Aerospace Engineering Commons^™

Characterizing Strain Accumulation, Residual Stress, And Microstructure Of Additive Manufactured Materials, Hannah K. Woods, Todd A. Book, Catalina Parada, Michael D. Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

Additive Manufacturing (AM) is a rapidly evolving fabrication technology beneficial for its cost-saving potential to produce complex, low-volume shapes. However, AM materials are currently limited to nonstructural applications due to variability in their structural integrity, particularly their fatigue lives. IN718, Ti64, and Al10MgSi specimens manufactured by Direct Metal Laser Sintering (DMLS) were characterized based on variation of post-processing techniques and build direction. To understand the impact of each variable, surface roughness, hardness, residual stresses, microstructure, and strain accumulation in response to Low Cycle Fatigue (LCF) were studied. The use of Electron Backscatter Diffraction (EBSD) provided grain orientation and grain size …

Refinement And Validation Of A Real-Time Airborne System For Remotely Sensing Ocean Surface Using Communication Satellite Signals, Benjamin R. Nold, Han Zhang, James L. Garrison

The Summer Undergraduate Research Fellowship (SURF) Symposium

The ability to remotely sense ocean wave heights and wind speed by measuring the reflected Radio Frequency (RF) signals from the ocean’s surface has been demonstrated in previous research projects. The recording systems for these research projects collected and stored unmodified RF signals and then analyzed the data through post-processing. Several disadvantages to this approach include large requirements for data storage and lengthy post-processing time. To assist in the creation of a suitable platform for an airplane-based application, a new system was designed which features real-time processing of the RF signals. This system captures two RF signals in the 2.4 …

Assessment Of Critical Technologies For Gas Turbine Engines Using Numerical Tools, Vinicius Pessoa Mapelli, Guillermo Paniagua, Jorge Sousa

The Summer Undergraduate Research Fellowship (SURF) Symposium

In 2014 gas turbine engine has reached a market value of 82.5 billion dollars, of which 59.5% are related to aircraft propulsion. The continuous market expansion attracts more and more the interest of researchers and industries towards the development of accurate numerical techniques to model thermodynamically the entire engine. This practice allows a performance and optimization analysis before the actual experimental testing, reducing the time and required investment in the design of a new engine. In this paper, a recently developed open source numerical tool named “Toolbox for the Modeling and Analysis of Thermodynamic Systems” (T-MATS) is used to assess …

Dsmc Simulation Of Microstructure Actuation By Knudsen Thermal Force, Aaron Pikus, Israel Sebastiao, Andrew Strongrich, Alina Alexeenko

The Summer Undergraduate Research Fellowship (SURF) Symposium

In many industrial and research applications there is a need for vacuum sensors with higher accuracy and spatial resolution than what is currently available. Examples of target applications include high-altitude platforms, satellites and in-vacuum manufacturing processes such as freeze-drying of food and pharmaceuticals. In this connection, a novel pressure sensor, named Microelectromechanical In-plane Knudsen Radiometric Actuator (MIKRA), has been developed by at Purdue University. MIKRA is based on Knudsen thermal forces generated by rarefied flow driven by thermal gradients within the microstructure Thus, the goal of this work is to model the rarefied gas flow in the MIKRA sensor under …

High Pressure Combustion And Supersonic Jet Ignition For H2/Air, Michael G. Woodworth, Sayan Biswas, Li Qiao

The Summer Undergraduate Research Fellowship (SURF) Symposium

There are many incentives to increase the fuel efficiency of combustion processes. This paper looks at two available options to achieve this goal. The former aims to develop an experimental method that can analyze combustion at extremely high pressures to improve the understanding of high pressure H2/air combustion. Experimental data has been lacking a suitable combustion diagnostic to visualize high pressure combustion processes, making it difficult to improve the process. Improvement of x-ray diffraction tomography in a windowless combustor makes it possible to see flame propagation at high pressure. The procedure and chamber are still in the design phase, yet …

Hot Surface Ignition, Yerbatyr Tursyn, Vikrant Goyal, Alicia Benhidjeb-Carayon, Richard Simmons, Scott Meyer, Jay P. Gore

The Summer Undergraduate Research Fellowship (SURF) Symposium

Undesirable hot surface ignition of flammable liquids is one of the hazards in ground and air transportation vehicles, which primarily occurs in the engine compartment. In order to evaluate the safety and sustainability of candidate replacement fuels with respect to hot surface ignition, a baseline low lead fuel (Avgas 100 LL) and four experimental unleaded aviation fuels recommended for reciprocating aviation engines were considered. In addition, hot surface ignition properties of the gas turbine fuels Jet-A, JP-8, and JP-5 were measured. A test apparatus capable of providing reproducible data was designed and fabricated to experimentally investigate the hot surface ignition …

