Aerospace Engineering Commons^™

Calibration And Characterization Of Cubesat Magnetic Sensors Using A Helmholtz Cage, Justin Dean Foley

Master's Theses

Small satellites, and CubeSats in particular, have quickly become a hot topic in the aerospace industry. Attitude determination is currently one of the most intense areas of development for these miniaturized systems and future Cal Poly satellite missions will depend heavily on magnetometers. In order to utilize magnetometers as a viable source of attitude knowledge, precise calibration is required to ensure the greatest accuracy achievable. This paper outlines a procedure for calibrating and testing magnetometers on the next generation of Cal Poly CubeSates, utilizing a Helmholtz cage to simulate any desired orbital magnetic field that would be experienced by a …

Manufacturing Processes In An All-Aluminum Airframe, Stewart Mcdougall

Aerospace Engineering

One often overlooked aspect to building an aircraft is the manufacturing process used to put it into production. This may be a major contributor to acquisition cost and requires a large amount of money to implement. Once all the tooling has been purchased, one of the greatest costs is labor. The experience of building an all-aluminum aircraft shows that the production process is one which may be done in many different ways. Minimizing the assembly time is important for aircraft manufacturers and one of the best ways to do that is on the assembly line itself. Specific practices in the …

Determination Of Human Powered Helicopter Stability Characteristics Using Multi-Body System Simulation Techniques, Sean M. Brown

Master's Theses

Multi-Body System Simulation combined with System Identification was developed as a method for determining the stability characteristics of a human powered helicopter(HPH) configurations. HPH stability remains a key component for meeting competition requirements, but has not been properly treated. Traditional helicopter dynamic analysis is not suited to the HPH due to its low rotation speeds and light weight. Multi-Body System Simulation is able to generate dynamic response data for any HPH configuration. System identification and linear stability theory are used to determine the stability characteristics from the dynamic response. This thesis focuses on the method development and doesn't present any …

Optimizing The Mechanical Characteristics Of Bamboo To Improve The Flexural Behavior For Biocomposite Structural Application, Jay Lopez

Master's Theses

Global awareness and preservation have spurred increasing interest in utilizing environmentally friendly materials for high-performance structural applications. Biocomposites pose an appealing solution to this issue and are characterized by their sustainable lifecycles, biodegradable qualities, light weight, remarkable strength, and exceptional stiffness. Many of these structural qualities are found in applications that exhibit flexural loading conditions, and this study focuses on improving the bending performance of engineered biocomposite structures. The current application of biocomposites is increasing rapidly, so this expanding research explores other natural constituent materials for biocomposite structures under flexural loading.

The renewable material investigated in this study was experimentally …

Mechanical Optimization And Buckling Analysis Of Bio-Composites, Cameron D. Chan

Master's Theses

Today’s environmental concerns have led a renewed search in industry to find new sustainable materials to replace non-renewable resources. President Barack Obama also quoted in the recent 2012 Presidential Debate “that there is a need to build the energy sources of the future and invest in solar, wind, and bio-fuels.” Bio-composites are believed to be the future and the new substitute for non-renewable resources. Bio-composites are similar to composites in that they are made up of two constituent materials; however the main difference is that bio-composites are made from natural fibers and a biopolymer matrix. This research investigates the buckling …

Validation Of The Ballistic Limit Equation For Monolithic Aluminum Shielding At Geostationary Orbital Debris Impact Velocity, Brandon Holladay

Aerospace Engineering

The Cal Poly Electro Magnetic Rail Gun was used to eject a 0.370 gram, rectangular aluminum projectile towards a 1/16 inch monolithic aluminum plate at a speed of 280 ± 50 m/s. The resulting impact left a large attached spall on the back of the shielding. The impact damage was compared to an industry ballistic limit equation for a spherical aluminum projectile of similar diameter and was shown to have slightly less damage than the expected results.

In addition, an aluminum mesh double bumper shield was fired upon in order to verify its higher protection per aerial density as well …

Three-Axis Stabilized Earth Orbiting Spacecraft Simulator, Alan F. Ma, Nikola N. Dominikovic

Aerospace Engineering

This report details the method and results of the program created for simulating an Earth orbiting spacecraft with control actuators and orbital perturbations. The control actuators modeled are reaction thrusters, reaction/momentum wheels, and control moment gyros (CMG). The perturbations modeled were gravity gradient, electromagnetic torques, solar radiation pressure, gravity gradients, third-body effects, Earth oblateness and atmospheric drag. This simulation allows for satellite control in all 6 degrees of freedom for any Earth orbiting spacecraft. Assumptions include rigid body dynamics, no sensor noise, constant spacecraft cross-sectional area, constant coefficient of drag and reflectivity, ignoring the effects due to the moon, moment …

Fundamental Sizing Implications Of Constant Or Increasing Weight Aircraft, Robert A. Mcdonald

Aerospace Engineering

As the energy storage capabilities of batteries and fuel cells advance, these technologies are increasingly being considered for aircraft primary propulsion. In addition to other fundamental differences from conventional systems, these concepts may have constant or even increasing mass throughout the mission. In this paper, the implications of constant or increasing mass on aircraft sizing are considered with the aim of generating insight for the design of these systems.

