Santa Clara University
University of Tennessee, Knoxville
Embry-Riddle Aeronautical University
Linfield College
California Polytechnic State University, San Luis Obispo
Union College - Schenectady, NY
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 …
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, …
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 …
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 …
Husker Motorsports Active Drag Reduction System,
2023
University of Nebraska - Lincoln
Husker Motorsports Active Drag Reduction System, Creighton Hughes, Evan Killian, Micah Busboom, Aj Johnson, Jude Steffen
Honors Theses
Formula SAE is a multifaceted competition that involves student teams designing and competing with an open-wheel style race car. There are 5 different dynamic events included in the competition. Each event requires a unique aerodynamic setup to have the best performance possible. This design project focuses on a drag reduction system (DRS) that will improve aerodynamic performance, resulting in faster lap times and increased competitiveness. Key features include a direct electronic actuation mechanism that will allow the rear wing to be adjusted during a race. The benefits of the DRS system, include increased speed, improved handling, and greater fuel efficiency …
Analysis Of An Electrospray Thruster With A Concave Propellant Meniscus,
2023
University of Tennessee, Knoxville
Analysis Of An Electrospray Thruster With A Concave Propellant Meniscus, Adam Nicholas Huller
Masters Theses
The low thrust, high specific impulse, and low mass of electrospray thrusters (ETs) make them ideal for maneuvering nanosatellites, especially with the new requirement to deorbit a satellite within five years of completing its mission. These innovative thrusters use electrohydrodynamic principles of electrospray (ES) to provide thrust. These principles have been subject to much research over the past decade, though much more research is needed to fully understand the underlying physics of these thrusters. The first part of this study establishes a procedure for analyzing the theoretical thrust performance of an ET, by using propellant properties and well-documented ES scaling …
Development Of Load Measurement Technique For Arbitrary Shapes,
2023
California Polytechnic State University, San Luis Obispo
Development Of Load Measurement Technique For Arbitrary Shapes, Quintin J. Cockrell
Master's Theses
Obtaining aerodynamic forces and moments about all three orthogonal axes for arbitrary shapes at arbitrary orientations in a fast manner via a measurement technique specific to Cal Poly’s low-speed wind tunnel to continually obtain the forces and moments under quasi-steady conditions is explored. A Continuous Rotation Technique (CR) uses a 6-DOF load cell and stepper motor to rotate an object about an axis for a complete rotation. The forces and moments acting upon the object pass through the stepper motor and interface plates and recorded by the load cell as the object is rotated continuously a finite number of rotations. …
Parametric Optimization Of A Wing-Fuselage System Using A Vorticity-Based Panel Solver,
2023
California Polytechnic State University, San Luis Obispo
Parametric Optimization Of A Wing-Fuselage System Using A Vorticity-Based Panel Solver, Chino Cruz
Master's Theses
Aerodynamic topology optimization is a useful tool in the aerodynamic design pro-
cess, especially when looking for marginal gains within a design. One example is
a turboprop racer concept aircraft that is designed with the goal of breaking world
speed records. An optimization framework was developed with the intention of later
being applied to this design. In the early design stages, the optimization framework
must focus on quicker methods of drag estimation, such as a panel codes. The large
number of design variables in topology optimization can exponentially increase func-
tion evaluations and thus computational cost. A vorticity-based panel solver …
Augmenting External Surface Pressures’ Predictions On Isolated Low-Rise Buildings Using Cfd Simulations,
2023
Louisiana State University
Augmenting External Surface Pressures’ Predictions On Isolated Low-Rise Buildings Using Cfd Simulations, Md Faiaz Khaled, Aly Mousaad Aly
Faculty Publications
The aim of this paper is to enhance the accuracy of predicting time-averaged external surface pressures on low-rise buildings by utilizing Computational Fluid Dynamics (CFD) simulations. To achieve this, benchmark studies of the Silsoe cube and the Texas Tech University (TTU) experimental building are employed for comparison with simulation results. The paper is structured into three main sections. In the initial part, an appropriate domain size is selected based on the precision of mean pressure coefficients on the windward face of the cube, utilizing Reynolds Averaged Navier-Stokes (RANS) turbulence models. Subsequently, recommendations regarding the optimal computational domain size for an …
