Mechanical Engineering Commons^™

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 …

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 …

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 …

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 …

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 …

Aerodynamics And Aeroacoustics Optimization Of Vehicle’S Side Mirror Base And Exhaust Pipe, Moath Nayef Mohamed Zaareer

Theses

This thesis is concerned with studying two different vehicle parts in terms of aerodynamics and aeroacoustics. Two main factors determine the efficiency and luxury of the vehicle, the low aerodynamic forces and low noise emission. The aerodynamic drag coefficient is concerned with how easy a vehicle can travel through the air; the lower the value, the less fuel is needed to move the vehicle forward and less air resistance the vehicle faces. The aerodynamic lift coefficient is related to vehicle ground stability, and the more negative the value is, the higher the vehicle's stability. Moreover, the aeroacoustics is concerned with …

Plasma Aerodynamics: Experimental Quantification Of The Lift Force Generated On An Airfoil Using Plasma Actuation To Estimate Power Requirements In Small Uav Applications, Getachew Ashenafi

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research addressed the amount of electric power required to induce specific changes in lift force using a NACA 2127 airfoil with a chord length of ~28 mm, connected to a micro load cell, in a wind tunnel of 103 square centimeter cross-section. A DBD plasma actuator supplied by a ZVS driven high voltage pulsed DC circuit, operating at a frequency of 17.4 kHz, was utilized for voltages of up to 5000 V. Two configurations of electrode gapping were compared to determine the efficient use of power. The configuration with a gap of ~1 mm between the upstream and downstream …

Bicycle Wheel Aerodynamics Predictions Using Cfd: Efficiency Using Blade Element Method, Drew Vigne

Honors Undergraduate Theses

The cycling industry has long relied on expensive wind tunnel testing when designing aerodynamic products, particularly in the context of wheels which account for 10 to 15 percent of a cyclist's total aerodynamic drag. With the recent advent of Computational Fluid Dynamics (CFD), the industry now has an economical tool to supplement the wheel design process; however, the complex nature of rotating spoked wheels requires high resolution meshes to model at acceptable fidelity. This research investigates an alternative CFD method that lowers the computational cost of modeling aerodynamic bicycle wheels by modeling spokes using Blade Element Method (BEM). Two CFD …

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 …

A Study Of The Aeroacoustics Of Swept Propellers For Small Unmanned Aerial Vehicles, Arthur David Wiedemann

Mechanical & Aerospace Engineering Theses & Dissertations

In recent years, small unmanned aerial vehicles (UAVs) have increased in availability and use in both public and commercial sectors. This increased use of small UAVs or “drones” has the unfortunate consequence of introducing excessive noise into communities where they operate. Implementation of noise reduction methods is necessary if we wish to see expanded use of drones in public areas. With electric propulsion, the primary source of noise is the rotor/propeller used in contemporary multi-rotor configurations. In this thesis, the aerodynamics and acoustic behavior of various swept propellers is examined with computational and experimental methods.

A family of propeller geometries …

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 …

Design, Manufacture, And Structural Dynamic Analysis Of A Biomimetic Insect-Sized Wing For Micro Air Vehicles, Jose Enrique Rubio

University of New Orleans Theses and Dissertations

The exceptional flying characteristics of airborne insects motivates the design of biomimetic wing structures that can exhibit a similar structural dynamic behavior. For this purpose, this investigation describes a method for both manufacturing a biomimetic insect-sized wing using the photolithography technique and analyzing its structural dynamic response. The geometry of a crane fly forewing (family Tipulidae) is acquired using a micro-computed tomography scanner. A computer-aided design model is generated from the measurements of the reconstructed scanned model of the insect wing to design the photomasks of the membrane and the venation network required for the photolithography procedure. A composite …

Investigation Of A Novel Turbulence Model And Using Leading-Edge Slots For Improving The Aerodynamic Performance Of Airfoils And Wind Turbines, Saman Beyhaghi

Theses and Dissertations

Because of the problems associated with increase of greenhouse gases, as well as the limited supplies of fossil fuels, the transition to alternate, clean, renewable sources of energy is inevitable. Renewable sources of energy can be used to decrease our need for fossil fuels, thus reducing impact to humans, other species and their habitats. The wind is one of the cleanest forms of energy, and it can be an excellent candidate for producing electrical energy in a more sustainable manner. Vertical- and Horizontal-Axis Wind Turbines (VAWT and HAWT) are two common devices used for harvesting electrical energy from the wind. …

Analysis Of Road Vehicle Aerodynamics With Computational Fluid Dynamics, Christian Armando Mata

Open Access Theses & Dissertations

A road vehicles aerodynamics can be one of the most influential aspects of its performance. With the increased importance on fuel efficiency in recent years, new road vehicles are being developed smaller in size, with smaller displacement engines, as well as with improved aerodynamics. The aerodynamics of a vehicle can have a significant effect on its fuel efficiency, as well as other important aspects of the vehicles performance such as the top speed, acceleration, and handling. A study focusing on analyzing aerodynamic effects due to vehicle geometries such as wheels covered by the vehicles body in comparison to open wheels …

Modal Characterization And Structural Dynamic Response Of A Crane Fly Forewing, Jose E. Rubio

University of New Orleans Theses and Dissertations

This study describes a method for conducting the structural dynamic analysis of a crane fly (family Tipulidae) forewing under different airflow conditions. Wing geometry is captured via micro-computed tomography scanning. A finite element model of the forewing is developed from the reconstructed model of the scan. The finite element model is validated by comparing the natural frequencies of an elliptical membrane with similar dimensions of the crane fly forewing to its analytical solution. Furthermore, a simulation of the fluid-structure interaction of the forewing under different airflows is performed by coupling the finite element model of the wing with a …

