Digital Commons Network^™

Radiation Effects On Space Solar Cells At Various Earth And Jupiter Orbital Altitudes, Naazneen Rana

Discovery Undergraduate Interdisciplinary Research Internship

Solar cells are used as the primary power source for earth-orbiting satellites and as a primary/secondary power source for various missions within the solar system. However, high energy particles from the sun, planetary magnetospheres, and the galaxy can affect the performance and life expectancy of the space solar cell and associated power systems. As the interests for interplanetary travel and the exploration of planets within our solar system increase, the need to understand a device’s performance within a particular planet’s environment is necessary. Therefore, this study will analyze the performance of space solar cells, particularly the SolAero IMM-α, at various …

Congressional Committee Resources On Space Policy During The 115th Congress (2017-2018): Providing Context And Insight Into U.S. Government Space Policy, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Article 1 of the US Constitution assigns the US Congress numerous responsibilities. These include creating new laws, revising existing laws, funding government programs, and conducting oversight of these programs' performance. Oversight of US Government agency space policy programs is executed by various congressional space policy committees, including the House and Senate Science Committees, Armed Services, and Appropriations Committees. These committees conduct many public hearings on space policy which invite witnesses to testify on US space policy programs and feature debate on the strengths and weaknesses of these programs. Documentation produced by these committees is widely available to the public, except …

Turbine Passage Design Methodology To Minimize Entropy Production-A Two-Step Optimization Strategy, Paht Juangphanich, Cis De Maesschalck, Guillermo Paniagua

School of Aeronautics and Astronautics Faculty Publications

Rapid aerodynamic design and optimization is essential for the development of future turbomachinery. The objective of this work is to demonstrate a methodology from 1D mean-line-design to a full 3D aerodynamic optimization of the turbine stage using a parameterization strategy that requires few parameters. The methodology is tested by designing a highly loaded and efficient turbine for the Purdue Experimental Turbine Aerothermal Laboratory. This manuscript describes the entire design process including the 2D/3D parameterization strategy in detail. The objective of the design is to maximize the entropy definition of efficiency while simultaneously maximizing the stage loading. Optimal design trends are …

Numerical Assessment Of The Convective Heat Transfer In Rotating Detonation Combustors Using A Reduced-Order Model, James Braun, Jorge Sousa, Guillermo Paniagua

School of Aeronautics and Astronautics Faculty Publications

The pressure gain across a rotating detonation combustor offers an efficiency rise and potential architecture simplification of compact gas turbine engines. However, the combustor walls of the rotating detonation combustor are periodically swept by both detonation and oblique shock waves at several kilohertz, disrupting the boundary layer, resulting in a rather complex convective heat transfer between the fluid and the solid walls. A computationally fast procedure is presented to calculate this extraordinary convective heat flux along the detonation combustor. First, a numerical model combining a two-dimensional method of characteristics approach with a monodimensional reaction model is used to compute the …

Prediction-Based Adaptive Robust Control For A Class Of Uncertain Time-Delay Systems, Jayaprakash Suraj Nandiganahalli, Cheolhyeon Kwon, Inseok Hwang

School of Aeronautics and Astronautics Faculty Publications

This paper presents an integrated control design approach for a class of dynamical systems that satisfy a certain matching condition subject to known input time-delay, unknown parameters, and time-varying disturbances, simultaneously. A novel nonlinear predictor adaptive robust control (PARC) is proposed to track a desired state trajectory. The controller uses predictor-based model compensation to attenuate the effect of input time-delay, gradient type projection with prediction-based learning mechanisms to reduce the parameter uncertainties, and prediction-based nonlinear robust feedback to attenuate the effect of model approximation errors and disturbances, simultaneously. The controller guarantees a prescribed transient performance (with global exponential convergence) and …

Multi-Stage Nozzle-Shape Optimization For Pulsed Hydrogen-Air Detonation Combustor, Francesco Ornano, James Braun, Bayindir H. Saracoglu, Guillermo Paniagua

