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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 955 records · Page 53
All sourcesNASA NTRSDOE OSTI
NASA NTRS2023

Python Based Plume Dynamics Estimation Tool (PyPDET) Rapid Plume Strike Analysis for RPOD Maneuvers in Deep Space Operations

I worked as a NASA Intern during the Summer 2023 term in the DS-00 division under the supervision of my mentor, Dr. Jonathan Pitt. Our goal was to build on our previous work from 2022 to develop a plume strike estimation tool using a prescribed physics methodology and model plume impingement effects while considering the dynamics of a rendezvous, operations, proximity, and docking (RPOD) maneuver. This tool supports previously configured CFD-DSMC calculations by allowing for rapid analysis of initial designs using a low-fidelity source flow model. Engineers can then use the high-fidelity CFD-DSMC tool to consolidate results as they work towards finalizing a design. This year’s project was focused on developing a software application that other engineers would be using in their analysis. Thus, the user’s experience was considered in the development of this application. Proper documentation, testability, and modularity of the codebase was our priority. For example, the project included auto documentation procedures to start building towards a User Manual, while also including dedicated demonstration cases for more explicit communication of functionality. Also, this project included a framework for testing the source code for future developments. Additionally, care was taken to develop the code using an Object-Oriented Programming approach. Thus, allowing for a modular extensibility of functionality in anticipation of future developments. The core work of this project was developing an algorithm that would transform the visiting vehicle and associated thruster data according to the kinematics described in the jet firing history. It would then calculate the estimated plume strikes on two of the target vehicles and write data accordingly into a VTK file. Summer work is to conclude by developing and presenting a PowerPoint slide deck at the intern exit briefing on August 11 th , 2023. Once the model for simple plume strike calculations is developed and tested there are several avenues to explore to continue development of this tool. These are also discussed in this report.

Plume Impingement↗
NASA NTRS1985

Techniques, problems and uses of mega-geomorphological mapping

A plea for a program of global geomorphological mapping based on remote sensing data is presented. It is argued that the program is a necessary step in bringing together the rapidly evolving concepts of plate tectonics with the science of geomorphology. Geomorphologists are urged to bring temporal scales into their subject and to abandon their recent isolation from tectonics and geological history. It is suggested that a start be made with a new geomorphological map of Europe, utilizing the latest space technology.

Embleton, C.↗
NASA NTRS1987

Overview of NASA Lewis Research Center free-piston Stirling engine technology activities applicable to space power systems

A brief overview is presented of the development and technological activities of the free-piston Stirling engine. The engine started as a small scale fractional horsepower engine which demonstrated basic engine operating principles and the advantages of being hermetically sealed, highly efficient, and simple. It eventually developed into the free piston Stirling engine driven heat pump, and then into the SP-100 Space Reactor Power Program from which came the Space Power Demonstrator Engine (SPDE). The SPDE successfully operated for over 300 hr and delivered 20 kW of PV power to an alternator plunger. The SPDE demonstrated that a dynamic power conversion system can, with proper design, be balanced; and the engine performed well with externally pumped hydrostatic gas bearings.

Slaby, Jack G.↗
NASA NTRS1989

Designing the Space Transfer Vehicle (STV)

The most significant challenges facing the Space Transfer Vehicle (STV) program are making space basing affordable and developing an easily evolvable STV. Study efforts try minimizing the high cost of astronauts activities and Space Station modification to enhance affordability. Modularity, design margins, and simple interfaces are being evaluated to develop an evolutionary approach for space basing starting in the 1990's. In this STV study, the concept definition approach is presented, including concept optimization trades as well as concept selection and sensitivity analyses.

Austin, Gene↗
NASA NTRS1992

NASA Johnson Space Center: Total quality partnership

The development of and benefits realized from a joint NASA, support contractor continuous improvement process at the Johnson Space Center (JSC) is traced. The joint effort described is the Safety, Reliability, and Quality Assurance Directorate relationship with its three support contractors which began in early 1990. The Continuous Improvement effort started in early 1990 with an initiative to document and simplify numerous engineering change evaluation processes. This effort quickly grew in scope and intensity to include process improvement teams, improvement methodologies, awareness, and training. By early 1991, the support contractor had teams in place and functioning, program goals established and a cultural change effort underway. In mid-l991 it became apparent that a major redirection was needed to counter a growing sense of frustration and dissatisfaction from teams and managers. Sources of frustration were isolated to insufficient joint participation on teams, and to a poorly defined vision. Over the next year, the effort was transformed to a truly joint process. The presentation covers the steps taken to define vision, values, goals, and priorities and to form a joint Steering Committee and joint process improvement teams. The most recent assessment against the President's award criteria is presented as a summary of progress. Small, but important improvement results have already demonstrated the value of the joint effort.