State Space Modeling And Estimation Of Flexible Structure Using The Theory Of Functional Connections,
2023
Embry-Riddle Aeronautical University
State Space Modeling And Estimation Of Flexible Structure Using The Theory Of Functional Connections, Carlo Lombardi, Riccardo Bevilacqua
Student Works
In this work, we present a novel method to model the dynamics of a continuous structure based on measurements taken at discrete points. The method is conceived to provide new instruments to address the problem of flexible dynamics modeling in a spacecraft, where an effective mathematical representation of the non-rigid behavior of the is of critical importance in the design of an effective and reliable attitude estimation and control system. Both the measurements and the model that describes the structure can be affected by uncertainty. The purpose of the developed method is to estimate the position and the velocity of …
Mechanical Design And Fabrication Of Rotating Test Stand For Supersonic Wind Tunnel,
2023
California Polytechnic State University, San Luis Obispo
Mechanical Design And Fabrication Of Rotating Test Stand For Supersonic Wind Tunnel, Suren I. Sanai, Sam Groom, Peter Kim, Nandeesh Hiremath
College of Engineering Summer Undergraduate Research Program
This research project focuses on the design and manufacturing of a rotating test stand for the Cal Poly Supersonic Wind Tunnel (SSWT). In order to establish essential design parameters, the project employs compressible flow isentropic relationships to calculate the Mach number within the test section and determine static pressures. This comprehensive effort integrates preliminary design and manufacturing processes, utilizing CAD designs and a range of machinery for component fabrication, while also highlighting initial testing of the rotating test stand's ability to withstand predicted aerodynamic loads. As part of the research's future work, rigorous structural stability testing and the implementation of …
A New Empirical Law For The Prediction Of The Zero-Lift Pitching Moment Coefficient Of Swept And Tapered Wings,
2023
Ecole d’aviation de Borj El Amri, Tunisia
A New Empirical Law For The Prediction Of The Zero-Lift Pitching Moment Coefficient Of Swept And Tapered Wings, Mondher Yahyaoui
Journal of Aviation Technology and Engineering
A new empirical law for the prediction of the zero-lift pitching moment coefficient of trapezoidal wings with linear twist and constant taper and sweep in subsonic flow is introduced. This law is quite general in that it does not rely on the use of charts and spans the normal range of values of taper ratio, aspect ratio, and sweep for subsonic aircraft. It does not, however, accommodate different airfoils along the wingspan and only positive sweep has been considered. The empirical law was first derived for the incompressible regime and then an additional empirical law for the compressibility effect has …
An Analysis Of Aerodynamic Design Issues Of Box-Wing Aircraft,
2023
Air Force Institute of Technology, Kaduna Nigeria
An Analysis Of Aerodynamic Design Issues Of Box-Wing Aircraft, Paul Jemitola, Paul Okonkwo
Journal of Aviation Technology and Engineering
The potential of the joined/box-wing aircraft as an environmentally friendly airliner that is capable of meeting current and future emission thresholds led to the investigation of this concept. This study reviews the evolution and current trends in the aerodynamic design of the box-wing aircraft with specific emphasis on box-wing theory, airfoil characteristics, and aerodynamic issues of the box-wing aircraft. The study was undertaken to highlight the distinct features of the box-wing configuration which make it very attractive for future airliners. The study reveals that the box-wing aircraft possesses a significant aerodynamic advantage over conventional aircraft. The box-wing aircraft configuration is …
A Framework And Approach For Leveraging Unsteady Response In Turbocompressor Flowfields,
2023
Dartmouth College
A Framework And Approach For Leveraging Unsteady Response In Turbocompressor Flowfields, Eric M. Krivitzky
Dartmouth College Ph.D Dissertations
Turbomachinery is an essential technology in the transfer of mechanical work to or from a fluid stream. Forming a cornerstone component in nearly all electrical energy production and air transportation propulsion systems, turbomachinery also accounts for significant en- ergy transfer due to its omnipresence in fluid handling, including water pumping and pro- cess machinery. As system designers look towards optimized arrangements that enhance system flexibility to highly variable conditions, increase the density of energy transfer, and reduce the amount of lost work, the performance and operability demands on turbomachin- ery components continue to increase. For turbocompressors, a turbomachinery subtype that …