Performance Effects Of Damage Arrestment Devices On Sandwich Composite Beams Under Monotonic Loading, Yvette Vanessa Wood

Aerospace Engineering

Face-core delamination has become a subject matter in the Aerospace industry, as it can lead to early failure. In this study, sandwich composite beams are tested initially with no delamination to obtain the ultimate strength. A second case of delamination in the center of the beam in initialized to verify a decrease in ultimate strength. This experiment investigates the performance effects of the addition of Damage Arrestment Devices (DADs), in composite sandwich beams. The performance criterion is measured by strength in flexural loading test. The objective of this project is to verify an increase in the strength and performance with …

Optimal Slewing Of A Constrained Telescope Using Seventh Order Polynomial Input Torques, Julia K. Bush

Master's Theses

Two-axis gimbals are frequently used to point cameras and telescopes at various points of interest for surveillance, science, and art. The rotation of a two-axis gimbal system is governed by nonlinear angular momentum equations of motion. This paper presents a method for slewing a telescope in space with a gimbaled sensor attached to a nominally non-rotating spacecraft using two seventh order polynomial input functions to characterize torques. To accomplish this task, picking the optimal coefficients of the seventh order polynomial was necessary. It was also desired to use constraint equations to limit the excursion, angular velocity, angular acceleration, and jerk …

Analysis Of A Goldschmied Propulsor Using Computational Fluid Dynamics Referencing California Polytechnic's Goldschmied Propulsor Testing, Cory A. Seubert

Master's Theses

The Goldschmied Propulsor is a concept that was introduced in mid 1950's by Fabio Goldschmied. The concept combines boundary layer suction and boundary layer ingestion technologies to reduce drag and increase propulsor efficiency. The most recent testing, done in 1982, left questions concerning the validity of the results. To answer these questions a 38.5in Goldschmied Propulsor was constructed and tested in Cal Poly's 3x4ft wind tunnel. The focus of their wind tunnel investigation was to replicate Goldschmied's original testing and increase the knowledge base on the subject. The goal of this research was to create a computational fluid dynamics (CFD) …

An Alternative Dual-Launch Architecture For A Crewed Asteroid Mission, Steven M. Korn

Master's Theses

This thesis is a feasibility study for a crewed mission to a Near Earth Asteroid (NEA). An alternate dual-launch architecture is proposed and analyzed against a more established architecture. Instead of a rendezvous in a low-Earth parking orbit, the new architecture performs the rendezvous while the two spacecraft are on an Earth-escape trajectory to the destination NEA. After selecting a target asteroid, 2000 SG344, each architecture will have its best mission compared to the best mission of the other architecture.

Using the new architecture, a mission is created to the chosen NEA, 2000 SG344. A back-up Orion MPCV and a …

The New Bicycle Model: Introducing Software Considerations Early Into The Systems Engineering Design And Integration Process, Nathaniel Dinglasan Angat

Master's Theses

Lockheed Martin Space Systems Company, Sunnyvale, California is in the business of designing and engineering satellites for commercial and government customers. This task is by no means a trivial endeavor but Lockheed MartinSunnyvale has many decades of experience in Systems Engineering. Training in systems engineering is a long process whose training tools must be kept up-to-date and appropriate as new advances in technology evolve along-side with the processes that develop these ever-evolving solutions. For many years new systems engineers have been introduced to the Bicycle Model as a paradigm for designing and developing complex systems that are composed of diverse …

Telescope Assembly Alignment Simulator Performance Optimization, Joshua G. Thompson, Brian Eney, Zaheer Ali, Bob Thompson

STAR Program Research Presentations

The Telescope Assembly Alignment Simulator (TAAS) calibrates scientific instruments (SI’s) that are installed on the Stratospheric Observatory For Infrared Astronomy (SOFIA). An SI’s accuracy is directly dependent on the consistent performance of the TAAS, which has never been fully characterized. After designing various thermal and optical experiments to identify the current unknowns of TAAS, we now have a far better grasp on how the equipment behaves.