School of Aeronautics and Astronautics Faculty Publications

hermal engines based on pressure gain combustion offer new opportunities to generate thrust with enhanced efficiency and relatively simple machinery. The sudden expansion of detonation products from a single-opening tube yields thrust, although this is suboptimal. In this article, we present the complete design optimization strategy for nozzles exposed to detonation pulses, combining unsteady Reynolds-averaged Navier-Stokes solvers with the accurate modeling of the combustion process. The parameterized shape of the nozzle is optimized using a differential evolution algorithm to maxi­ mize the force at the nozzle exhaust. The design of experiments begins with a first optimization considering steady-flow conditions, subsequently …

The Impact Of Crystal Morphology On The Thermal Responses Of Ultrasonically-Excited Energetic Materials, J. K. Miller, J. O. Mares, I. E. Gunduz, Steven F. Son, Jeff Rhoads

Purdue Energetics Research Center Articles

The ability to detect explosive materials may be significantly enhanced with local increases in vapor pressure caused by an elevation of the materials'temperature. Recently, ultrasonic excitation has been shown to generate heat within plastic-bonded energetic materials. To investigate the impact of crystal morphology on this heating, samples of elastic binder are implanted with single ammonium perchlorate crystals of two distinct shape groups. Contact piezoelectric transducers are then used to excite the samples at ultrasonicfrequencies. The thermal responses of the crystals are recorded using infrared thermography, and the rate of heating is estimated. Surface temperature increases up to 15 °C …

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 …

Simulations Of Nanoscale Ni/Al Multilayer Foils With Intermediate Ni2al3 Growth, I. E. Gunduz, S. Onel, C. C. Doumanidis, C. Rebholz, Steven F. Son

Purdue Energetics Research Center Articles

Nanoscale multilayers of binary metallic systems, such as nickel/aluminum, exhibit self-propagating exothermic reactions due to the high formation enthalpy of the intermetallic compounds. Most of the previous modelingapproaches on the reactions of this system rely on the use of mass diffusionwith a phenomenological derived diffusion coefficient representing single-phase (NiAl) growth, coupled with heat transport. We show that the reaction kinetics, temperatures, and thermal front width can be reproduced more satisfactorily with the sequential growth of Ni2Al3 followed by NiAl, utilizing independently obtained interdiffusivities. The computational domain was meshed with a dynamically generated bi-modal grid consisting of fine and coarse zones …

Waste And Duplication In Nasa Programs: The Need To Enhance U.S. Space Program Efficiency, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

The U.S. Government faces acute budgetary deficits and national debt problems in the Obama Administration. These problems have been brought about by decades of unsustainable government spending affecting all agencies including the National Aeronautics and Space Administration. (NASA). An outgrowth of this fiscal profligacy is the presence of wasteful and duplicative programs within NASA that prevent this agency from achieving its space science and human spaceflight objectives. These problems occur due to mismanagement of these programs from NASA and the creation of these programs by the U.S. Congress and congressional committees. This occurs because congressional appropriators tend to be more …

Cognitive Challenges To Resilience Dynamics In Managing Large- Scale Event Response, Barrett S. Caldwell

School of Industrial Engineering Faculty Publications

In early 2014, a number of large-scale adverse weather events in the United States (and elsewhere) have renewed discussions of event response and resilience. Unlike events caused by human error or malicious intent, adverse natural events can be seen as uncontrolled and unpreventable; the measure of response success is the mitigation of adverse and disastrous effects. However, significant cognitive limitations interfere with human decision makers’ ability to effectively estimate likelihood, magnitude, and effective response of large-scale events in the face of multiple forms of uncertainty and system dependencies. Some authors highlight stability and maintenance of original design capability as …

More Effective Human Spaceflight Programs And Their International Security Implications, Bert Chapman, Sarag J. Saikia

Libraries Faculty and Staff Scholarship and Research

NASA can more effectively perform its missions by transferring its aeronautic responsibilities to the Federal Aviation Administration and be renamed the National Space Agency. The U.S. must also recognize that space is an emerging arena of international competition and conflict and militarily protect its space assets from China which seeks to use space to restrict the U.S.' ability to defend its strategic interests in regions such as the Western Pacific.

