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Articles 1 - 30 of 200
Full-Text Articles in Engineering
Ductape: A Steady-State, Axisymmetric Ducted Fan Analysis Code Designed For Gradient-Based Optimization, Judd Mehr, Andrew Ning
Ductape: A Steady-State, Axisymmetric Ducted Fan Analysis Code Designed For Gradient-Based Optimization, Judd Mehr, Andrew Ning
Faculty Publications
Electric ducted fans have become an intriguing option for the propulsion systems of clean, quiet advanced air mobility technologies due to their potential benefits in both aerodynamic efficiency and reduced noise profiles compared to open rotor systems. Exploration of conceptual electric ducted fan design in the context of novel, and often complex, applications may be greatly aided by the use of optimization techniques. Specifically, gradient-based optimization lends itself to the exploration of large, complex, multi-disciplinary systems due to its inherent scalability. Despite ducted fans/propellers having been relatively well studied for the last century, modern, gradient-based, optimization-ready analysis tools for ducted …
3d-Printed Remote Controlled Aircraft, Sebastian Bessoudo, Jose Ramirez, Manny Ruiz, Andrew Edwards
3d-Printed Remote Controlled Aircraft, Sebastian Bessoudo, Jose Ramirez, Manny Ruiz, Andrew Edwards
Mechanical Engineering
The Senior Project for the 3D Printed Aircraft presents a compelling challenge to the team: design and fabricate an aircraft for the Cal State LA 3D-Printed Fixed-Wing Aircraft Competition, comprising three distinct events: Flight, Design, and Simulation. The objective of the flight competition is to achieve the longest flight duration, while the design event emphasizes innovation and originality. In the Simulation contest, our aircraft's CAD model undergoes Computational Fluid Dynamics analysis to assess its aerodynamic performance. These competitions are slated for May 2024.
While building the aircraft has its limitations due to the source of our construction being only 3D …
Modeling Of Rotor Wake Vortex Dynamics And Interactions In Non-Homogenous Vertiport Environments, Garrison P. Shaw
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 …
Aerodynamic Design And Analysis Of A Modified 2006 Mazda Miata, William N. Recher
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 …
Development Of Eagle3d Solver For Wall Modeled Les Of Transonic Flows, Spencer Moore
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 …
Winglet Vortex Optimization, Adeel Khalid, Anthony Gutierrez
Winglet Vortex Optimization, Adeel Khalid, Anthony Gutierrez
The Kennesaw Journal of Undergraduate Research
The objective of this research is to determine the effect on aerodynamic performance due to changes of winglet design variables 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 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 efficiency through …
Uav To Carry Heavy Loads, Jacob Cannon, Robert Connor Downs, Anthony Orlando
Uav To Carry Heavy Loads, Jacob Cannon, Robert Connor Downs, Anthony Orlando
Williams Honors College, Honors Research Projects
Our senior design project aims to develop an innovative Unmanned Aerial Vehicle (UAV) capable of carrying heavy payloads up to 50 lbs. This UAV will address the growing demand for efficient and autonomous cargo transportation, unlocking new possibilities in logistics and remote deliveries. The primary goal is to design, build, and test a robust UAV platform equipped with advanced propulsion systems, stabilizing mechanisms, and a secure payload attachment system. The heavy-lift UAV will be capable of transporting payloads in challenging environments, enhancing its versatility for various industries, including emergency response, disaster relief, and commercial logistics. For the extent of this …
Numerical Study Of Owls' Leading-Edge Serrations, Asif Shahriar Nafi, Nikolaos Beratlis, Elias Balaras, Roi Gurka
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 …
Estimated Aerodynamic Forces And Moments And Optimal Orientation Of The V-Bat Airframe During Vertical Landing In Gusty Conditions, Parker C. Carter
Estimated Aerodynamic Forces And Moments And Optimal Orientation Of The V-Bat Airframe During Vertical Landing In Gusty Conditions, Parker C. Carter
All Graduate Theses and Dissertations, Fall 2023 to Present
