Aerospace Engineering Commons^™

Mitigation Of Aeroacoustic Noise Of A Fixed Wing Using Passive Flow Control, Cameron L. Perry

College of Graduate Studies: Theses & Dissertations

As the world becomes more environmentally conscious, noise pollution is of increasing concern. In this study, shallow dimples are applied to a NACA 0012 airfoil at multiple angles of attack (AoA) with the intent of reducing aeroacoustic noise emissions. Both Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) models are used for aerodynamic and aeroacoustic investigations, respectively, at a fixed Reynolds number of 4.8 x 10⁵. Altering the dimple depth to diameter ratio (d/D) from 2.5% to 15% is first investigated, with a d/D of 5% or lower resulting in the least aerodynamic impact. The transition from …

Jet Noise Reduction: A Fresh Start, Christopher K. Tam, Fang Q. Hu

Mathematics & Statistics Faculty Publications

Attempts to reduce jet noise began some 70 years ago. In the literature, there have been many publications written on this topic. By now, it is common knowledge that jet noise consists of a number of components. They possess different spectral and radiation characteristics and are generated by different mechanisms. It appears then that one may aim at the suppression of the noise of a single component instead of trying to reduce jet noise overall. The objective of the present project is to reduce large turbulence structures noise. It is the most dominant noise component radiating in the downstream direction. …

Optimization Of Ported Cfd Kernels On Intel Data Center Gpu Max 1550 Using Oneapi Esimd, Mohammad Zubair, Aaron Walden, Gabriel Nastac, Eric Nielsen, Christoph Bauinger, Xiao Zhu

Computer Science Faculty Publications

We describe our experience porting FUN3D’s CUDA-optimized kernels to Intel oneAPI SYCL.We faced several challenges, including foremost the suboptimal performance of the oneAPI code on Intel’s new data center GPU. Suboptimal performance of the oneAPI code was due primarily to high register spills, memory latency, and poor vectorization. We addressed these issues by implementing the kernels using Intel oneAPI’s Explicit SIMD SYCL extension (ESIMD) API. The ESIMD API enables the writing of explicitly vectorized kernel code, gives more precise control over register usage and prefetching, and better handles thread divergence compared to SYCL. The ESIMD code outperforms the optimized SYCL …

Design And Validation Of An Aerodynamic System For A Formula Sae® Vehicle Using Vehicle Dynamic Simulation And Experimentation, Evan S. Cole

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis presents the design, simulation, and experimental validation for the aerodynamic system for a Formula SAE® vehicle. The Society of Automotive Engineers ® (SAE) hosts a collegiate competition annually called Formula SAE® where students design, fabricate, and test a small “formula style” vehicle. The vehicle performs in relatively slow maneuvers, around different courses and tests to evaluate the vehicle’s overall performance. Over the years, collegiate teams have put significant research into the design and manufacturing of the aerodynamics of these vehicles. In order to justify this undertaking for future teams at West Virginia University’s Formula SAE® program, a comprehensive …

Induced Drag Laboratory Curriculum With Variable Aspect Ratio Wing, Alexander Milligan, Elizabeth Plyler

Williams Honors College, Honors Research Projects

A laboratory curriculum for undergraduate students at The University of Akron enrolled in 4600:413 Introduction to Aerodynamics was created to allow students a hands-on opportunity to study the basic fundamentals of aerodynamically induced drag. To accomplish this, a 3D printed wing was created with variable aspect ratio. This wing is to be utilized in the laboratory experiment in The University of Akron subsonic wind tunnel to generate data on lift on drag at different airspeeds, angles of attack, and aspect ratios. The laboratory curriculum provides basic theory applicable to the wind tunnel experiments as well as question prompts and data …

Initial Procedure For Small-Scale Extraction Of Subsurface Martian Ice, Evan Steers

Electronic Theses and Dissertations

For decades, NASA has been surveying the surface of Mars with plans for human exploration. Due to recent advancements, there is strong evidence to believe that frozen aquifers beneath the Martian surface hold great amounts of usable H2O. Since the discovery of water on Mars, NASA has expressed key interest in harvesting this valuable resource. The presence of usable H2O on Mars could reduce the launching mass of future missions by giving astronauts the capability to harvest water once they have landed on Mars. This research focuses on the optimization of a current design to extract Martian water and the …