Harlan, Charlie↗
NASA NTRS2000

MU-SPIN Conference Explorers Program Perspective

The mission of the Explorer Program is to provide frequent flight opportunities for world-class scientific investigations from space within the following space science themes: (1) Astronomical Search for Origins and Planetary Systems; (2) Structure and Evolution of the Universe (3) The Sun-Earth Connection. America's space exploration started with Explorer 1: (1) Launched February 1, 1958; (2) Discovered the Van Allen Radiation Belts; (3) Over 75 Explorer missions have flown.

Barrowman, Jim↗
NASA NTRS2004

Simplifying CEA through Excel, VBA, and Subeq

Many people use compound equilibrium programs for very different reasons, varying from refrigerators to light bulbs to rockets. A commonly used equilibrium program is CEA. CEA can take various inputs such as pressure, temperature, and volume along with numerous reactants and run them through equilibrium equations to obtain valuable output information, including products formed and their relative amounts. A little over a year ago, Bonnie McBride created the program subeq with the goal to simplify the calling of CEA. Subeq was also designed to be called by other programs, including Excel, through the use of Visual Basic for Applications (VBA). The largest advantage of using Excel is that it allows the user to input the information in a colorful and user-friendly environment while allowing VBA to run subeq, which is in the form of a FORTRAN DLL (Dynamic Link Library). Calling subeq in this form makes it much faster than if it were converted to VBA. Since subeq requires such large lists of reactant and product names, all of which can't be passed in as an array, subeq had to be changed to accept very long strings of reactants and products. To pass this string and adjust the transfer of input and output parameters, the subeq DLL had to be changed. One program that does this is Compaq Visual FORTRAN, which allows DLLs to be edited, debugged, and compiled. Compaq Visual FORTRAN uses FORTRAN 90/95, which has additional features to that of FORTRAN 77. My goals this summer include finishing up the excel spreadsheet of subeq, which I started last summer, and putting it on the Internet so that others can use it without having to download my spreadsheet. To finish up the spreadsheet I will need to work on debugging current options and problems. I will also work on making it as robust as possible, so that all errors that may arise will be clearly communicated to the user. New features will be added old ones will be changed as I receive comments from people using the spreadsheet. To implement this onto the Internet, I will need to develop an XML input/output format and learn how to write HTML.

Foster, Ryan↗
NASA NTRS2005

NASA Summer Faculty Fellowship Program 2004, Volumes 1 and 2

The objective of the planned summer research was to develop a procedure to determine the isokinetic functional strength of suited and unsuited participants in order to estimate the coefficient of micro-gravity suit on human strength. To accomplish this objective, the Anthropometry and Biomechanics Facility Multipurpose, Multiaxial Isokinetic dynamometer (MMID) was used. Development of procedure involved selection and testing of seven routines to be tested on MMID. We conducted the related experiments and collected the data for 12 participants. In addition to the above objective, we developed a procedure to assess the fatiguing characteristics of suited and unsuited participants using EMG technique. We collected EMG data on 10 participants while performing a programmed routing on MMID. EMG data along with information on the exerted forces, effector speed, number of repetitions, and duration of each routine were recorded for further analysis. Finally, gathering and tabulation Of data for various human strengths for updating of MSIS (HSIS) strength requirement, which started in summer 2003, also continued.

Hyman, William A.↗
NASA NTRS2005

Evaluation of Suited and Unsuited Human Functional Strength Using Multipurpose, Multiaxial Isokinetic Dynamometer

The objective of the planned summer research was to develop a procedure to determine the isokinetic functional strength of suited and unsuited participants in order to estimate the coefficient of micro-gravity suit on human strength. To accomplish this objective, the Anthropometry and Biomechanics Facility's Multipurpose, Multiaxial Isokinetic dynamometer (MMID) was used. Development of procedure involved selection and testing of seven routines to be tested on MMID. We conducted the related experiments and collected the data for 12 participants. In addition to the above objective, we developed a procedure to assess the fatiguing characteristics of suited and unsuited participants using EMG technique. We collected EMG data on 10 participants while performing a programmed routing on MMID. EMG data along with information on the exerted forces, effector speed, number of repetitions, and duration of each routine were recorded for further analysis. Finally, gathering and tabulation Of data for various human strengths for updating of MSIS (HSIS) strength requirement, which started in summer 2003, also continued.

