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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 1,423 records · Page 79

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NASA NTRS1987

A computer program for performance prediction of tripropellant rocket engines with tangential slot injection

For the development of a Heavy Lift Launch Vehicle (HLLV) several engines with different operating cycles and using LOX/Hydrocarbon propellants are presently being examined. Some concepts utilize hydrogen for thrust chamber wall cooling followed by a gas generator turbine drive cycle with subsequent dumping of H2/O2 combustion products into the nozzle downstream of the throat. In the Space Transportation Booster Engine (STBE) selection process the specific impulse will be one of the optimization criteria; however, the current performance prediction programs do not have the capability to include a third propellant in this process, nor to account for the effect of dumping the gas-generator product tangentially inside the nozzle. The purpose is to describe a computer program for accurately predicting the performance of such an engine. The code consists of two modules; one for the inviscid performance, and the other for the viscous loss. For the first module, the two-dimensional kinetics program (TDK) was modified to account for tripropellant chemistry, and for the effect of tangential slot injection. For the viscous loss, the Mass Addition Boundary Layer program (MABL) was modified to include the effects of the boundary layer-shear layer interaction, and tripropellant chemistry. Calculations were made for a real engine and compared with available data.

Dang, Anthony↗

NASA NTRS1987

Communication training for aircrews: A review of theoretical and pragmatic aspects of training program design

This study is the final report of a project studying methods of communications training applicable to both civilian and military aviation personnel, including multiperson teams or single pilot fixed wing or rotary wing aircraft. A review is provided of a number of theories proposed as relevant for producing training materials for improved communications. Criteria are given for evaluating the applicability of training programs to the aviation environment, and these criteria are applied to United Airlines' Resources Management Training, as well as to a number of commercially available general purpose training programs. The report considers in detail assertiveness training and grid management training, examining their theoretical background and attempts made to validate their effectiveness. It was found that there are substantive difficulties in assessing the effectiveness of both training programs, as well as problems with the theories underlying them. However, because the aviation environment offers unique advantages for studying the effectiveness of communications training, recommendations are made on the design of appropriate training programs and on procedures that might be used to validate them.

Linde, Charlotte↗

NASA NTRS1987

Traditional versus rule-based programming techniques - Application to the control of optional flight information

A traditional programming technique for controlling the display of optional flight information in a civil transport cockpit is compared to a rule-based technique for the same function. This application required complex decision logic and a frequently modified rule base. The techniques are evaluated for execution efficiency and implementation ease; the criterion used to calculate the execution efficiency is the total number of steps required to isolate hypotheses that were true and the criteria used to evaluate the implementability are ease of modification and verification and explanation capability. It is observed that the traditional program is more efficient than the rule-based program; however, the rule-based programming technique is more applicable for improving programmer productivity.

Ricks, Wendell R.↗

NASA NTRS1987

An overview of the Office of Space Flight satellite servicing program plan

A comprehensive program for the development of satellite servicing tools and techniques is being currently carried out by the Office of Space Flight. The program is based on a satellite servicing infrastructure formulated by analyzing satellite servicing requirements; the program is Shuttle-based and compatible with the Orbital Maneuvering Vehicle and Space Station. The content of the satellite servicing program is reviewed with reference to the tools, techniques, and procedures being developed for refueling (or consumables resupply), repairing, and retrieving.

Levin, George M.↗

NASA NTRS1987

Results of NASA's Energy Efficient Engine Program

The major activity undertaken in the NASA Energy Efficient Engine Program has been completed. This paper reports on the progress made toward achieving the program goal of developing advanced technology to significantly reduce fuel consumption and operating costs of future subsonic transport-type propulsion systems. An additional goal was that the advanced concepts be compatible with future environmental regulations. Along with the results obtained, a brief overview of the design details of both the General Electric and Pratt and Whitney energy efficient engines and the overall program scope are presented. Overall, this program has been highly successful; the technology developed during its course is, and will continue to be, effectively employed in both current and future advance transport aircraft engine designs.

Ciepluch, Carl C.↗

NASA NTRS1987

Technology demonstrator program for Space Station Environmental Control Life Support System

The main objectives and requirements of the NASA/Marshall Space Flight Center Technology Demonstration Program are discussed. The program consists of a comparative test and a 90-day manned system test to evaluate an Environmental Control and Life Support System (ECLSS). In the comparative test phase, 14 types of subsystems which perform oxygen and water reclamation functions are to be examined in terms of performance maintenance/service requirements, reliability, and safety. The manned chamber testing phase involves a four person crew using a partial ECLSS for 90 days. The schedule for the program and the program hardware requirements are described.

Adams, Alan M.↗

NASA NTRS1989

Transferring Lens Prescriptions Between Lens-Design Programs

Optical Lens Prescription Data Formatter computer program enables user to transfer complicated lens prescriptions quickly and easily from one major optical-design program to another and back again. One can take advantage of inherent strength of either program. Programs are ACCOS V from Scientific Calculations, Inc., of Fishers, NY, and CODE V from Optical Research Associates of Pasadena, CA. VAX version written in FORTRAN.

Stacy, John E.↗

NASA NTRS1989

System-Reliability Cumulative-Binomial Program

Cumulative-binomial computer program, NEWTONP, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. NEWTONP, CUMBIN (NPO-17555), and CROSSER (NPO-17557), used independently of one another. Program finds probability required to yield given system reliability. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Program written in C.