Design Of An Internal Osculating Waverider Intake, Mark E. Noftz, Andrew J. Shuck, Joseph S. Jewell, Jonathan Poggie, Andrew N. Bustard, Thomas J. Juliano, Nicholas J. Bisek

Publications

The design of an inward-turning, high-speed, three-dimensional streamline traced intake is presented from osculating axisymmetric theory. To satisfy the osculating intake design criteria, a stitched Busemann diffuser and Internal Conical Flow-A solution is used as the basic isentropic compressive streamline. This new contour provides efficient compression, high flow uniformity, and straight leading edge shocks of equal strength. Additionally, a novel method for constructing the inlet cowl is presented. The combined process leads to a new method of high-speed intake design. A generic shape-transitioned intake is constructed and named the Indiana Inlet for the Indiana universities that contributed to the project. …

Probabilistic Short Term Solar Driver Forecasting With Neural Network Ensembles, Joshua Daniell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Commonly utilized space weather indices and proxies drive predictive models for thermosphere density, directly impacting objects in low-Earth orbit (LEO) by influencing atmospheric drag forces. A set of solar proxies and indices (drivers), F_10.7, S_10.7, M_10.7, and Y_10.7, are created from a mixture of ground based radio observations and satellite instrument data. These solar drivers represent heating in various levels of the thermosphere and are used as inputs by the JB2008 empirical thermosphere density model. The United States Air Force (USAF) operational High Accuracy Satellite Drag Model (HASDM) relies on JB2008, and …

Design And Manufacture Of An Aerodynamic Body That Meets Scaling Law Requirements And Survives Severe G-Load Environment For Free-Flight Testing, Anthony R. Gonzalez

Graduate Theses, Dissertations, and Problem Reports (ETD)

Design and Manufacture of an Aerodynamic Body that Meets Scaling Law Requirements and Survives Severe G-load Environment for Free-Flight Testing

Anthony Gonzalez

Developing scale models to test functionality and ascertain aerodynamic properties is critical before manufacturing full-size products. Through dimensional analysis and similitude, engineers create scale models to test any parameter of interest. This research aims to design a scale model of an aerodynamic body for repeated free-flight testing. The Froude number is the dominant scale model law used to determine the geometric, mass, and inertia scaling laws. A critical requirement for this research is that the model should be …

Effects Of Pressure Side Film Cooling Hole Placement And Condition On Surface Heat Transfer Characteristics Of A Transonic Turbine Blade Tip, Hallie Collopy, Phillip M. Ligrani, Hongzhou Xu, Michael Fox

PRC-Affiliated Research

The effects of film cooling hole placement location along the upper pressure side of a transonic squealer are considered. The thermal performance of four different film cooling configurations; B1, B2, B3 and B4, are considered using the University of Alabama in Huntsville's SS/TS/WT (supersonic/transonic/wind tunnel) experimental facility and a simulated turbine blade row using a linear cascade. Surface-varying results are provided for both the squealer blade tip surface, and for the upper pressure side of the squealer blade. These results are given for blowing ratios ranging from 0.42 to 3.20 in the form of spatially-resolved and spatially-averaged adiabatic film cooling …

Noise And Propulsive Efficiency Interactions For Rotors And Propellers At Constant Thrust, Riccardo Roiati

Doctoral Dissertations and Master's Theses

In the emerging market of Advanced Air Mobility (AAM), aerospace companies have been designing and prototyping electric and hybrid vehicles to revolutionize travel. These vehicles must have low noise and particulate emissions while also having enough propulsive efficiency to complete the mission. This thesis aims to study the relationship between noise and propulsive efficiency as related to any aircraft equipped with an electric motor and a variable pitch rotor/propeller. The combination of the electric motor with the variable pitch propeller/rotor allows for a decoupled rotational speed and torque generation, meaning that the electric motor can generate the same amount of …

Quasi 1d Modelling Of A Scramjet Engine Cycle Using Heiser-Pratt Approach, Asmaa Chakir