Flow Induced Vibration In Corrugated Metal Flexhoses,
2023
University of Central Florida
Flow Induced Vibration In Corrugated Metal Flexhoses, Patrick Tran
Electronic Theses and Dissertations, 2020-
This study on flow-induced vibration provides valuable insights into the fundamental dynamics of fluid-structure interactions. The findings contribute to the development of predictive models and design guidelines for engineering systems susceptible to flow-induced vibration. By improving our understanding of this phenomenon, engineers can enhance the safety and reliability of various structures subjected to fluid flow, such as pipelines, flexhoses, and bellows. Flowinduced vibration is a phenomenon that occurs when fluid flow interacts with a structure, leading to oscillations and potentially causing mechanical damage. Understanding the underlying mechanisms and predicting the vibration characteristics is crucial for the design and safe operation …
A Study Of The Performance Of Wind Turbines Fitted With Sprayed Liquid Flaps,
2023
University of Central Florida
A Study Of The Performance Of Wind Turbines Fitted With Sprayed Liquid Flaps, Alexander Spitzer
Electronic Theses and Dissertations, 2020-
Lift generating technologies are often considered a potential solution to increased power generation and reliability within wind turbine design. The Sprayed Liquid Flap (SLF) is a novel active control method that has shown success in providing lift generation on aircraft wings, but its application in the context of rotating flows is unexplored. This research aims to understand the effects of the SLF on a wind turbine and provide a pathway for future exploration of its aerodynamic impacts on rotating flows. Computational Fluid Dynamics with an Euler-Euler multiphase approach is employed to assess the influence of the SLF on a wind …
A Study Of The Influence Of Heat Flux On Aerodynamics In Hypersonic Flow,
2023
University of Central Florida
A Study Of The Influence Of Heat Flux On Aerodynamics In Hypersonic Flow, Kristina Pionessa
Electronic Theses and Dissertations, 2020-
This study investigates the utilization of computational fluid dynamics (CFD) to simulate aerodynamic heating effects in support of research and design endeavors. The initial investigation demonstrates the effectiveness of a computational approach in analyzing different geometries and flow conditions. Specifically, CFD is employed to analyze the aerodynamics of a blunt cone, double cone, and hypersonic leading edge experiencing a changing heat source across the flow/body boundary. At the stagnation point, maximum thermal loading occurs as previously found; therefore, boundary layer thickness and shock standoff distance is measured at that position to compare the results of each case. Characteristics such as …
A High-Pressure Shock Tube Study Of Hydrogen And Ammonia Addition To Natural Gas For Reduced Carbon Emissions In Power Generation Gas Turbines,
2023
University of Central Florida
A High-Pressure Shock Tube Study Of Hydrogen And Ammonia Addition To Natural Gas For Reduced Carbon Emissions In Power Generation Gas Turbines, Michael Pierro
Electronic Theses and Dissertations, 2020-
Ignition delay times from undiluted mixtures of natural gas (NG)/H2/Air and NG/NH3/Air were measured using a high-pressure shock tube at the University of Central Florida. The combustion temperatures were experimentally tested between 1000-1500 K near a constant pressure of 25 bar. Mixtures were kept undiluted to replicate the same chemistry pathways seen in gas turbine combustion chambers. Recorded combustion pressures exceeded 200 bar due to the large energy release, hence why these were performed at the high-pressure shock tube facility. The data is compared to the predictions of the NUIGMech 1.1 mechanism for chemical kinetic model validation and refinement. An …
The Effects Of Microgravity On The Development Of Osteoporosis,
2023
University of Central Florida
The Effects Of Microgravity On The Development Of Osteoporosis, Jackson Asiatico
Electronic Theses and Dissertations, 2020-
Previous research has identified a potential link between microgravity conditions and the onset of osteoporosis, a connection that stems from altered fluidic pathways crucial in nutrient dispersion and cell stimulation. Specifically, the absence of mechanical loading in space environments reduces fluid shear stress, thereby disrupting the normal flow of interstitial fluid in trabecular bone. This disruption greatly impacts the functionality of osteoblasts and osteoclasts, the vital cells responsible for maintaining healthy bones. The focus of this study aims to explore the impact of microgravity on bone loss in astronauts, establishing the connection between the lack of mechanical loading and the …
