Aerospace Engineering Commons^™

Nonlinearity Index Aircraft Spin Motion Analysis With Dynamic Inversion Spin Recovery Controller Design, Jeffry Walker

Mechanical & Aerospace Engineering Theses & Dissertations

The aim of this thesis research is to extend the previous work of Tapolcai utilizing nonlinearity index theory to quantitatively analyze nonlinearities in an aircraft model and to augment these undesirable nonlinear characteristics with feedback control. In his work Tapolcai utilized a simplified rotational three degree of freedom model to analyze spin conditions of the F-18 High Angle-of-Attack Research Vehicle model. Through the application of nonlinearity index theory, regions of severe nonlinearity were uncovered exhibiting chaotic non-periodic behavior, periodic limit cycling, and instability. If these conditions were encountered during flight, the aircraft would exhibit undesirable response characteristics thereby requiring augmented …

Cfd Simulations Of A Propeller-Wing Interaction, Asim Oktay Akdeniz

Mechanical & Aerospace Engineering Theses & Dissertations

In this study, 3-D turbulent flows around a propeller driven aircraft model placed in a subsonic wind tunnel were computationally simulated for qualitative investigation of near field wakes. The geometry of the model was created using commercial mesh generation software, GRIDGEN, and then simulations were performed using a commercial finite volume Reynolds-Averaged Navier-Stokes (RANS) solver FLUENT.

Initial runs were performed to validate the boundary conditions and setup of the problem where a hybrid mesh consisting of multi-blocks was in use. Sliding mesh concept used in the computations. Laminar flow simulation have been utilized and tested besides Spalart-Allmaras and k-ω SST …

Dynamic And Control Of Air-Bearing Spacecraft Simulator, Jacob Joseph Korczyk

Doctoral Dissertations and Master's Theses

An air bearing is being designed as a spacecraft rotational motion simulator, featuring the Sawyer Robot and its control box. The objective is to maneuver the robot as desired, performing operations specific to on-orbit servicing operations while maintaining stability of the system. Before the control can be designed, the dynamics of the platform and the robot must be modeled. The dynamics of the robot can be derived utilizing a Newton-Euler recursive approach. By beginning with a simple pendulum, then adding links (degrees of freedom) to more closely resemble the Sawyer arm, the equations of motion for the robot can be …

Numerical Investigation Of Leading-Edge Modifications Of A Naca Airfoil, Anisur Rahman Ikram

Masters Theses

A parametric investigation was carried out to understand the flow characteristics of tubercle airfoils and to determine the best approach and parameters for designing a tubercle airfoil. For this purpose, a straight edge base airfoil (NACA 4414) and several tubercle airfoils, by modifying the leading edge of the base airfoil, were created in SolidWorks and tested with Computational Fluid Dynamics (CFD) application software Star CCM+.

Alternative tubercle airfoil with elliptical bumps demonstrated superior post-stall performance when compared to their straight edge counterparts; their post-stall lift did not decrease drastically. However, their pre-stall lift coefficients were always lower than the base …

Hybrid Non-Destructive Assessment For Flow Induced Vibration Piping Systems Using Coupled Fluid-Structure Interaction, Keen Kuan Kong

Student Works (2020-2029)

Pipelines and piping systems are of great importance in many industries such as water supply, petroleum and petrochemicals and nuclear power generation. They provide transport for high-velocity pressurized fluids operating under time-varying conditions. They are required to operate non-stop for a schedule of 24 hours a day, 7 days a week. Piping vibration failures have been one of the major causes of downtime, fires and explosions in industrial plant over the past 30 years. Failure of piping systems can have disastrous effects, leading to injuries and fatalities as well as to substantial cost to industry and the environment. Flow-induced vibration …

Design And Control Of An Arrayed Infrared (Mat-Ir) Heater For Accurate Heating Control During Automated Fiber Placement, Benjamin L. C. Greenberg

Theses and Dissertations

Automated Fiber Placement (AFP) is the primary method for manufacturing of large and complex primary composite structures in the aerospace industry. Predominantly, AFP use infrared heaters to ensure appropriate tackiness between the different composite layers. The task of accurately detecting and obtaining a set uniform temperature, across the nip point/line, has proven to be difficult. Traditional AFP heat processes are mostly open-loop controlled, which can lead to issues with ensuring accurate and uniform heat distributions. The latter need to be obtained to allow for proper material consolidation to occur. Uneven heating could cause degradation at the center or at the …

