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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 361 records · Page 20

Development of High Strength HEPA Filters for Use in Demanding Air and Gas Streams - 17644

High-efficiency particulate air (HEPA) filters are used in a wide variety of applications, including the removal of radioactive particulate from process off-gas streams and the venting of waste storage containers. Porvair Filtration Group, specializing in the design and manufacture of robust filters in numerous industries, has worked to develop HEPA filter designs for use in such high-demand nuclear process-gas and air streams. Using the requirements of section FK of the American Society of Mechanical Engineers AG-1 Code on Nuclear Air and Gas Treatment (ASME AG-1) as a guide, Porvair Filtration Group has designed filters which can withstand upset conditions to include elevated temperatures, high relative humidity, high particle-loading, and an unconventionally high differential pressure across the filter media; while maintaining excellent removal efficiencies. The process by which Porvair Filtration Group has reached optimized designs was based upon an extended test and development program. Design, manufacture, and testing of flat sheet media samples, geometrically equivalent model filters, and full-scale prototypes was performed at several Porvair Filtration Group facilities located in the United States and the United Kingdom. The methods and results of this development program are outlined in the following paper. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

MSFC's utilization of existing design technology in the Skylab program

In the design of Skylab use was made in a number of cases of technological experience obtained in connection with earlier phases of the space program. In the development of the payload shroud use was made of Saturn V flight data. The shroud thrusting joint system was an adaptation of a system flown on the Titan IIIC. Scientific airlock hardware for Skylab was available from the Apollo Program. The design of the Orbital Workshop was based on the technology base provided by Saturn programs. Details regarding the repair tools used for correcting orbital workshop meteoroid shield/solar array anomalies which occurred during the ascent are discussed along with a commercial concept for coolant resupply, giving attention to aid provided by already existing technological developments.

Eudy, R. G.↗

Artwork Interactive Design System (AIDS) program description

An artwork interactive design system is described which provides the microelectronic circuit designer/engineer a tool to perform circuit design, automatic layout modification, standard cell design, and artwork verification at a graphics computer terminal using a graphics tablet at the designer/computer interface.

Johnson, B. T.↗

An interactive modular design for computerized photometry in spectrochemical analysis

An interactive, top-down structured program design is described which produces a general flexible description of totally automatic photometry of emission spectra in an operating environment in which sample compositions and analysis procedures are low-volume and nonroutine. The use of this type of programming is illustrated by a project to computerize trace elemental determinations including the automated reading of spectrographic plates produced by a 3.4-m Ebert mount spectrograph using a dc-arc in an argon atmosphere.

Bair, V. L.↗

Computer Program for the Design and Off-Design Performance of Turbojet and Turbofan Engine Cycles

The rapid computer program is designed to be run in a stand-alone mode or operated within a larger program. The computation is based on a simplified one-dimensional gas turbine cycle. Each component in the engine is modeled thermo-dynamically. The component efficiencies used in the thermodynamic modeling are scaled for the off-design conditions from input design point values using empirical trends which are included in the computer code. The engine cycle program is capable of producing reasonable engine performance prediction with a minimum of computer execute time. The current computer execute time on the IBM 360/67 for one Mach number, one altitude, and one power setting is about 0.1 seconds. about 0.1 seconds. The principal assumption used in the calculation is that the compressor is operated along a line of maximum adiabatic efficiency on the compressor map. The fluid properties are computed for the combustion mixture, but dissociation is not included. The procedure included in the program is only for the combustion of JP-4, methane, or hydrogen.

Morris, S. J.↗

An Automated FORTRAN documenter

A set of programs designed to help R&D programmers document their FORTRAN programs more effectively were written. The central program reads FORTRAN source code and asks the programmer questions about things it has not heard of before. It inserts the answers to these questions as comments into the FORTRAN code. The comments, as well as extensive cross-reference information, are also written to an unformatted file. Other programs read this file to produce printed information or to act as an interactive document.

Erickson, T.↗

ADS: A FORTRAN program for automated design synthesis, version 1.00

A new general-purpose optimization program for engineering design is described. ADS-1 (Automated Design Synthesis - Version 1) is a FORTRAN program for solution of nonlinear constrained optimization problems. The program is segmented into three levels, being strategy, optimizer, and one-dimensional search. At each level, several options are available so that a total of over 100 possible combinations can be created. Examples of available strategies are sequential unconstrained minimization, the Augmented Lagrange Multiplier method, and Sequential Linear Programming. Available optimizers include variable metric methods and the Method of Feasible Directions as examples and one-dimensional search options include polynomial interpolation and the Golden Section method as examples. Emphasis is placed on ease of use of the program. All information is transferred via a single parameter list. Default values are provided for all internal program parameters such as convergence criteria, and the user is given a simple means to over-ride these, if desired. The program is demonstrated with a simple structural design example.