Theses and Dissertations

Scramjet engines are key for sustained hypersonic flights. Analytic models play a critical role in the preliminary design of a scramjet engine configuration. The objective of this research is to develop and validate a quasi-1D model for the scramjet engine encompassing inlet, isolator and combustor, to evaluate the impact of flight conditions and design parameters on the engine functionality. The model is developed assuming isentropic flow in the inlet with a single turn; modified Fanno-flow equations in the isolator that account for the area change of the core flow; and the combustor is modeled using Heiser-Pratt equations accounting for the …

Development And Deployment Of A Dynamic Soaring Capable Uav Using Reinforcement Learning, Jacob Adamski

Doctoral Dissertations and Master's Theses

Dynamic soaring (DS) is a bio-inspired flight maneuver in which energy can be gained by flying through regions of vertical wind gradient such as the wind shear layer. With reinforcement learning (RL), a fixed wing unmanned aerial vehicle (UAV) can be trained to perform DS maneuvers optimally for a variety of wind shear conditions. To accomplish this task, a 6-degreesof- freedom (6DoF) flight simulation environment in MATLAB and Simulink has been developed which is based upon an off-the-shelf unmanned aerobatic glider. A combination of high-fidelity Reynolds-Averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) in ANSYS Fluent and low-fidelity vortex lattice (VLM) …

Commercial Airliner Winglet Design Optimization – A Case Study, Anthony Gutierrez

Symposium of Student Scholars

The objective of this research is to determine the effect on aerodynamic performance due to changes of winglets design variables found of the Boeing 737-700 aircraft. The various winglet types studied in this research include the blended, canted, wingtip fence and split scimitar. The variables include height, sweep angle, taper ratio, and the inclination angle. These variables are altered in 5% increments from -15% to +15% of their original baseline values. Each altered winglet design only changes one variable at a time while keeping all other variables constant. The altered models are compared to the original by finding the aerodynamic …

Artificial Neural Network For Predicting Heat Transfer Rates In Supercritical Carbon Dioxide, Vinusha Dasarla Giri Babu

Doctoral Dissertations and Master's Theses

Supercritical carbon dioxide as a working fluid in a closed Brayton cycle is proving to be more efficient than a conventional steam-based Rankine engine. Understanding the heat transfer properties of supercritical fluids is important for the design of a working engine cycle. The thermophysical properties of supercritical fluids tend to vary non-linearly near the pseudo-critical region. Traditionally, empirical correlations are used to calculate the heat transfer coefficient. It has been shown in the literature and within our own studies that these correlations provide inaccurate predictions near the pseudo-critical line, where heat transfer may be deteriorated or enhanced, resulting from strong …

Computational Fluid Dynamics Modeling Of Hemodialysis In Patients With An Arteriovenous Fistula, Maximilian Roth

McKelvey School of Engineering Graduate Student Theses & Dissertations

With the advent of arteriovenous fistula (AVF) for use in hemodialysis, the anastomosis built for such use has become a central point of the study to understand the flow and wall shear stresses in such a system since very large wall shear stresses can lead to arterial/vein rupture. Considering the commonly used creation site of an anastomosis as connecting the radial artery to the cephalic vein, a model is created to calculate the wall shear stresses across various components of the system. The model depicts a connection of the specified vein and artery bridged together allowing the increase in blood …

A Study Of Ship Airwakes Using Dual Plane Stereoscopic Piv, Guillermo Mazzilli

Doctoral Dissertations and Master's Theses

The airwake of a model Simple Frigate Shape 2 (SFS2) was studied in a low-speed wind tunnel. This airwake was measured using a novel time-dependent, dual plane, stereoscopic particle image velocimetry approach. Two flow planes over the flight deck, one parallel and one perpendicular to the free-stream were simultaneously measured. Measurements were carried out over four such pairs of streamwise-spanwise plane combinations. Additionally, the airwake with and without a simulated atmospheric boundary layer (sABL) was studied. The synchronicity of the measurements were taken advantage of to carry out conditional averages of the flow field to isolate and study certain flow …

Validation And Verification Of The Wray-Agarwal Turbulence And Algebraic Transition Models For 2d External Airfoil Flows, Dean Ryan-Simmons