Ship based Unmanned Air Systems (UAS) are an important tool used by the United States Navy for situational awareness and short-range operations. Naval UAS are used to provide real-time intelligence, surveillance, reconnaissance, and target-acquisition while being low cost, mission flexible, and safe. Unfortunately UAS suffer disadvantages with respect to adverse environmental conditions caused by the air being displaced by the ship. The accumulation of one or more adverse conditions is known as airwake. To counteract the effects of airwake, the objectives of this work are to first evaluate the effect of forces and moments during the vertical landing phase of …
Development, Implementation, And Optimization Of A Modern, Subsonic/Supersonic Panel Method, Cory D. Goates
Development, Implementation, And Optimization Of A Modern, Subsonic/Supersonic Panel Method, Cory D. Goates
All Graduate Theses and Dissertations, Fall 2023 to Present
In the early stages of aircraft design, engineers consider many different design concepts, examining the trade-offs between different component arrangements and sizes, thrust and power requirements, etc. Because so many different designs are considered, it is best in the early stages of design to use simulation tools that are fast; accuracy is secondary. A common simulation tool for early design and analysis is the panel method. Panel methods were first developed in the 1950s and 1960s with the advent of modern computers. Despite being reasonably accurate and very fast, their development was abandoned in the late 1980s in favor of …
Parametric Optimization Of A Wing-Fuselage System Using A Vorticity-Based Panel Solver, Chino Cruz
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 …
Development Of Load Measurement Technique For Arbitrary Shapes, Quintin J. Cockrell
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. …
Aerodynamic & Aeroacoustic Performance Of Wind Turbine Blades Featuring Enhanced Flow-Control, Md Zishan Akhter
Aerodynamic & Aeroacoustic Performance Of Wind Turbine Blades Featuring Enhanced Flow-Control, Md Zishan Akhter
Dissertations
Wind energy, being one of the cleanest and most sustainable sources, has undergone remarkable growth in recent years due to advancements in aerodynamics and increased power output. The research community is actively pursuing the development of cutting-edge solutions to further optimize wind turbine technology, ensuring its maximum efficiency and revolutionizing the landscape of wind power.
This research aims to design and develop flow-control devices for wind turbine blades, employing both active and passive control mechanisms, namely morphing trailing-edge and slot-profile, respectively. The objective is to enhance wind turbine performance across a wide range of wind speeds. The morphing trailing-edge mechanism …
Augmenting External Surface Pressures’ Predictions On Isolated Low-Rise Buildings Using Cfd Simulations, Md Faiaz Khaled, Aly Mousaad Aly
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 …
Numerical Study Of Flow Characteristics Around A 30° Yawed Circular Cylinder At R E = 10 4, Ran Wang, Shaohong Cheng, David S.K. Ting
Numerical Study Of Flow Characteristics Around A 30° Yawed Circular Cylinder At R E = 10 4, Ran Wang, Shaohong Cheng, David S.K. Ting
Civil and Environmental Engineering Publications
Unstable motions of bridge stay cables have been observed on site and in wind tunnel tests when a cable is yawed at certain orientations to wind. To uncover the underlying mechanisms, flow around a circular cylinder at a yaw angle of 30° has been numerically analyzed in the current study using delayed detached eddy simulation (DDES) at R e = 10 4 . A comparison with the reference normal flow case indicates the presence of a more coherent span-wise flow structure when the cylinder is yawed at 30°. The application of proper orthogonal decomposition further reveals that at this orientation, …
Faster, Cheaper, And Better Cfd: A Case For Machine Learning To Augment Reynolds-Averaged Navier-Stokes, John Peter Romano Ii
Faster, Cheaper, And Better Cfd: A Case For Machine Learning To Augment Reynolds-Averaged Navier-Stokes, John Peter Romano Ii
Mechanical & Aerospace Engineering Theses & Dissertations
In recent years, the field of machine learning (ML) has made significant advances, particularly through applying deep learning (DL) algorithms and artificial intelligence (AI). The literature shows several ways that ML may enhance the power of computational fluid dynamics (CFD) to improve its solution accuracy, reduce the needed computational resources and reduce overall simulation cost. ML techniques have also expanded the understanding of underlying flow physics and improved data capture from experimental fluid dynamics.