Automation Of Process Planning For Automated Fiber Placement, Joshua A. Halbritter

Theses and Dissertations

Process planning represents an essential stage of the Automated Fiber Placement (AFP) workflow. It develops useful and efficient machine processes based upon the working material, composite design, and manufacturing resources. The current state of process planning requires a high degree of interaction from the process planner and could greatly benefit from increased automation. Therefore, a list of key steps and functions are created to identify the more difficult and time-consuming phases of process planning. Additionally, a set of metrics must exist by which to evaluate the effectiveness of the manufactured laminate from the machine code created during the Process Planning …

A Post-Impact Behavior Of Platelet-Based Composites Produced By Compression Molding, Christopher Eugene Ervin Volle

Mechanical & Aerospace Engineering Theses & Dissertations

Prepreg-based Platelet Molded Compounds (PPMCs) are quickly becoming a widely used method for creating structural components in the aerospace and automotive industries. The discontinuous nature of the platelets used allow good formability of both complex and basic structural components; from seats on commercial airplanes to outer panels of vehicles.

This thesis will look at an important research question of these composites: how PPMCs behave under dynamic loading, e.g. impact and post-impact behavior. Impact is analyzed using recorded force and velocity data to find the absorbed energy. Digital image correlation is used with compression after impact testing to study the propagation …

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 …

Analysis Of Training Programs For The Training Of Air Traffic Controllers For Determining The Field Of Digitization, Sabohat Shukurova, Z.Z. Shamsiev, A. Sterenharz

Technical science and innovation

The article emphasizes the high demands that are put forward to the professional knowledge and skills of air traffic controllers. Attention is drawn to ICAO's civil aviation training policy, which supports the human resource development strategies developed by Member States and the aviation community and provides access to a sufficient number of qualified and competent professionals. Based on this, the feasibility of research and improvement of the educational process of training air traffic controllers is substantiated. As a research method, the collection, processing and analysis of statistical data is used. As the subject of the study, educational programs for the …

Launch Vehicle Design For The Far-Mars Competition, Matthew Boban, Bryce Smoldon, Jonathan Noble, Stefan Johnson, Maxwell Kauker, Nicholas Wright, Andrew Lucka

Discovery Day - Prescott

Zenith Propulsion is constructing a launch vehicle, named Altair, to compete in a competition hosted by the Friends of Amateur Rocketry (FAR) and the Mars Society. The objective for Zenith Propulsion is to design, build and launch Altair to a qualifying altitude of 30,000 feet in the FAR-Mars competition. Altair will utilize a rocket engine that has been in development at Embry-Riddle Aeronautical University’s Prescott campus since late 2018. This engine, named Janus, uses liquid oxygen and Jet-A and is designed to deliver 1000 lbf of thrust. Altair will be launched from the FAR launch site, in Mojave, CA, on …

Space And Defense – Volume Eleven – Number One – Spring 2019, Space And Defense Journal

Space and Defense

No abstract provided.

Space And Defense – Volume Nine – Number One – Spring 2016, Space And Defense Journal

Space and Defense

No abstract provided.

Space And Defense – Volume Eight – Number One – Spring 2015, Space And Defense Journal

Space and Defense

No abstract provided.

Space And Defense – Volume Seven – Number One – Winter 2014, Space And Defense Journal

Space and Defense

No abstract provided.

Space And Defense – Volume Six – Number One – Fall 2012, Space And Defense Journal

Space and Defense

No abstract provided.

Space And Defense – Volume Five – Number One – Summer 2011, Space And Defense Journal

Space and Defense

No abstract provided.

Space And Defense – Volume Four – Number Two – Summer 2010, Space And Defense Journal

Space and Defense

No abstract provided.

Space And Defense – Volume Four – Number One – Winter 2010, Space And Defense Journal

Space and Defense

No abstract provided.

Space And Defense – Volume Three – Number Two – Fall 2009, Space And Defense Journal

Space and Defense

No abstract provided.