Aerodynamics and Fluid Mechanics Commons^™

Wind Tunnel Instrumentation And Testing, Nicholas Marek, Abraham Mezera, Laura Jin, Hayden Smith, Curtis Cook

Student Scholar Symposium

The Raymond B. Jones College of Engineering was contacted by an automotive engineering firm seeking to use the college’s wind tunnel for gathering data on the aerodynamic performance of a proprietary prototype automotive door. Specifically, the client requested the quantification of the drag coefficient of the model at extreme wind speeds. The drag coefficient, a dimensionless number that quantifies the resistance of a specific geometric shape to airflow, will be a valuable datapoint for the client’s design iteration. Due to the sensitive nature of their work, the client has wished to remain anonymous. RBJCOE professors tasked a senior design team …

Design Of An Active-Control Pressure Regulator For A Rocket, Seth Arkwright

Williams Honors College, Honors Research Projects

An electronically actuated pressure-regulation valve and controller are necessary for maintaining pressure levels in a pressure-fed liquid-fueled rocket engine. Mechanical regulators are too heavy and have unacceptably high-pressure variation throughout the operation of a dynamic system like a rocket. Developing an electronic pressure regulator using a PID controller is a method by which a reliable, accurate, and lightweight flow regulator can be built for use on a rocket vehicle. This work will outline the development of flow simulations, PID controller, physical valve hardware, and initial testing.

Review: Dielectric Barrier Discharge Plasma Actuators For In-Flight Applications, Sabeel Saleem Mohammed

Anthós

Dielectric barrier discharge (DBD) is a phenomenon observed when high voltage is passed through a dielectric barrier at high frequencies. Current DBD plasma actuators (PAs) excel at laminar fluid boundary layer control but suffer from limited momentum flux and fluid mechanic inefficiencies. In this article, Mohammed analyzes previous discourse on DBD PAs and offers directions for future research and potential DBD PA applications. Previous work on DBD PAs documented thrust generation at high voltages and frequencies, thrust in varying fluid compositions, and vortex generation. However, certain arrangements hinder flow magnitudes, limiting the use of multiple DBD PAs in close proximity. …

Interaction Of Particles With Plasma And Shock Produced By Pulsed Spark Discharge, Shomik Mukhopadhyay

Dissertations

Interactions of powders with high-temperature plasma and shockwaves occur in diverse scenarios, such as nuclear blasts, accidental industrial dust explosions, solid propellant combustion in explosive charges and when removing contaminants from surfaces. Electrostatic Discharge (ESD), known for generating shock and plasma, is a promising lab-scale technique for simulating these interactions. Studies with ESD involved placing powders near a spark-producing gap between electrodes and observing mechanical and chemical processes like particle motion and ignition. A limited range of spark conditions and material properties have been tested, which facilitated the development and validation of preliminary computational models describing this system. Significant gaps …

Topologically Optimized Electrodes For Electroosmotic Actuation, Jianwen Sun, Jianyu Zhang, Ce Guan, Teng Zhou, Shizhi Qian, Yongbo Deng

Mechanical & Aerospace Engineering Faculty Publications

Electroosmosis is one of the most used actuation mechanisms for the microfluidics in the current active lab-on-chip devices. It is generated on the induced charged microchannel walls in contact with an electrolyte solution. Electrode distribution plays the key role on providing the external electric field for electroosmosis, and determines the performance of electroosmotic microfluidics. Therefore, this paper proposes a topology optimization approach for the electrodes of electroosmotic microfluidics, where the electrode layout on the microchannel wall can be determined to achieve designer desired microfluidic performance. This topology optimization is carried out by implementing the interpolation of electric insulation and electric …

Underwater Communication Acoustic Transducers: A Technology Review, Laila Shams, Tian-Bing Xu, Zhongqing Su (Ed.), Branko Glisic (Ed.), Maria Pina Limongelli (Ed.)