This dissertation presents an in-depth literature review and discusses ways the field of fluid dynamics has leveraged ML modeling to date. The author selects and describes …
Aerodynamic Flow Control Using Micro Rotating Cylinders, Alejandro Daniel Carrizales
Aerodynamic Flow Control Using Micro Rotating Cylinders, Alejandro Daniel Carrizales
Theses and Dissertations
This research investigates the aerodynamic and flow field characteristics of a NACA 0010 airfoil equipped with rotating cylinders near the leading edge, subjected to a flow with a freestream turbulence intensity of 4.3%. The airfoil was modified to integrate five micro-DC motors positioned at 14.5% of the chord length from the leading edge. The cylinders, with dimensions of 0.75 inches in diameter and 0.5 inches in width, exposed 3mm of their length to the incoming flow. A modified leading edge with eight sinusoidal protrusions (tubercles) was employed to compare the performance of the micro-rotating cylinder airfoil with an unmodified baseline …
Stabilization Trajectory And Recovery System For High Altitude Weather Balloon Payloads (S.T.A.R.), Robert Canalas, Aaron Juan, Miles Nguyen, James Oblitas, Anne Paloma
Stabilization Trajectory And Recovery System For High Altitude Weather Balloon Payloads (S.T.A.R.), Robert Canalas, Aaron Juan, Miles Nguyen, James Oblitas, Anne Paloma
Mechanical Engineering Senior Theses
Of the 657,000 global balloon launches each year, only 20% of payloads are recovered, leading to unsustainable business and environmental practices. This paper details the development and evaluation of the S.T.A.R. (Stabilization, Trajectory, and Recovery) system, which increases the recovery rate of weather balloon sensors by enabling ideal landing conditions. System testing concludes that S.T.A.R. is capable of housing weather sensors in a fully controllable glider capable of targeted landing. If properly scaled up and redesigned for mass production, the S.T.A.R. system increases weather-sensing equipment recovery for weather-reporting institutions around the world. Although the featured iterations consist of basswood, carbon …
Vortex Particle Method For Electric Ducted Fan In Non-Axisymmetric Flow, Eduardo Alvarez, Cibin Joseph, Andrew Ning
Vortex Particle Method For Electric Ducted Fan In Non-Axisymmetric Flow, Eduardo Alvarez, Cibin Joseph, Andrew Ning
Faculty Publications
The vortex particle method has been reformulated in recent work as a large eddy simulation (LES) in a scheme that is both meshless and numerically stable, solving long-standing issues of numerical stability. In this study, we build upon this meshless LES scheme to create a simulation framework for electric ducted fans. This poses the challenge of introducing solid boundaries in the vorticity form of the Navier-Stokes equations without a mesh. Rotor blades are introduced in our computational domain through an actuator line model (ALM) following well-established practices for LES. A novel, vorticity-based, actuator surface model (ASM) is developed for the …
Aerodynamic Implications Of A Bio‐Inspired Rotating Empennage Design For Control Of A Fighter Aircraft, Christian R. Bolander
Aerodynamic Implications Of A Bio‐Inspired Rotating Empennage Design For Control Of A Fighter Aircraft, Christian R. Bolander
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
This dissertation presents an analysis of the aerodynamics for an aircraft using a novel, bio-inspired control system. The control system is a rotating tail, that is inspired by the way in which birds use their tail to control their flight. An aerodynamic model for a baseline aircraft and a bio-inspired variant are created by referencing well-known relationships for the aerodynamics of flight, which are then used to analyze the available flight envelope at which each aircraft can reach two different equilibrium states. An analysis of the total aerodynamic control authority of each aircraft is also included along with a preliminary …
Innovation For The Air: A Brief History Of Worldwide Aviation, Lauren Plumley
Innovation For The Air: A Brief History Of Worldwide Aviation, Lauren Plumley
Honors Theses
The purpose of this report is to present a brief but comprehensive overview of the variety of innovations related to aviation, and to discuss their impact on scientific progress over the course of human history. Relevant discoveries from the fields of physics and aerodynamics, and the numerous technologies built based upon these discoveries, are discussed over a period ranging from ancient times to the twenty-first century. The scope of this report is an overview of the development of powered and unpowered aircraft, including lighter-than-air, heavier-than-air, and aerospace technologies. Aviation developments were generally not limited to one specific country or person, …
The Influence Of Surface Roughness Frequency On Rotating Sphere Aerodynamics, Jack C. Elliott
The Influence Of Surface Roughness Frequency On Rotating Sphere Aerodynamics, Jack C. Elliott
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Solving the problems of increasing highway fuel efficiency, throwing a better curve ball, and preventing an aircraft from stalling all have a common thread: controlling flow separation. Defined by the fast moving flow around an object detaching from the object, flow separation has implications for a broad number of engineering fields. Research regarding flow separation control has led to the understanding that the easiest method for delaying flow separation for a given shape is to vary how turbulent the flow around the object is. Varying this turbulence around an object may be achieved through various methods including changing the …
