prevent mission completion. Creating a vehicle equipped with both driving and flight capabilities would allow greater range of motion on extraterrestrial planets. Integrating the technology for both transportation modes into one rover allows for efficiency and advancements in technological and planetary research.
Development Of Eagle3d Solver For Wall Modeled Les Of Transonic Flows, 2024 Embry-Riddle Aeronautical University
Development Of Eagle3d Solver For Wall Modeled Les Of Transonic Flows, Spencer Moore
Doctoral Dissertations and Master's Theses
Wall modeled Large Eddy Simulation (LES) is an area of interest due to its ability to lower computational costs of LES simulation. Even with the application of wall models, LES still proves to have practicality issues when it comes to use in industry, due to the expertise, time, and computational resources required to get results. A case described by an axisymmetric transonic bump is explored utilizing the Embry-Riddle Aeronautical Universities in house unstructured finite volume multi-element CFD code, Eagle3D. Eagle3D, has been brought to the state of the art and validated against current research using this transonic bump case as …
Adaptive Control Of An Aeroelastic System For Active Flutter Suppression And Disturbance Rejection, 2024 Embry-Riddle Aeronautical University
Adaptive Control Of An Aeroelastic System For Active Flutter Suppression And Disturbance Rejection, Patrick Sterling Downs
Doctoral Dissertations and Master's Theses
The future of aircraft design strives for lighter weight, more aerodynamically efficient structures. These improvements may come with the drawback of increased structural flexibility and elevated aeroelastic effects, often resulting in a lower flutter speed. This motivates the implementation of advanced control methods to control aeroelastic systems over a range of flight conditions, suppress and delay the onset of flutter, and compensate for disturbances, actuator dynamics, and unmodeled nonlinear dynamics.
This dissertation first develops a novel method for constructing time-domain simulation models of two and three-dimensional aeroelastic systems, resulting in models that are suitable for the implementation of state-space control …
Development Of Eagle3d Solver For Wall Modeled Les Of Transonic Flows, 2024 Embry-Riddle Aeronautical University
Development Of Eagle3d Solver For Wall Modeled Les Of Transonic Flows, Spencer Moore
Doctoral Dissertations and Master's Theses
Wall modeled Large Eddy Simulation (LES) is an area of interest due to its ability to lower computational costs of LES simulation. Even with the application of wall models, LES still proves to have practicality issues when it comes to use in industry, due to the expertise, time, and computational resources required to get results. A case described by an axisymmetric transonic bump is explored utilizing the Embry-Riddle Aeronautical Universities in house unstructured finite volume multi-element CFD code, Eagle3D. Eagle3D, has been brought to the state of the art and validated against current research using this transonic bump case as …
Mitigating Engine Unstart In Scramjets With Porous Bleeders, 2024 Embry-Riddle Aeronautical University
Mitigating Engine Unstart In Scramjets With Porous Bleeders, Ryan Lindley
Doctoral Dissertations and Master's Theses
The effectiveness of porous bleeders in mitigating unstart phenomena and enhancing isolator effectiveness in a hypersonic scramjet was investigated. Through computational fluid dynamics simulations, the impact of porous bleeder design parameters such as pressure jump coefficient and bleeder size on isolator effectiveness and unstart prevention was evaluated. Results indicated that porous bleeders delayed flow separation and reduced adverse pressure gradients, thereby enhancing isolator performance. Additionally, porous bleeders demonstrated promising capabilities in preventing full unstart events and mitigating oscillatory unstart phenomena.