Kinetic Modeling Of Roll To Roll Rfcvd Plasma, Kudzo S. Ahegbebu, Siva Sashank Tholeti, Alina A. Alexeenko

The Summer Undergraduate Research Fellowship (SURF) Symposium

Roll-to-roll radio frequency plasma enhanced chemical vapor deposition (R2R RFCVD) is a technique for large-scale synthesis of high quality graphitic nanopetals. Graphitic nanopetals are petal-like graphene structures with remarkable electrical and mechanical properties with major industrial applications such as microsupercapacitors. RFCVD uses a non-equilibrium plasma with high energy electrons to catalyze chemical reactions, induce the creation of free radicals, and promote otherwise high temperature chemistry in a low temperature environment. Understanding how bulk plasma characteristics (particularly, power and number densities) vary with changing reactor parameters is an important step towards optimizing synthesis techniques. In our present work we use the …

Identifying And Correcting Biases In Digital Image Correlation At Multiple Length Scales, Catalina Parada, Alberto W. Da Silva Mello, Michael D. Sangid, Hannah K. Woods, Samuel E. Otto

The Summer Undergraduate Research Fellowship (SURF) Symposium

Accurate strain measurement at grain and sub-grain levels is important to predict and understand crack initiation during fatigue of materials. During cyclic loading, low magnitude strain is accumulated in the material and any distortion in the images can lead to inaccurate strain measurements and false prediction of the material’s behavior. Digital Image Correlation (DIC) is a reliable tool used to measure strain localization by correlating images before, during, and after cyclic loading. DIC tracks the deformation of nano/micro-scale patterns placed on the surface of the specimens to determine strain fields. However, DIC software does not account for biases due to …

Altered Combustion Characteristics Of Aluminum Fuels Through Low-Level Fluoropolymer Inclusions With And Without In Situ Nanoaluminum., Courtney K. Murphy, Brandon Terry, Steven F. Son

The Summer Undergraduate Research Fellowship (SURF) Symposium

Aluminum inclusions have been widely used to increase the specific impulse of solid rocket propellant. However, issues arise with the addition of aluminum in the form of agglomeration, which can cause kinetic and thermal losses (i.e., two-phase flow losses) through the nozzle, which can reduce motor performance by as much as 10%. Reduction of agglomerate size may reduce the effect of two-phase flow losses. Polytetrafluoroethylene (PTFE or Teflon^TM) inclusions into aluminum via mechanical activation (MA, milling) have been shown to produce a smaller coarse agglomerate size due to microexplosion of the composite particles at the propellant surface. Perflouroalkoxy …

Earth Magnetosphere Model Investigations For Coupled Orbit-Attitude Space Debris Perturbations, Eiji Shibata, Carolin Frueh Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

As more objects are placed into orbit, collisions become increasingly more likely, leading to a so-called Kessler Syndrome: collisions between existing debris creates more debris, causing a cascading effect of larger amounts of debris being put into orbit, even in the absence of launches, making future space fairing difficult or impossible. Natural forces influence the orbit and attitude of uncontrolled debris objects. The natural plasma environment can lead to space object charging. The subsequent orbital movement in the geomagnetosphere induces Lorentz forces that act both on the orbit and attitude of the space object. Those forces have not been investigated …

P-Band Satellite Remote Sensing Antenna, Nishtha Sinha, James L. Garrison, Lin Yao-Cheng

The Summer Undergraduate Research Fellowship (SURF) Symposium

Today, there are a huge number of satellites out there in the space orbiting the earth, and there are specific frequency bands allocated for data transmission from these satellites. Signals from these satellites can be accessed at different places on earth, and used for remote sensing. Lower frequency bands are being used in this project, which have not been used earlier for remote sensing. The main idea of this study is to use the properties of two P-band communication satellites to assess their utility for ‘reflectometry’. This remote sensing method is based upon the comparison of the direct and reflected …

Characterization Of Sprays From Dual Impinging Jets On A Splash Plate, Christopher Vodney, Stephen Heister, Brandon Kan, David Stechmann

The Summer Undergraduate Research Fellowship (SURF) Symposium

The use of splash plates and dual impinging liquid jets are common methods for fuel atomization, but the combination of these methods has not been explored. The goal of this experiment is to analyze how splash plate position and orientation affect the spray geometry for this combined method. The spray patterns are observed for a single jet against a splash plate and two orientations of dual impinging jets against a splash plate. For all three cases, the spray patterns are analyzed for various splash plate angles between 30 and 60 degrees relative to the jet centerline. For the dual impinging …

A Brief History Of Space - Sse 120, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "A Brief History of Space" from August 5, 2015.