Vanderplaats, G. N.↗

Propeller aircraft interior noise model utilization study and validation

Utilization and validation of a computer program designed for aircraft interior noise prediction is considered. The program, entitled PAIN (an acronym for Propeller Aircraft Interior Noise), permits (in theory) predictions of sound levels inside propeller driven aircraft arising from sidewall transmission. The objective of the work reported was to determine the practicality of making predictions for various airplanes and the extent of the program's capabilities. The ultimate purpose was to discern the quality of predictions for tonal levels inside an aircraft occurring at the propeller blade passage frequency and its harmonics. The effort involved three tasks: (1) program validation through comparisons of predictions with scale-model test results; (2) development of utilization schemes for large (full scale) fuselages; and (3) validation through comparisons of predictions with measurements taken in flight tests on a turboprop aircraft. Findings should enable future users of the program to efficiently undertake and correctly interpret predictions.

Pope, L. D.↗

Coordinated solar observations obtained during the GRO/Max 1991 target-of-opportunity campaign of June 1991

Max 1991 is a program designed to facilitate coordinated observations of solar activity. The program provides and infrastructure for supporting coordinated observations during observing 'campaigns' through various means of electronic communications combined with the ability to monitor real-time solar conditions at NOAA's Space Environment Laboratory. Prior to the extreme solar activity exhibited by active region 6659 combined with the repointing of the Gamma Ray Observatory (GRO) provided Max 1991 with its first opportunity to call an unscheduled campaign and the world community responded with a surprising degree of observational support. Some of the activity and some of the types of observations that were collected simultaneously with the GRO complement of instruments.

Kiplinger, Alan L.↗

Design for Minimum Casualty Area – The IXPE Case

The Imaging X-Ray Polarimetry Explorer (IXPE) is a new international space observatory in NASA’s Small Explorer program, designed in a collaboration between the Italian Space Agency and NASA’s Marshall Space Flight Center, and built by Ball Aerospace. IXPE has an expected launch in November 2021, to a 600-km altitude equatorial orbit. IXPE is an astrophysics mission using three telescope assemblies to measure the polarization of cosmic X-rays. Each assembly is composed of a mirror module assembly (MMA) with 24 nested nickel-cobalt cylindrical shells and a unique, polarization-sensitive, gas pixel detector (GPD) within the detector unit (DU). As a NASA mission, IXPE must adhere to the orbital debris mitigation requirements specified in NASA Standard 8719.14 [1]; in the present work, we will only discuss reentry human casualty risk. As initially designed, the IXPE observatory exceeded NASA’s casualty risk threshold. IXPE does not include a propulsion system to perform a controlled reentry at the end of mission to mitigate the ground casualty risk. To reduce the risk from the uncontrolled reentry of this observatory, the IXPE design team worked with the NASA Orbital Debris Program Office to reduce the debris casualty area through design-for-demise and containment methods. The flight design of IXPE is now compliant with the ground casualty risk requirement at a casualty probability of 1:13,100 compared to a casualty requirement of better than 1:10,000.

C Ostrom↗

Community Solar for All: Key Findings for State Energy Offices and State LIHEAP Agencies from the Inclusive Shared Solar Initiative

Despite the significant potential for community solar to reduce energy burdens and costs, it has largely remained out of reach for low-income households. While the U.S. community solar market has grown considerably over the last decade, as of December 2022 low to moderate-income (LMI) community solar represented just 2% of the overall market. Effective community solar policies and program decisions can help address this dynamic. State laws, policies, and program rules are critical to the development of community solar programs and projects that are affordable for and cater to the needs of LMI utility customers, who often face disproportionately high energy costs relative to their incomes. This report explores how two sets of state agencies in particular — State and Territory Energy Offices and State Low Income Home Energy Assistance Program (LIHEAP) Agencies —can help to streamline and prioritize the delivery of affordable and accessible shared solar. State Energy Offices are often involved in community solar policy and program design from inception, whether by supporting the enactment of enabling legislation or informing the development of program rules and regulations. State Energy Offices may also be charged with administering or overseeing the implementation of statewide community solar programs and, through the U.S. State Energy Program and other sources of funding, can provide resources and loans that enhance community, developer, and utility confidence and capacity to build, host, and derive value from projects. Relatedly, as implementers of federal LIHEAP block grants, State LIHEAP Agencies have a deep understanding of the needs of lower-income households and can help inform the design and delivery of community solar programs.

14 SOLAR ENERGY↗

AESOP: An interactive computer program for the design of linear quadratic regulators and Kalman filters

AESOP is a computer program for use in designing feedback controls and state estimators for linear multivariable systems. AESOP is meant to be used in an interactive manner. Each design task that the program performs is assigned a "function" number. The user accesses these functions either (1) by inputting a list of desired function numbers or (2) by inputting a single function number. In the latter case the choice of the function will in general depend on the results obtained by the previously executed function. The most important of the AESOP functions are those that design,linear quadratic regulators and Kalman filters. The user interacts with the program when using these design functions by inputting design weighting parameters and by viewing graphic displays of designed system responses. Supporting functions are provided that obtain system transient and frequency responses, transfer functions, and covariance matrices. The program can also compute open-loop system information such as stability (eigenvalues), eigenvectors, controllability, and observability. The program is written in ANSI-66 FORTRAN for use on an IBM 3033 using TSS 370. Descriptions of all subroutines and results of two test cases are included in the appendixes.

Lehtinen, B.↗