Numerical Study In Wind Energy Extraction From Controlled Limit-Cycle Oscillations In Modified Glauert Airfoil, 2024 Embry-Riddle Aeronautical University
Numerical Study In Wind Energy Extraction From Controlled Limit-Cycle Oscillations In Modified Glauert Airfoil, Ethan L. Deweese
Doctoral Dissertations and Master's Theses
Typically, wind energy harvesting technology employs wind turbines. Towards the goal of meeting increasing energy needs with renewable energy sources a novel wind energy harvesting scheme is considered, utilizing a modified Glauert (MG) airfoil experiencing aeroelastic limit cycle oscillation (LCO) from which energy may be extracted. Synthetic jet actuators (SJA)s are used along with the unique geometry of the MG airfoil to control flow separation and amplify the LCO and energy generation potential of the system. The discussed wind energy harvesting scheme could provide flexibility in allowing installations previously unsuitable to wind turbines due to geometric or low wind velocity …
On Progress In Exploring Controlled Viscous Limit-Cycle Oscillations In Modified Glauert Airfoil, 2024 Embry-Riddle
On Progress In Exploring Controlled Viscous Limit-Cycle Oscillations In Modified Glauert Airfoil, Ethan Deweese, Lap Nguyen, Erik Vataker, William Mackunis, Vladimir Golubev, Ron Efrati, Oksana Stalnov
Publications
The paper reports on the progress in the development of a novel robust, nonlinear flow control technology that employs an array of synthetic-jet actuators (SJAs) embedded in 2-DOF, elastically mounted, optimized Modified Glauert (MG) airfoil design in order to control limit cycle oscillations (LCO) at low subsonic flow regimes. The focus here is on the conceptual design of the wind energy harvesting system that employs, e.g., a piezoelectric device to extract energy from plunging LCO, with the closed-loop controller being capable to sustain the required LCO amplitudes over a wide range of wind speeds. The current high-fidelity studies first include …
Experimental Environmental Profiles And Sloshing Dynamics Aboard Zero-G Aircraft, 2024 Embry-Riddle Aeronautical University
Experimental Environmental Profiles And Sloshing Dynamics Aboard Zero-G Aircraft, Pedro J. Llanos, Sathya Gangadharan, Kevin Crosby
Publications
This study presents the results of a parabolic flight experiment to study the sloshing dynamics of the magneto-active propellant management device experiment. This device utilizes a magnetoactive membrane and magnets located external to the tank to effectively damp the liquid free surface motion. This research work establishes a benchmark with sloshing analytical formulation and sensor calibration methods that can be used to characterize future research parabolic flights while providing important environmental profiles measured during flight, such as accelerations, pitch angle, velocity, temperature, total volatile content, carbon dioxide, relative humidity, magnetic field, and radiation. Correlation between these flight variables and the …
Aerothermodynamic Analysis Of A Linear Aerospike Fueled With Liquid Methane Using Cfd, 2024 Georgia Southern University
Aerothermodynamic Analysis Of A Linear Aerospike Fueled With Liquid Methane Using Cfd, Aidan Rowell
Honors College Theses
Renewed interest in manned spaceflight, mostly spurred by the advancement of commercial spacecraft, has led to growing interest in improving the efficiency of rocket engines. Aerospike nozzles have the potential to provide this boost in efficiency to spacecraft and thus lower costs and increase payload capacity. This type of nozzle is what is known as altitude adjusting and can significantly increase efficiency. When paired with propellants such as methane/oxygen, which can be manufactured in-situ on some planetary bodies and has a higher density than traditional propellants like liquid hydrogen/liquid oxygen, even more efficiency gain can be achieved. To understand the …
On The History And Semantics Of Burble In Aerodynamic Theory, 2024 Utah State University
On The History And Semantics Of Burble In Aerodynamic Theory, Benjamin C. Moulton, Cory D. Goates, Troy A. Abraham
Mechanical and Aerospace Engineering Student Publications and Presentations
The term burble has been in use in aerodynamic theory for over a century. While burble may be unfamiliar to most contemporary aerodynamicists, the word has a rich history based in aerodynamic theory and experimentation. The present paper outlines the fluidity of burble's meaning over time. From analyzing subsonic flow over an airfoil, to the implementation of stochastic turbulence in aircraft carrier landing simulations, the term burble has had a significant impact on the study of aerodynamics. The term burble has fallen out of use in aerodynamic engineering circles. Why did this happen? And what can be learned from the …