Aghazadeh, Fred↗
NASA NTRS2005

XMM-Newton observations of CYGNUS X-1

Observations of Cygnus X-1 were first attempted under this program in the spring of 2004, but were complicated by instrumental flaring problems. Successful observations were completed in the fall of 2004, and processed data were delivered to the PI in the winter and spring of 2005. Thus, focused work on this data was only possible starting in 2005. A preliminary reduction and analysis of data from the EPIC CCD cameras and the Reflection Grating Spectrometer has been made. The EPIC spectra reveal the best example of a broadened, relativistic iron emission line yet found in Cygnus X-1. The Oxygen K-shell region has been shown to be a very complex wavelength range in numerous spectra of accreting sources, but the RGS spectra reveal this region in great detail and will be important in understanding the wind from the 0-type donor star that is focused onto the black hole in Cygnus X-1.

Mushotzky, Richard F.↗
NASA NTRSDate not supplied

Assessment of the Fluid Network for the Effusion Holes in a RQL (Rich-burn, Quick-quench, Lean-burn) Gas Turbine Combustor

The transient processes involving lean blowout (LBO) in a RQL combustor such as the single cup combustor in the National Jet Fuels Combustion Program (NJFCP) referee rig are simulated with the reduced mechanisms based on Hybrid Chemistry for three different fuels, A2, C1 and C4. Experiments conducted in the NJFCP referee rig established a stable flame at a global equivalence ratio of 0.096 (the near LBO condition) as the starting condition for LBO tests performed with all A and C fuels. Simulations of the approach to LBO verify that a stable flame is established at the near-LBO condition for each fuel before reducing fuel flow rate (and thus equivalence ratio) in a stepwise manner. Main conclusions are: (1) For A2 fuel the equivalence ratio for LBO is 0.081 (2) For C1 fuel the equivalence ratio for LBO is 0.087 or 0.085depended on different step-down transition paths. (3) For C4 fuel the equivalence ratio for LBO is 0.087 or 0.084 depended on types of mesh or boundary conditions. (4) The fuel relative difference from LES on LBO for C1 fuel relative to A2 fuel is 7.40% or 4.94% versus 7.83% from the experimental data. (5) The fuel relative difference from LES on LBO for C4 fuel relative to A2 is 6.17% or 7.69% versus 5.21% from the experimental data

Lean blow out↗
NASA NTRSDate not supplied

Assessment of the Fluid Network for the Effusion Holes in a RQL (Rich-burn, Quick-quench, Lean-burn) Gas Turbine Combustor

The transient processes involving lean blowout (LBO) in a RQL combustor such as the single cup combustor in the National Jet Fuels Combustion Program (NJFCP) referee rig are simulated with the reduced mechanisms based on Hybrid Chemistry for three different fuels, A2, C1 and C4. Experiments conducted in the NJFCP referee rig established a stable flame at a global equivalence ratio of 0.096 (the near LBO condition) as the starting condition for LBO tests performed with all A and C fuels. Simulations of the approach to LBO verify that a stable flame is established at the near-LBO condition for each fuel before reducing fuel flow rate (and thus equivalence ratio) in a stepwise manner. Main conclusions are: (1) For A2 fuel the equivalence ratio for LBO is 0.081 (2) For C1 fuel the equivalence ratio for LBO is 0.087 or 0.085 depended on different step-down transition paths. (3) For C4 fuel the equivalence ratio for LBO is 0.087 or 0.084 depended on types of mesh or boundary conditions. (4) The fuel relative difference from LES on LBO for C1 fuel relative to A2 fuel is 7.40% or 4.94% versus 7.83% from the experimental data. (5) The fuel relative difference from LES on LBO for C4 fuel relative to A2 is 6.17% or 7.69% versus 5.21% from the experimental data.

Lean Blow out↗
NASA NTRSDate not supplied

NASA’s Orbital Debris Optical Program: ES-MCAT Nearing Full Operational Capability (FOC)