Two-Stage, High-Altitude Rocket With Internal Skeleton Design Entered In Advance Category Of 7th Esra Irec, Samuel S. Bowman, Kevin J. Byrne, Allen Capatina, Aliki S. Loper-Leddy, Joshua A. Van Schoyck

Aerospace Engineering

A high-altitude, two-stage rocket was designed, built, and entered in the advanced category of the 7^th Annual Experimental Sounding Rocket Association (ESRA) Intercollegiate Rocketry Engineering Competition (IREC). The rocket, called AJAKS, featured an internal skeleton made of carbon fiber rods, and a combination of plywood, carbon, and aluminum bulkheads. Loads were driven through the internal structure, with an outer skin tube providing an aerodynamic surface. A unique separation device was developed to ensure proper stage separation. The competition required the rocket to carry a 10-lb payload, which was chosen by the team to consist of an IMU and data …

Control System Development For Small Uav Gimbal, Nicholas J. Brake

Master's Theses

The design process of unmanned ISR systems has typically driven in the direction of increasing system mass to increase stabilization performance and imagery quality. However, through the use of new sensor and processor technology high performance stabilization feedback is being made available for control on new small and low mass stabilized platforms that can be placed on small UAVs. This project develops and implements a LOS stabilization controller design, typically seen on larger gimbals, onto a new small stabilized gimbal, the Tigereye, and demonstrates the application on several small UAV aircraft. The Tigereye gimbal is a new 2lb, 2-axis, gimbal …

A Resistance Based Structural Health Monitoring System For Composite Structure Applications, Dennis N. Boettcher

Master's Theses

This research effort explored the possibility of using interwoven conductive and nonconductive fibers in a composite laminate for structural health monitoring (SHM). Traditional SHM systems utilize fiber optics, piezoelectrics, or detect defects by nondestructive test methods by use of sonar graphs or x-rays. However, these approaches are often expensive, time consuming and complicated.

The primary objective of this research was to apply a resistance based method of structural health monitoring to a composite structure to determine structural integrity and presence of defects.

The conductive properties of fiber such as carbon, copper, or constantan - a copper-nickel alloy - can be …

The Effect Of A Low-Velocity Impact On The Flexural Strength And Dynamic Response Of Composite Sandwiches With Damage Arrestment Devices, Kodi A. Rider

Master's Theses

Impact strength is one of the most important structural properties for a designer to consider, but is often the most difficult to quantify or measure. A constant concern in the field of composites is the effect of foreign object impact damage because it is often undetectable by visual inspection. An impact can create interlaminar damage that often results in severe reductions in strength and instability of the structure. The main objective of this study is to determine the effectiveness of a damage arrestment device (DAD) on the mechanical behavior of composite sandwiches, following a low-velocity impact. A 7.56-lb_f crosshead …

An Experimental Investigation Of A Goldschmied Propulsor, Joshua Roepke

Master's Theses

A wind tunnel investigation of an axisymmetric bluff body, known as a Goldschmied propulsor, was completed. This model conceptually combines boundary layer control and boundary layer ingestion into a single complementary system that is intended to use energy to reduce the axial force on the body by eliminating separation and increasing the pressure recovery aft of the body’s maximum thickness. The goal of the current project was to design, fabricate, and fully document the performance of a wind tunnel model incorporating the Goldschmied propulsor concept and complete an examination of its aerodynamic performance. The investigation took place at California Polytechnic …

Hot-Wire Anemometer For The Boundary Layer Data System, William D. Neumeister

Master's Theses

Hot-wire anemometry has been routinely employed for laboratory measurements of turbulence for decades. This thesis presents a hot-wire anemometer suitable for use with the Boundary Layer Data System (BLDS). BLDS provides a unique platform for in- flight measurements because of its small, self-contained, robust design and flexible architecture. Addition of a hot-wire anemometer would provide BLDS with a sensor that could directly measure flow velocity fluctuations caused by turbulence. Hot-wires are commonly operated in constant-temperature mode for high frequency response, but require a carefully tuned bridge. The constant-voltage anemometer (CVA) uses a simple op-amp circuit to improve frequency response over …

Electric Aircraft Propulsion System, Austin J. Doupe

Aerospace Engineering

This report specifies the purpose, assembly, operation, and data collection of a testing apparatus to characterize small electric aircraft propulsion systems designed for commercial use. This apparatus was constructed with the goal of determining overall system characteristics and efficiencies. The apparatus was pushed to a safety limit as deemed by advisor John Dunning and the results of the experiment were an output power of 3.2kW (25% of max rated power) and a system efficiency of 58.6%, both of which occurred at 2200 RPM. Currently the apparatus needs improvement. It should have an upgraded structure to mount to (instead of the …

High-Fidelity Low-Thrust Trajectory Determination Research And Analysis, Tyler Hill

Aerospace Engineering

This document discusses a numerical analysis method for low thrust trajectory propagation known as the proximity quotient or Q-Law. The process uses a Lyapunov feedback control law developed by Petropoulos^[1] to propagate trajectories of spacecraft by minimizing the user defined function at the target orbit. A simplified propagator is created from the core mechanics of this method in MATLAB and tested in several user defined cases to demonstrate its capabilities. Several anomalies arose in test cases where variations in eccentricity, inclination, right ascension of the ascending node, and argument of perigee were specified. Solutions to these anomalies are discussed …