Mechanical & Aerospace Engineering Faculty Publications

This paper provides a comprehensive review on transducer technologies for underwater communications. The popularly used communication transducers, such as piezoelectric acoustic transducers, electromagnetic acoustic transducers, and acousto-optic devices are reviewed in detail. The reasons that common air communication technologies are invalid die to the differences between the media of air and water are addresses. Because of the abilities to overcome challenges the complexity of marine environments, piezoelectric acoustic transducers are playing the major underwater communication roles for science, surveillance, and Naval missions. The configuration and material properties of piezoelectric transducers effects on signal output power, beamwidth, amplitude, and other properties …

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 …

Optical Microresonator-Based Flow-Speed Sensor, Elie Ramon Salameh

Mechanical Engineering Research Theses and Dissertations

Optical sensors have become more prominent in atmospheric measurement systems, with LiDAR instruments deployed on a variety of earth-bound, air-borne, and space-based platforms. In recent years, the interest in the human exploration of Mars has created a substantial push towards reliable and compact sensing elements for Mars exploration missions, particularly during a spacecraft’s entry, descent, and landing stages. Real-time sensors able to reliably measure the craft’s speed relative to the surrounding atmosphere during these stages are thus of great interest. In this dissertation, a proof-of-concept for an optical microfabricated sensor, which leverages the whispering-gallery-mode (WGM) and Doppler shift principles, is …

Effect Of Freestream Noise On Hypersonic Crossflow-Induced Boundary-Layer Transition, Andrew Bustard, Thomas J. Juliano, Harrison B. Yates, Mark Noftz, Joseph Jewell

Publications

Between the windward and leeward rays, boundary-layer transition on cones at angle of attack in hypersonic flow is dominated by the crossflow instability [1, 2], wherein stationary and/or traveling crossflow vortices develop and can breakdown into turbulence [3]. Stationary crossflow modes are caused by surface roughness or any other steady forcing and produce disturbances that are fixed in place on the surface [3–6]. Stationary vortices create a generalized inflection point in the velocity profile that is inviscidly unstable [7]. This distorted mean flow develops secondary instabilities, whose growth and breakdown is one path to turbulence [8–10]. Traveling crossflow modes are …

Measurements Of Wind Turbine Wake Evolution And Trajectory During Morning Boundary Layer Transition And Under Wake Steering Conditions Via Unmanned Aerial Vehicles, Stewart Nelson

Theses and Dissertations--Mechanical and Aerospace Engineering

In July of 2019, a flight campaign was conducted using semi-autonomous Unmanned Aerial Vehicles (UAVs) at the Port Alma Kruger Energy wind farm in Ontario, Canada, to study various aspects of wind turbine wake evolution. Horizontal transects across the wakes were measured using modified fixed-wing aircraft fitted with a five-hole probe to measure the wind velocity vector. Reference boundary layer conditions were measured by an octocopter with an assortment of mounted sensors flying vertical profiles upstream of the turbines. Three experiments were conducted during the campaign, which consisted of a study on wake behavior during the morning boundary layer transition, …

Theoretical Study Of Magnetic Particles In A Shear Flow Subjected To A Uniform Magnetic Field, Christopher A. Sobecki

Doctoral Dissertations

"Magnetic manipulation of non-spherical magnetic microparticles is important for applications in shape-based and magnetic-based separations such as waste management, disease diagnostics, drug delivery, and mining. Manipulations of magnetic microparticles also include chain formation to assemble compositions for electronics, drug loading designs, and magnetorheological fluids for smart armor, hydraulic brakes, and dampers. In microfluidic devices, separation-formation-effectiveness depends on the shape of the channel, the shear rate, and the magnetic field strength and direction.