Comparison Of Best Economy And Best Power Mixture Settings In The Purdue University Training Fleet, Charles G. Chrisman

Purdue Polytechnic Directed Projects

Purdue University operates a fleet of Cirrus SR20s as training aircraft. Standard operating procedures for the cruise portion of cross country training flights call for 65% power with a best power mixture, also called rich of peak, as opposed to a best economy setting, also called lean of peak. Previous work demonstrated that fuel consumption rates, cylinder head temperatures, and true airspeeds are lower when best economy is employed compared to best power for the same power output. This study confirmed that best economy is associated with a lower fuel consumption rate and lower cylinder head temperatures but was unable …

Comparison Of Turbine Engine Test Cell Airborne Nanoparticle Count Versus Ambient Background Particle Count, Ryne Larowe

Purdue Polytechnic Directed Projects

With the establishment of the National Test Facility for Aerospace Fuels and Propulsion at Purdue University in October of 2009, new equipment has been acquired to measure and classify exhaust emissions. This facility utilizes the Honeywell F109 turbofan and Pratt & Whitney PT-6 turboprop engine test cells to analyze the emissions and engine operation of new alternative aviation fuels. This observational study investigates what, if any difference there is in the amount of ambient residual Particulate Matter (PM) in the turbofan engine test cell when compared to ambient particle count associated with the Purdue University Airport (KLAF) property. The project …

Electric Motor & Power Source Selection For Small Aircraft Propulsion, Jeremy Fehrenbacher, David L. Stanley, Mary E. Johnson Dr., Jeffrey Honchell

Purdue Polytechnic Directed Projects

The research conducted in this project is on electrical propulsion in aviation. A Cessna 172K aircraft with a Lycoming O-320-E2D piston engine serves as a baseline measurement. Investigation of the components required for electrical flight is performed, and components are selected based on market availability and operational performance criteria.

This research focuses on electrical propulsion in the aviation industry, and is tailored to aircraft within the General Aviation sector leading to the following research question: Can current electric motor and battery technologies conceptually support flight operations for a Cessna 172K in terms of aircraft performance criteria?

The results explore the …

Crop Production For Advanced Life Support Systems, R M. Wheeler, J C. Sager

Technical Reports

The use of plants for bioregenerative life support for space missions was first studied by the US Air Force in the 1950s and 1960s. Extensive testing was also conducted from the 1960s through the 1980s by Russian researchers located at the Institute of Biophysics in Krasnoyarsk, Siberia, and the Institute for Biomedical Problems in Moscow. NASA initiated bioregenerative research in the 1960s (e.g., Hydrogenomonas) but this research did not include testing with plants until about 1980, with the start of the Controlled Ecological Life Support System (CELSS) Program. The NASA CELSS research was carried out at universities, private corporations, and …

Analysis And Modeling Of Information Flow And Distributed Expertise In Space-Related Operations, Barrett S. Caldwell

School of Industrial Engineering Faculty Publications

Evolving space operations requirements and mission planning for long-duration expeditions require detailed examinationsand evaluations of information flow dynamics, knowledge-sharing processes, and information technology use in distributedexpert networks. This paper describes the work conducted with flight controllers in the Mission Control Center (MCC) ofNASA’s Johnson Space Center. This MCC work describes the behavior of experts in a distributed supervisory coordinationframework, which extends supervisory control/command and control models of human task performance. Findings from thiswork are helping to develop analysis techniques, information architectures, and system simulation capabilities for knowledgesharing in an expert community. These findings are being applied to improve knowledge-sharing processes …