Dynamical Modeling Of Resistojet Style Thrusters For Fault Detection, And Fault Identification, 2024 University of Vermont
Dynamical Modeling Of Resistojet Style Thrusters For Fault Detection, And Fault Identification, Jonathan Leo Kerivan
Graduate College Dissertations and Theses
The work presented in this thesis investigates and validates the dynamic modeling, fault detection, and fault identification (FDI) for the resistojet thruster system, typically used in low magnitude thrust applications for smaller spacecraft. The resistojet thruster is an improvement upon the widely utilized cold gas thruster, featuring an incorporated heating section aimed at improving propellant efficiency. This additional heating section enhances the performance of the system by increasing the propellant’s thermal energy before its discharge through the nozzle, subsequently leading to a reduction in overall fuel consumption. To implement a model-based FDI technique tailored to the typical resistojet thruster system, …
Depressurization Characteristics Of Steam-Based Reciprocating Vacuum Pump, 2023 New Jersey Institute of Technology
Depressurization Characteristics Of Steam-Based Reciprocating Vacuum Pump, Hongling Deng
Dissertations
This dissertation introduces a novel vacuum technology that leverages low-pressure saturated steam and cooling-controlled condensation, offering an efficient way to utilize low-grade thermal energy sources like waste heat, steam, or solar energy. At the heart of this technology is a unique duo-chamber vacuum pump system, featuring a reciprocating piston and a heat-conductive wall, designed to generate a vacuum through steam-condensation and cooling processes.
The core of this research lies in developing and validating mechanistic models for the steam-condensation depressurization process, a complex phenomenon involving phase change and transport mechanisms. Prior to this work, these mechanisms were not sufficiently modeled or …
Numerical Study Of Owls' Leading-Edge Serrations, 2023 Coastal Carolina University
Numerical Study Of Owls' Leading-Edge Serrations, Asif Shahriar Nafi, Nikolaos Beratlis, Elias Balaras, Roi Gurka
Physics and Engineering Science
Owls' silent flight is commonly attributed to their special wing morphology combined with wingbeat kinematics. One of these special morphological features is known as the leading-edge serrations: rigid miniature hook-like patterns found at the primaries of the wings' leading-edge. It has been hypothesized that leading-edge serrations function as a passive flow control mechanism, impacting the aerodynamic performance. To elucidate the flow physics associated with owls' leading-edge serrations, we investigate the flow-field characteristic around a barn owl wing with serrated leading-edge geometry positioned at 20° angle of attack for a Reynolds number of 40 000. We use direct numerical simulations, where …
Aerodynamic Dimpling For The Nose Cone Of A High-Power Competition Rocket, 2023 University of New Mexico
Aerodynamic Dimpling For The Nose Cone Of A High-Power Competition Rocket, Graham Geoffrey Monroe
Mechanical Engineering ETDs
This thesis investigates nose cone dimpling for the reduction of the aerodynamic drag of a Level 3 High-Power amateur rocket. Two rocket launches were conducted. The first used a COTS nose cone with a smooth surface. A dimple distribution was created according to dimensions calculated by Sandia National Laboratories’ proprietary Right- Size Dimple Evaluator. A dimpled nose cone, designed with geometry matching the COTS component, was 3D printed. Axial acceleration and barometric pressure data, recorded by an onboard flight computer, were used to calculate and plot the drag coefficient as a function of the Reynolds number for the smooth and …
Investigation And Control Of Görtler Vortices In High-Speed Flows, 2023 Mississippi State University
Investigation And Control Of Görtler Vortices In High-Speed Flows, Omar Es-Sahli
Theses and Dissertations
High-amplitude freestream turbulence and surface roughness elements can excite a laminar boundary-layer flow sufficiently enough to cause streamwise-oriented vortices to develop. These vortices resemble elongated streaks having alternate spanwise variations of the streamwise velocity. Following the transient growth phase, the fully developed vortex structures downstream undergo an inviscid secondary instability mechanism and, ultimately, transition to turbulence. This mechanism becomes much more complicated in high-speed boundary layer flows due to compressibility and thermal effects, which become more significant for higher Mach numbers. In this research, we formulate and test an optimal control algorithm to suppress the growth rate of the aforementioned …