Particle separation and chain formation involved highly complex and computational expense-demanding studies in microfluidic devices, magnetic fields, and particle- particle/wall interactions. This research took complex experimental studies and …

Field Testing The Effects Of Low Reynolds Number On The Power Performance Of The Cal Poly Wind Power Research Center Small Wind Turbine, John B. Cunningham

Master's Theses

This thesis report investigates the effects of low Reynolds number on the power performance of a 3.74 m diameter horizontal axis wind turbine. The small wind turbine was field tested at the Cal Poly Wind Power Research Center to acquire its coefficient of performance, C­_p, vs. tip speed ratio, λ, characteristics. A description of both the wind turbine and test setup are provided. Data filtration and processing techniques were developed to ensure a valid method to analyze and characterize wind power measurements taken in a highly variable environment. The test results demonstrated a significant drop in the …

Autonomous Watercraft Simulation And Programming, Nicholas J. Savino

Student Scholar Showcase

Automation of various modes of transportation is thought to make travel more safe and efficient. Over the past several decades, advances to semi-autonomous and autonomous vehicles have led to advanced autopilot systems on planes and boats, and an increasing popularity of self-driving cars. We predicted the motion of an autonomous vehicle using simulations in Python. The simulation models the motion of a small scale watercraft, which can then be built and programmed using an Arduino Microcontroller. We examined different control methods for a simulated rescue craft to reach a target. We also examined the effects of different factors, such as …

Microfluidic Biosensor With Functionalized Gold Nano Particles On Interdigitated Electrodes, Bharath Babu Nunna

Dissertations

The integration of the microfluidics to the biosensor has growing demand with favorable conditions such as reduced processing time and low reagent consumption. The immuno biosensing with the microfluidic platform helped to make the electrochemical biosensing assays portable due to which this sensing mechanism can be easily implemented in point of care devices. The implementation of the biosensing in the microchannels significantly reduces the sample requirement form milli liter (mL) to micro liter (uL), and thus leads to low volume sample requirement during the sensing. The primary factors contributing to the microfluidic biosensors performance are probe immobilization, specific binding and …

Design Of Shape-Conforming Nosecone For Optimal Fluid Flow From Transonic To Supersonic Range, Anna Tombazzi

Williams Honors College, Honors Research Projects

Modern flight vehicles, such as rockets, missiles, and airplanes, experience a force caused by forebody wave drag during the flight. This drag force is induced when the frontal point of each vehicle breaks the pressure wave during flight. Efforts to reduce this wave drag force to improve flight efficiency include modifying the nosecone profile of the flight vehicles to lower the drag force.

This project revolved around creating a design to make the transformation of nosecone shapes from a ¾ Parabolic profile to a ½ Power Series profile possible, mid-flight. Using a novel nosecone assembly, shape memory alloys (SMAs) and …

Use Of Single Stage Model Rockets To Teach Some Engineering Principles And Practices To First Year Engineering And Engineering Technology Students, Hüseyin Sarper, Linda Vahala

Electrical & Computer Engineering Faculty Publications

Model rocketry has been called miniature astronautics; a technology in miniature, a hobby, a sport, a technological recreation, an educational tool, and it is all of these things. This paper will describe student projects using model rockets and engines to learn engineering principles for launching rockets and determining the apogee. Model rocketry is a powerful tool for instructors who wish to incorporate science, technology, engineering, and mathematics into a fun, engaging, and challenging activity for first year engineering students. The apogee can be determined using four distinct methods: trigonometry using hand held angle measuring tools, onboard altimeter devices, analytical calculations …

Identification Of Hydrodynamic Forces Developed By Flapping Fins In A Watercraft Propulsion Flow Field, Erdem Aktosun

LSU New Orleans Theses and Dissertations

In this work, the data analysis of oscillating flapping fins is conducted for mathematical model. Data points of heave and surge force obtained by the CFD (Computational Fluid Dynamics) for different geometrical kinds of flapping fins. The fin undergoes a combination of vertical and angular oscillatory motion, while travelling at constant forward speed. The surge thrust and heave lift are generated by the combined motion of the flapping fins, especially due to the carrier vehicle’s heave and pitch motion will be investigated to acquire system identification with CFD data available while the fin pitching motion is selected as a function …