McKelvey School of Engineering Graduate Student Theses & Dissertations

Validation and verification benchmark test cases are employed in computational fluid dynamics (CFD) to determine the best practices in application of various CFD tools. These cases focus on the geometry modeling, mesh generation, numerical algorithms, and turbulence models to ensure consistent and accurate numerical simulation of physical phenomena. Assessing model accuracy is essential to identify areas of improvement in various turbulence models. Flow past several symmetric NACA airfoils, namely NACA 0012, NACA 0015 and NACA 0018 are standard test cases for validating and evaluating turbulence models’ accuracy since the experimental data is available for these airfoils. Available wind tunnel data …

A Data Driven Modeling Approach For Store Distributed Load And Trajectory Prediction, Nicholas Peters

Doctoral Dissertations and Master's Theses

The task of achieving successful store separation from aircraft and spacecraft has historically been and continues to be, a critical issue for the aerospace industry. Whether it be from store-on-store wake interactions, store-parent body interactions or free stream turbulence, a failed case of store separation poses a serious risk to aircraft operators. Cases of failed store separation do not simply imply missing an intended target, but also bring the risk of collision with, and destruction of, the parent body vehicle. Given this risk, numerous well-tested procedures have been developed to help analyze store separation within the safe confines of wind …

Understanding Unsteady Corner Separation Within Wing-Body Junction Flows, Paul G. Winner

Doctoral Dissertations and Master's Theses

Wing-body junction flows, formed at the interface between a wing and fuselage surface, are a complex, coupled, three-dimensional, turbulent flow field. This thesis focused on the unsteady corner separation that develops at the trailing edge of this wing-body junction under certain conditions. A NACA 0015 wing mounted on a flat plate at an angle of attack of 13°was used as the model junction flow field. The wing had an aspect ratio of 8 with a linear washout twist of 15°. The Reynolds number based on the wing chord was Re_c = 4.5 × 10⁵. Time-dependent stereoscopic particle …

Machine Learning In Aerodynamic Shape Optimization, Jichao Li, Xiaosong Du, Joaquim R.R.A. Martins

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Machine learning (ML) has been increasingly used to aid aerodynamic shape optimization (ASO), thanks to the availability of aerodynamic data and continued developments in deep learning. We review the applications of ML in ASO to date and provide a perspective on the state-of-the-art and future directions. We first introduce conventional ASO and current challenges. Next, we introduce ML fundamentals and detail ML algorithms that have been successful in ASO. Then, we review ML applications to ASO addressing three aspects: compact geometric design space, fast aerodynamic analysis, and efficient optimization architecture. In addition to providing a comprehensive summary of the research, …

Development Of A Trailing Edge Flap Using A Compliant Mechanism, Matthew Maybee

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

A Study Of Pressure Probe Response In Steady And Unsteady Flows, Michael T. Charonnat

Master's Theses

The objective of this thesis is two-fold: to analyze the directional calibration of a 3-hole probe in steady flow and to develop a method for the interpretation of measurements recorded with a novel, fast-response Pitot-type probe in unsteady, turbulent flow. Calibration data for the 3-hole probe’s two side ports was taken in the steady, non-turbulent region of a free jet and was evaluated for symmetry. In addition, data that was recorded using one side port in two independent calibration runs was compared to study repeatability. Misalignment was found between the nominally symmetric data sets, which may be the result of …

Low-Reynolds-Number Locomotion Via Reinforcement Learning, Yuexin Liu

Dissertations

This dissertation summarizes computational results from applying reinforcement learning and deep neural network to the designs of artificial microswimmers in the inertialess regime, where the viscous dissipation in the surrounding fluid environment dominates and the swimmer’s inertia is completely negligible. In particular, works in this dissertation consist of four interrelated studies of the design of microswimmers for different tasks: (1) a one-dimensional microswimmer in free-space that moves towards the target via translation, (2) a one-dimensional microswimmer in a periodic domain that rotates to reach the target, (3) a two-dimensional microswimmer that switches gaits to navigate to the designated targets in …

Comprehensive Review Of Heat Transfer Correlations Of Supercritical Co2 In Straight Tubes Near The Critical Point: A Historical Perspective, Nicholas C. Lopes, Yang Chao, Vinusha Dasarla, Neil P. Sullivan, Mark Ricklick, Sandra Boetcher