The NASA JAO/ES-MCAT (Eugene Stansbery Meter Class Autonomous Telescope) Facility is nearing Full Operational Capability, or FOC. ES-MCAT is now fully capable of autonomously running all observations, including: (a) monitoring weather and closing when conditions are not safe, as well as halting observations when conditions are not suitable (e.g. too cloudy) for operations, (b) start-up/shut-down nightly tasking, (c) collecting calibration data and survey or TLE-tracked data, and (d) processing all collected data, including on-chip photometry and astrometry calibrations using the GAIA star catalogue. The processed data are then further analyzed at NASA Johnson Space Center to correlate detections with known objects in the Space Surveillance Network (SSN) catalogue. MCAT can collect data of specific objects with known orbits or can search for objects with orbits similar to those of spacecraft or rocket bodies that have recently broken up. However, the primary goal for ES-MCAT is to survey the geosynchronous (GEO) belt to provide a statistical sample of the GEO debris environment for both engineering models for spacecraft designers and long-term environment evolutionary purposes. The approach for sweeping the sky to statistically survey GEO has been investigated and updated from past surveys taken by NASA and will be reported, herein referred to as the Candy Cane method. ES-MCAT’s optical performance and the limiting magnitude for the full optical system will be discussed. An analysis used to determine which filter to use for GEO surveys (SDSS r′) includes combining the reflectivity of the primary and secondary mirrors, transmission of the field corrector and CCD window, and the quantum efficiency of the CCD detector, resulting in throughput of the full optical path. This throughput is then combined with the expected typical transparency of the atmosphere at ES-MCAT’s altitude/location for the Sloan Digital Sky Survey (SDSS) g′r′i′z′ and Johnson/Kron-Cousins BVRI filters to yield expected relative throughput.

S. M. Lederer↗
NASA NTRS1972

Guidance system operations plan for manned CM earth orbital missions using program Skylark 1. Section 2: Data links

A computer program to define the digital uplink and downlink for use in manned command module orbital missions is presented. The subjects discussed are: (1) digital uplink to command module, (2) CMC digital downlink, (3) downlist formats, (4) description of telemetered qualities, (5) flagbits, and (6) effects of Fresh Start (V36) and Hardware Restart on flagword and channel bits.

Hamilton, M. H.↗
NASA NTRS1975

Discrete time modelization of human pilot behavior

This modelization starts from the following hypotheses: pilot's behavior is a time discrete process, he can perform only one task at a time and his operating mode depends on the considered flight subphase. Pilot's behavior was observed using an electro oculometer and a simulator cockpit. A FORTRAN program has been elaborated using two strategies. The first one is a Markovian process in which the successive instrument readings are governed by a matrix of conditional probabilities. In the second one, strategy is an heuristic process and the concepts of mental load and performance are described. The results of the two aspects have been compared with simulation data.

Cavalli, D.↗
NASA NTRS1985

Productivity improvement in engineering at Rocketdyne

The Rocketdyne Division of Rockwell International has embarked on a productivity improvement program in engineering. This effort included participation in the White Collar Productivity Improvement (WCPI) project sponsored by the American Productivity Center. A number of things have been learned through this project. It seems that any productivity improvement project should be employee driven. The Rocketdyne project was essentially started as a result of a grassroots effort to remove some particular hindrances, and employee enthusiasm was a prime factor in the continuing progress of the effort. A significant result was that awareness of problems at all levels increased. Many issues surfaced in the diagnostic phase, and were then noted and discussed. This process added legitimacy to issues that had previously been merely unspoken concerns. The initial feelings of many members of the pilot group was that significant changes would occur relatively quickly. It is now recognized that this will have to be an ongoing, long-term effort.

Nordlund, R. M.↗
NASA NTRS1988

A method for designing robust multivariable feedback systems

A new methodology is developed for the synthesis of linear, time-invariant (LTI) controllers for multivariable LTI systems. The aim is to achieve stability and performance robustness of the feedback system in the presence of multiple unstructured uncertainty blocks; i.e., to satisfy a frequency-domain inequality in terms of the structured singular value. The design technique is referred to as the Causality Recovery Methodology (CRM). Starting with an initial (nominally) stabilizing compensator, the CRM produces a closed-loop system whose performance-robustness is at least as good as, and hopefully superior to, that of the original design. The robustness improvement is obtained by solving an infinite-dimensional, convex optimization program. A finite-dimensional implementation of the CRM was developed, and it was applied to a multivariate design example.

Milich, David Albert↗
NASA NTRS1988

A method for designing robust multivariable feedback systems

A new methodology is developed for the synthesis of linear, time-invariant (LTI) controllers for multivariable LTI systems. The aim is to achieve stability and performance robustness of the feedback system in the presence of multiple unstructured uncertainty blocks; i.e., to satisfy a frequency-domain inequality in terms of the structured singular value. The design technique is referred to as the causality recovery methodology (CRM). Starting with an initial (nominally) stabilizing compensator, the CRM produces a closed-loop system whose performance-robustness is at least as good as, and hopefully superior to, that of the original design. The robustness improvement is obtained by solving an infinite-dimensional, convex optimization program. A finite-dimensional implementation of the CRM was developed, and it was applied to a multivariate design example.

Milich, David A.↗