Modeling Dynamic Stall For A Free Vortex Wake Model Of A Floating Offshore Wind Turbine, Evan M. Gaertner

Masters Theses

Floating offshore wind turbines in deep waters offer significant advantages to onshore and near-shore wind turbines. However, due to the motion of floating platforms in response to wind and wave loading, the aerodynamics are substantially more complex. Traditional aerodynamic models and design codes do not adequately account for the floating platform dynamics to assess its effect on turbine loads and performance. Turbines must therefore be over designed due to loading uncertainty and are not fully optimized for their operating conditions. Previous research at the University of Massachusetts, Amherst developed the Wake Induced Dynamics Simulator, or WInDS, a free vortex wake …

Aerodynamic Analysis And Drag Coefficient Evaluation Of Time-Trial Bicycle Riders, Peter Nicholas Doval

Theses and Dissertations

Evaluation of drag coefficient often requires wind tunnel experiments and can be prohibitively expensive if not impossible for large objects or systems. Computational Fluid Dynamics (CFD) aerodynamic analysis offers an alternative approach and can be used as a very effective design tool in many industries: automotive, aerospace, marine, etc. The main objective of this research is to investigate feasibility of using non-contact digitizers for developing finite element models of large objects for subsequent CFD analysis. The developed methodology is applied to investigation of time-trial bicycle rider efficiency. Companies competing in this class of racing spend millions trying to optimize bicycle …

Cfd Study On Aerodynamic Effects Of A Rear Wing/Spoiler On A Passenger Vehicle, Mustafa Cakir

Mechanical Engineering Master's Theses

Aerodynamic characteristics of a racing car are of significant interest in reducing car-racing accidents due to wind loading and in reducing the fuel consumption. At the present, modified car racing becomes more popular around the world. Sports cars are most commonly seen with spoilers, such as Ford Mustang, Subaru Impreza, and Chevrolet Corvette. Even though these vehicles typically have a more rigid chassis and a stiffer suspension to aid in high-speed maneuverability, a spoiler can still be beneficial. One of the design goals of a spoiler is to reduce drag and increase fuel efficiency. Many vehicles have a fairly steep …

Analysis Of Wake Vortices Of A Medium Range Twin-Propeller Military Cargo Aircraft Using Statistically Designed Experiments, Burhan Sahin

Mechanical & Aerospace Engineering Theses & Dissertations

An experimental study was initiated to analyze the trajectories of the streamwise vortices behind the wing tip and flap of a medium range and propeller driven twin-engine military cargo aircraft. The model used for the experimental study was a generic, high wing and half model of a propeller driven aircraft and mounted within Old Dominion University's Low Speed Wind Tunnel where the wind tunnel flow speed was set to constant value of 9 m/sec. The main purpose of the study was to reach regression models for the motion and vorticity strength of both vortices under varying factors such as angle …

A System For Measuring The Lift And Drag Forces Of A Spinning Golf Ball Held Fixed Within A Wind Tunnel, Ryan R. Miller

Master's Theses

A system was designed, built and tested in order to test the aerodynamic properties of a standard golf ball in a wind tunnel manufactured by ELD, Inc. model 406(B). The system consists of a rotating shaft, on which the golf ball is attached, connected to a two-axis force transducer. Additionally, an automated data acquisition system was built for enhanced precision of measurements. Data for wind speeds up to 160 ft/s and rotational speeds up to 8,600 rpm were obtained and analyzed. The purpose of the designed apparatus was to allow for studies to better understand the lift and drag coefficients …

Alleviation Of Buffet-Induced Vibration Using Piezoelectric Actuators, Shawn D. Morganstern

Theses and Dissertations

Buffet-induced vibration has been problematic for aircraft structures for many years. The F-16 ventral fin, while prone to these effects, lends itself well to the evaluation of modern active structural and flow control technologies. The objective of this research was to determine the most critical natural modes of vibration for the F-16 ventral fin and design piezoelectric actuators capable of reducing buffet-induced ventral fin vibration. A finite element model (FEM) for the fin was developed, tuned and optimized to closely match published modal frequencies. Piezoelectric actuator patches were designed using the strain characteristics of the FEM and integrated into the …

External Aerodynamics Of Heavy Ground Vehicles: Computations And Wind Tunnel Testing, Ilhan Bayraktar

Mechanical & Aerospace Engineering Theses & Dissertations

Aerodynamic characteristics of a ground vehicle affect vehicle operation in many ways. Aerodynamic drag, lift and side forces have influence on fuel efficiency, vehicle top speed and acceleration performance. In addition, engine cooling, air conditioning, wind noise, visibility, stability and crosswind sensitivity are some other tasks for vehicle aerodynamics. All of these areas benefit from drag reduction and changing the lift force in favor of the operating conditions. This can be achieved by optimization of external body geometry and flow modification devices. Considering the latter, a thorough understanding of the airflow is a prerequisite.

The present study aims to simulate …

Boundary Layer Influences On The Subsonic Near-Wake Of A Family Of Three-Dimensional Bluff Bodies, Charles Willliam Alcorn

Mechanical & Aerospace Engineering Theses & Dissertations

A study is reported on subsonic bluff body near-wake flows. It has been determined that one family of bluff bodies, namely slanted-base ogive cylinders, can experience either a closed recirculating near-wake, or a longitudinal vortex near-wake depending on the base slant-angle and the Reynolds number. This suggests a dependence of near-wake parameters on the state of the boundary layer ahead of separation. This report addresses the influence of the boundary layer on the near-wake of slanted-base bluff bodies. Experiments were conducted in two facilities, the 6-inch Magnetic Suspension and Balance System (MSBS) at NASA Langley Research Center and the Old …