A Shock Tube Technique For Blast Wave Simulation And Studies Of Flow Structure Interactions In Shock Tube Blast Experiments, Nicholas N. Kleinschmit

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Improvised explosive devices (IED’s) are widely used against US and allied forces fighting in Iraq and Afghanistan. Exposure to IED blast may cause blast-induced traumatic brain injury (bTBI). The injury mechanisms are however not well understood. A critical need in bTBI-related research is the ability to replicate the loading conditions of IED blast waves in a laboratory environment. In this work, experimental studies have been carried out to explore the use of the shock tube technique for generating air shock waves that mimic the temporal and spatial characteristics of free-field blast waves and to investigate the blast wave-test sample interactions …

Analytic Confusion Matrix Bounds For Fault Detection And Isolation Using A Sum-Of-Squared-Residuals Approach, Daniel J. Simon, Donald L. Simon

Electrical and Computer Engineering Faculty Publications

Given a system which can fail in 1 of n different ways, a fault detection and isolation (FDI) algorithm uses sensor data to determine which fault is the most likely to have occurred. The effectiveness of an FDI algorithm can be quantified by a confusion matrix, also called a diagnosis probability matrix, which indicates the probability that each fault is isolated given that each fault has occurred. Confusion matrices are often generated with simulation data, particularly for complex systems. In this paper, we perform FDI using sum-of-squared residuals (SSRs). We assume that the sensor residuals are s-independent and Gaussian, which …

Aerodynamic Analysis Of An Urban Magnetic Levitation Vehicle, John Matthew Wells

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis will detail the aerodynamic qualities of a magnetic levitation concept vehicle designed to be installed on Old Dominion University's campus. The vehicle is representative of a class of small, low-speed Maglev systems commonly referred to as Urban Maglev. A 1:12 scale model underwent testing in Old Dominion's low speed wind tunnel. Force and moment coefficients were measured over a wide range of yaw angles. Results give insight into crosswind effects and how these forces affect vehicle dynamics. An analysis of this type is important in understanding the ride quality and safety of the system. Force Coefficients range from …

Multidisciplinary Design Optimization Of An Extreme Aspect Ratio Hale Uav, Bryan J. Morrisey

Master's Theses

ABSTRACT

Multidisciplinary Design Optimization of an Extreme Aspect Ratio HALE UAV

Bryan J. Morrisey

Development of High Altitude Long Endurance (HALE) aircraft systems is part of a vision for a low cost communications/surveillance capability. Applications of a multi payload aircraft operating for extended periods at stratospheric altitudes span military and civil genres and support battlefield operations, communications, atmospheric or agricultural monitoring, surveillance, and other disciplines that may currently require satellite-based infrastructure. Presently, several development efforts are underway in this field, including a project sponsored by DARPA that aims at producing an aircraft that can sustain flight for multiple years and …

Adaptive Control Of A Projectile Fin Using Piezoelectric Elastic Beam, Smitha Mani, Sahjendra N. Singh, Surya Kiran Parimi, Woosoon Yim, Mohamed B. Trabia

Mechanical Engineering Faculty Research

No abstract provided.

Flow Visualization Of A Turbulent Shear Flow Using An Optical Wavefront Sensor, Daniel W. Jewell

Theses and Dissertations

The research reported here investigated the use of a shearing interferometer (SI) wavefront sensor to determine the effects of shear-layer turbulence on an optical wavefront. A collimated helium-neon laser beam was propagated through a plane shear-layer produced by mixing helium and nitrogen at different velocities. Since the gases have different indices of refraction, the optical wavefront was distorted by different amounts by each gas. The SI measured the wavefront slope across the sampled area of the wavefront. The shear-layer was viewed from two orthogonal directions. This document contains shadow graphs, interference patterns imaged by each of the SI's six cameras, …