Publications

An exhaustive review was undertaken to assemble all available correlations for supercritical CO2 in straight, round tubes of any orientation with special attention paid to how the wildly varying fluid properties near the critical point are handled. The assemblage of correlations, and subsequent discussion, is presented from a historical perspective, starting from pioneering work on the topic in the 1950s to the modern day. Despite the growing sophistication of sCO2 heat transfer correlations, modern correlations are still only generally applicable over a relatively small range of operating conditions, and there has not been a substantial increase in predictive capabilities. Recently, …

Experiments To Mitigate Flow Recirculation In A Closed Anechoic Chamber Using Mesh Screens As Turbulence Suppressors, Tori Kay Wolverton

Theses and Dissertations

The desire to gather acoustic data of a propeller in simulated hover without environmental effects is met with the challenge of recirculating flow in a closed anechoic chamber. Flow recirculation in an anechoic chamber is not ideal because the effects of it being ingested by the rotor cause unsteady loadings on the propeller. This unsteady loading causes vortex noise from the turbulence introduced by the recirculation of the flow. The aim is to study the acoustic signature of a propeller separate from external factors and engine noise. Two different propellers with three different screen combinations were tested in a closed …

Aerodynamics And Vibrations Of A Helicopter Rotor Blade, Mohammad Khairul Habib Pulok

LSU New Orleans Theses and Dissertations

The nature of the aerodynamic environment surrounding a helicopter causes a significant amount of vibration to its whole body. Among different sources of vibrations, the aerodynamic loading on the main rotor blade is the major contributor. Therefore, analyzing a rotor blade's vibration characteristics and aerodynamic behavior becomes essential. The vortex characteristics and the wake surrounding a helicopter rotor blade play an important role because they affect the aerodynamic behavior of the rotor blade. An advanced mathematical and computational model of rotor wake and blade vortex gives a better understanding of the helicopter rotor dynamics. This study develops computational models of …

Foundations For Finite-State Modelling Of A Two-Dimensional Airfoil That Reverses Direction, Jake Michael Oscar Welsh

McKelvey School of Engineering Graduate Student Theses & Dissertations

Current 3-D finite-state wake models are incapable of simulating a maneuver in which the sign of the free-stream velocity changes direction and the rotor enters its own wake -- as might occur in the case of a helicopter which ascends and then descends. It is the purpose of this work to create a 2-D finite-state wake model which is capable of handling changes in free-stream direction as a precursor to development of a 3-D model that can do the same.

The 2-D finite-state model used for reentry modifications is an existing model created by Peters, Johnson, and Karunamoorthy. By the …

Controller Platform Design And Demonstration For An Electric Aircraft Propulsion Driv, Rosten Sweeting

Graduate Theses and Dissertations

With the growth in the aerospace industry there has been a trend to optimize the performance of an aircraft by reducing fuel consumption and operational cost. Recent advancements in the field of power electronics have pushed towards the concepts of hybrid electric aircraft also known as more electrical aircrafts. In this work, a custom controller board for an electric aircraft propulsion drive was designed to drive a permanent magnet synchronous motor. Design of the controller board required knowledge of the topology selection and power module selections. Simulations of the system were performed using MATLAB/Simulink to analyze the overall performance of …

Studies Of Multiphase Distribution And Flow In Bubble/ Slurry Bubble Columns With /Without Internals And Advanced Sustainable Construction Materials Using Sophisticated Measurement Techniques, Omar Farid

Doctoral Dissertations

"Bubble/slurry bubble columns have been widely studied and employed as multiphase flow reactors with and without vertical heat-exchanging tubes. In order to understand more deeply the effect of the dense internals on the hydrodynamics of bubble/slurry bubble column, systematic experiments were performed to visualize and quantify using the radioactive particle tracking (RPT) technique. A new methodology for implementing the radioactive particle tracking (RPT) technique has been developed to investigate the effect of the dense internals on the hydrodynamics of the bubble/slurry column reactor. Monte Carlo N-Particle (MCNP) simulation has been implemented to simulate the system to generate a large number …