Low Cost Vacuum Chamber Design For Electromagnetic Railgun Operation, Andrew W. Bothwell, David J. Foster

Aerospace Engineering

This report describes the design and fabrication of a low cost vacuum chamber capable of supporting the operation of an electromagnetic railgun. This would be used to simulate the impact of high velocity impacts in space. The vacuum chamber was constructed out of 10in diameter 10ft PVC pipe with a Wye fitting for viewing impacts during testing. The chamber was designed to accommodate a 6.5in X 6.5in X 60in railgun. The vacuum chamber feedthroughs were designed to be able to carry 1-2Mamps at 8kV to the railgun. The vacuum chamber is capable of reaching 50 Torr and remaining under 100 …

Interstellar Mission To Gliese 581, Brock Schmalzel, Brian Tsoi

Aerospace Engineering

This report details a conceptual design for a one-way, interstellar mission, based upon assumed technological advances over the next few hundred years. It addresses the unique challenges associated with an interstellar mission, looking at both developed and theoretical technologies. This report looks specifically at propulsion systems required to reach an exoplanet. In addition, the power, communication, and orbital trajectories are analyzed to see the differences and technological advancements necessary for future missions and the proposed interstellar mission. The destination for the interstellar mission in Gliese 581, a star system located 20.3 light years away and has 5 known planets and …

Accelerating Lambert's Problem On The Gpu In Matlab, Nathan Parrish

Aerospace Engineering

The challenges and benefits of using the GPU to compute solutions to Lambert’s Problem are discussed. Three algorithms (Universal Variables, Gooding’s algorithm, and Izzo’s algorithm) were adapted for GPU computation directly within MATLAB. The robustness of each algorithm was considered, along with the speed at which it could be computed on each of three computers. All algorithms used were found to be completely robust. Computation time was measured for computation within a for-loop, a parfor-loop, and a call to the MATLAB command ‘arrayfun’ with gpuArray-type inputs. Then, a Universal Variables Lambert’s solver was written in CUDA and compiled for use …

Test And Verification Of Vortex Shedding For A 3d Bluff Body, Paul D. Innes, Charles E. Carlson

Aerospace Engineering

Testing of a 3D bluff body with and without end plate tabs was performed in the California Polytechnic State University 3x4 ft low speed wind tunnel. The C_P values were obtained for the test case with no end plate tabs for speeds of 10, 15, 20, and 30 m/s. It was observed that stronger vortex shedding ocured at the higher speed test cases. The model was shimmed to be at approximately 5° angle of attack in order to obtain symmetrical negative C_P spikes for the top and bottom of the model without tabs. Trends were observed and compared …

Instrument Panel Design, Martin Bialy, Amber Carney, Michael Roche

Aerospace Engineering

This project focused on the design and implementation of an Electronic Flight Instrument System for a home built experimental aircraft known as a CH-701. Older aircraft use manual gauges and dials based on varying internal instruments such as gyro’s and the like but many of these traditional instruments to a singular GUI displaying multiple instruments data at one time. These devices are aimed at helping the pilot stay more alert and aware when flying between automatic warnings when in dangerous flying conditions / configurations as well as simplifying the instrument panel to only display what is absolutely necessary. These programs …

Global Launch Vehicle Selector, Keisuke Suzuki

Aerospace Engineering

No abstract provided.

The Numerical Open-Source Many-Body Simulator (Noms), Jason Lloyd Daniel, Javen Kyle Foster-O'Neal

Aerospace Engineering

This paper outlines the setup and creation of an object-oriented N-body simulator as part of a continued project to explore physical phenomenon and human-computer natural interaction technologies. The tools and processes required to build an N-body simulator are also included. Several integrators were evaluated based on their ability to maintain system energy The 2nd order integrator Verlet and 3rd order integrator Hermite algorithms had the greatest accuracy to model large-scale N-body dynamics for their given computation time. Other algorithms required significantly shorter time steps to achieve similar short-term accuracy. At present, NOMS can reasonably simulate 10,000 particles at less than …

Comprehensive Matlab Gui For Determining Barycentric Orbital Trajectories, Steve Katzman

Aerospace Engineering

When a 3-body gravitational system is modeled using a rotating coordinate frame, interesting applications become apparent. This frame, otherwise known as a barycentric coordinate system, rotates about the system’s center of mass. Five unique points known as Lagrange points rotate with the system and have numerous applications for spacecraft operations. The goal of the Matlab GUI was to allow easy manipulation of trajectories in a barycentric coordinate system to achieve one of two end goals: a free-return trajectory or a Lagrange point rendezvous. Through graphical user input and an iterative solver, the GUI is capable of calculating and optimizing both …