Book Review: High G Flight - Physiological Effects And Countermeasures, Stefan Kleinke

International Journal of Aviation, Aeronautics, and Aerospace

This review provides insight on the content and a review of the quality of the recent release of High G Flight - Physiological Effects and Countermeasures from Ashgate Publications.

This review does not reflect the views of IJAAA or ERAU. This work was not peer reviewed.

High G Flight - Physiological Effects and Countermeasures

Global Optimized Isothermal And Nonlinear Models Of Earth’S Standard Atmosphere, Nihad E. Daidzic, Ph.D.,

International Journal of Aviation, Aeronautics, and Aerospace

Both, a global isothermal temperature model and a nonlinear quadratic temperature model of the ISA was developed and presented here. Constrained optimization techniques in conjunction with the least-square-root approximations were used to design best-fit isothermal models for ISA pressure and density changes up to 47 geopotential km for NLPAM, and 86 orthometric km for ISOAM respectively. The mass of the dry atmosphere and the relevant fractional-mass scale heights have been computed utilizing the very accurate eight-point Gauss-Legendre numerical quadrature for both ISOAM and NLPAM. Both, the ISOAM and the NLPAM represent viable alternatives to ISA in many practical applications and …

Entropy Minimization Design Approach Of Supersonic Internal Passages, Jorge Sousa, Guillermo Paniagua

School of Aeronautics and Astronautics Faculty Publications

Fluid machinery operating in the supersonic regime unveil avenues towards more compact technology. However, internal supersonic flows are associated with high aerodynamic and thermal penalties, which usually prevent their practical implementation. Indeed, both shock losses and the limited operational range represent particular challenges to aerodynamic designers that should be taken into account at the initial phase of the design process. This paper presents a design methodology for supersonic passages based on direct evaluations of the velocity field using the method of characteristics and computation of entropy generation across shock waves. This meshless function evaluation tool is then coupled to an …

Designing A Remote Aerial System To Image And Analyze The Health Of Grape Crops At Cal Poly San Luis Obispo, Alexander D. Vice, Dylan Benton, Adipratnia Asmady, Andrew Mercier, Andrew Meyer, Eric Belfield, Aaron Drake

STAR Program Research Presentations

In the last decade the prevalence of unmanned aerial vehicles (UAVs) has exploded; however, the presence of UAVs in research situations is still a relatively new and untested field. The autonomous flight lab (AFL) at Cal Poly San Luis Obispo is a new lab site that is dedicated to using UAVs to benefit research for all backgrounds. Before AFL was able to fly missions we first needed to actually receive our vehicles, create a lab space that would provide all of the necessary resources and equipment necessary to fly, and to be granted permission by the Federal Aviation Administration (FAA) …

Development Of Tools Needed For Radiation Analysis Of A Cubesat Deployer Using Oltaris, Marycarmen Gonzalez-Dorbecker

Master's Theses

Currently, the CubeSat spacecraft is predominantly used for missions at Low- Earth Orbit (LEO). There are various limitations to expanding past that range, one of the major ones being the lack of sufficient radiation shielding on the Poly-Picosatellite Orbital Deployer (P-POD). The P-POD attaches to a launch vehicle transporting a primary spacecraft and takes the CubeSats out into their orbit. As the demand for interplanetary exploration grows, there is an equal increase in interest in sending CubeSats further out past their current regime. In a collaboration with NASA’s Jet Propulsion Laboratory (JPL), students from the Cal Poly CubeSat program worked …

Common Calibration Standards For Visible/Infrared Optical Sensors Are Essential To Multi-Sensor Missile Defense Architectures, Joe Tansock, Alan Thurgood, Bruce Guilmain, Garry Schnelzer

Space Dynamics Laboratory Publications

Outline

• What is calibration and why is it important?
• What calibration provides to visible/infrared optical sensors being used for missile defense
• Mapping of missile defense needs to calibration domains
• Calibration planning
• Calibration examples (airborne and spaceborne)
• Summary

Examining How Breakdowns In Pilot Monitoring Of The Aircraft Flight Path, Robert Sumwalt, David Cross, Dennis Lessard

International Journal of Aviation, Aeronautics, and Aerospace

Aircraft accident and incident data reveal that serious safety consequences can arise when flight crewmembers fail to properly monitor the aircraft flight path. This research study reviewed human factors literature to better understand why pilots fail to properly monitor, and analyzed accident and incident data. Recommendations for improving monitoring performance were formulated, which may be useful to air carriers in implementing a new Federal Aviation Administration requirement that calls for specific training in monitoring.