Prediction & Active Control Of Multi-Rotor Noise, Samuel O. Afari
Prediction & Active Control Of Multi-Rotor Noise, Samuel O. Afari
Doctoral Dissertations and Master's Theses
Significant developments have been made in designing and implementation of Advanced Air Mobility Vehicles (AAMV). However, wider applications in urban areas require addressing several challenges, such as safety and quietness. These vehicles differ from conventional helicopter in that they operate at a relatively lower Reynolds number. More chiefly, they operate with multiples of rotors, which may pose some issues aerodynamically, as well as acoustically. The aim of this research is to first investigate the various noise sources in multi-rotor systems. High-fidelity simulations of two in-line counter-rotating propellers in hover, and in forward flight conditions are performed. Near field flow and …
Jet Noise Reduction: A Fresh Start, Christopher K. Tam, Fang Q. Hu
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. …
Design And Validation Of An Aerodynamic System For A Formula Sae® Vehicle Using Vehicle Dynamic Simulation And Experimentation, Evan S. Cole
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
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 …
Feasibility Study Of Slotted, Natural-Laminar-Flow Airfoils For High-Lift Applications, Hector David Ortiz Melendez
Feasibility Study Of Slotted, Natural-Laminar-Flow Airfoils For High-Lift Applications, Hector David Ortiz Melendez
Doctoral Dissertations
A computational fluid dynamics approach to evaluate the feasibility of a slotted, natural-laminar-flow airfoil designed for transonic applications, to perform as a high-lift system was developed. Reynolds-Averaged Navier-Stokes equations with a laminar-turbulent transition model for subsonic flow at representative flight conditions were used for this analysis. Baseline high-lift simulations were performed to understand the stall characteristics of the slotted, natural-laminar-flow airfoil. Maximum aerodynamic efficiency was observed with a constant slot-width. In addition, the effectiveness of the aft-element as a high-lift device was explored. Results indicate that a micro-flap is a viable option as a lift effector. These are most effective …
Meshless Large Eddy Simulation Of Propeller-Wing Interactions With Reformulated Vortex Particle Method, Eduardo Alvarez, Andrew Ning
Meshless Large Eddy Simulation Of Propeller-Wing Interactions With Reformulated Vortex Particle Method, Eduardo Alvarez, Andrew Ning
Faculty Publications
The vortex particle method (VPM) has gained popularity in recent years due to a growing need to predict complex aerodynamic interactions during preliminary design of electric multirotor aircraft. However, VPM is known to be numerically unstable when vortical structures break down close to the turbulent regime. In recent work, the VPM has been reformulated as a large eddy simulation (LES) in a scheme that is both meshless and numerically stable, without increasing its computational cost. In this study, we build upon this meshless LES scheme to create a solver for interactional aerodynamics. Rotor blades are introduced through an actuator line …
Large Eddy Simulations Of Wind Shear From Passing Vehicles Under A Freeway Overpass, Hamid Rahai, Assma Begum
Large Eddy Simulations Of Wind Shear From Passing Vehicles Under A Freeway Overpass, Hamid Rahai, Assma Begum
Mineta Transportation Institute
California is moving toward a 100% clean energy future, and expanded wind energy will be a major component of the state’s future energy portfolio. Innovations in wind energy resources will move California closer to achieving its goal. To gain a better understanding of transient pressure and the wind shear generated at the bridge poles from passing vehicles, this study performed large-eddy simulations of a vehicle (also called an Ahmed body) moving under a freeway overpass at a distance of 0.75 w (width) from the bridge poles. Results include transient contours of mean velocity, turbulent kinetic energy, vorticity, and pressure around …
Effects Of Rotor-Airframe Interaction On The Aeromechanics And Wake Of A Quadcopter In Forward Flight, Denis-Gabriel Caprace, Andrew Ning, Philippe Chatelain, Grégoire Winckelmans
Effects Of Rotor-Airframe Interaction On The Aeromechanics And Wake Of A Quadcopter In Forward Flight, Denis-Gabriel Caprace, Andrew Ning, Philippe Chatelain, Grégoire Winckelmans
Faculty Publications
From small drones to large Urban Air Mobility vehicles, the market of vertical take-off and landing (VTOL) aircraft is currently booming. Modern VTOL designs feature a variety of configurations involving rotors, lifting surfaces and bluff bodies. The resulting aerodynamics are highly impacted by the interactions between those components and their wakes. This has consequences on the aircraft performance and on the downstream wake. Studying the effects of those interactions through CFD can inform the development of cheaper numerical models. In this work, we focus on the interaction between rotors and bluff bodies based on the example of a generic quadcopter …
Foundations For Finite-State Modelling Of A Two-Dimensional Airfoil That Reverses Direction, Jake Michael Oscar Welsh
Foundations For Finite-State Modelling Of A Two-Dimensional Airfoil That Reverses Direction, Jake Michael Oscar Welsh
McKelvey School of Engineering 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 …