Scheuer, Ernest M.↗

NASA NTRS1989

AutoCAD-To-NASTRAN Translator Program

Program facilitates creation of finite-element mathematical models from geometric entities. AutoCAD to NASTRAN translator (ACTON) computer program developed to facilitate quick generation of small finite-element mathematical models for use with NASTRAN finite-element modeling program. Reads geometric data of drawing from Data Exchange File (DXF) used in AutoCAD and other PC-based drafting programs. Written in Microsoft Quick-Basic (Version 2.0).

Jones, A.↗

NASA NTRS1988

Development of a verification program for deployable truss advanced technology

Use of large deployable space structures to satisfy the growth demands of space systems is contingent upon reducing the associated risks that pervade many related technical disciplines. The overall objectives of this program was to develop a detailed plan to verify deployable truss advanced technology applicable to future large space structures and to develop a preliminary design of a deployable truss reflector/beam structure for use a a technology demonstration test article. The planning is based on a Shuttle flight experiment program using deployable 5 and 15 meter aperture tetrahedral truss reflections and a 20 m long deployable truss beam structure. The plan addresses validation of analytical methods, the degree to which ground testing adequately simulates flight and in-space testing requirements for large precision antenna designs. Based on an assessment of future NASA and DOD space system requirements, the program was developed to verify four critical technology areas: deployment, shape accuracy and control, pointing and alignment, and articulation and maneuvers. The flight experiment technology verification objectives can be met using two shuttle flights with the total experiment integrated on a single Shuttle Test Experiment Platform (STEP) and a Mission Peculiar Experiment Support Structure (MPESS). First flight of the experiment can be achieved 60 months after go-ahead with a total program duration of 90 months.

Dyer, Jack E.↗

NASA NTRS1988

The Environment for Application Software Integration and Execution (EASIE), version 1.0. Volume 2: Program integration guide

The Environment for Application Software Integration and Execution, EASIE, provides a methodology and a set of software utility programs to ease the task of coordinating engineering design and analysis codes. EASIE was designed to meet the needs of conceptual design engineers that face the task of integrating many stand-alone engineering analysis programs. Using EASIE, programs are integrated through a relational data base management system. In volume 2, the use of a SYSTEM LIBRARY PROCESSOR is used to construct a DATA DICTIONARY describing all relations defined in the data base, and a TEMPLATE LIBRARY. A TEMPLATE is a description of all subsets of relations (including conditional selection criteria and sorting specifications) to be accessed as input or output for a given application. Together, these form the SYSTEM LIBRARY which is used to automatically produce the data base schema, FORTRAN subroutines to retrieve/store data from/to the data base, and instructions to a generic REVIEWER program providing review/modification of data for a given template. Automation of these functions eliminates much of the tedious, error prone work required by the usual approach to data base integration.

Jones, Kennie H.↗

NASA NTRS1988

Automatic programming of simulation models

The objective of automatic programming is to improve the overall environment for describing the program. This improved environment is realized by a reduction in the amount of detail that the programmer needs to know and is exposed to. Furthermore, this improved environment is achieved by a specification language that is more natural to the user's problem domain and to the user's way of thinking and looking at the problem. The goal of this research is to apply the concepts of automatic programming (AP) to modeling discrete event simulation system. Specific emphasis is on the design and development of simulation tools to assist the modeler define or construct a model of the system and to then automatically write the corresponding simulation code in the target simulation language, GPSS/PC. A related goal is to evaluate the feasibility of various languages for constructing automatic programming simulation tools.

Schroer, Bernard J.↗

NASA NTRS1986

Debugging tasked Ada programs

The applications for which Ada was developed require distributed implementations of the language and extensive use of tasking facilities. Debugging and testing technology as it applies to parallel features of languages currently falls short of needs. Thus, the development of embedded systems using Ada pose special challenges to the software engineer. Techniques for distributing Ada programs, support for simulating distributed target machines, testing facilities for tasked programs, and debugging support applicable to simulated and to real targets all need to be addressed. A technique is presented for debugging Ada programs that use tasking and it describes a debugger, called AdaTAD, to support the technique. The debugging technique is presented together with the use interface to AdaTAD. The component of AdaTAD that monitors and controls communication among tasks was designed in Ada and is presented through an example with a simple tasked program.

Fainter, R. G.↗

NASA NTRS1987

Evaluation of aerothermal modeling computer programs

Various computer programs based upon the SIMPLE or SIMPLER algorithm were studied and compared for numerical accuracy, efficiency, and grid dependency. Four two-dimensional and one three-dimensional code originally developed by a number of research groups were considered. In general, the accuracy and computational efficieny of these TEACH type programs were improved by modifying the differencing schemes and their solvers. A brief description of each program is given. Error reduction, spline flux and second upwind differencing programs are covered.

Hsieh, K. C.↗

NASA NTRS1988

NASA Ames Summer High School Apprenticeship Research Program: 1986 research papers

Engineering enrollments are rising in universities; however the graduate engineering shortage continues. Particularly, women and minorities will be underrepresented for many years. As one means of solving this shortage, Federal agencies facing future scientific and technological challenges were asked to participate in the Summer High School Apprenticeship Research Program (SHARP). This program was created to provide an engineering experience for gifted female and minority high school students at an age when they could still make career and education decisions. The SHARP program is designed for high school juniors who are U.S. citizens, are 16 years old, and who have very high promise in math and science through outstanding academic performance in high school. Students who are accepted into this summer program will earn as they learn by working 8 hr days in a 5-day work week. Reports from SHARP students are presented.

Powell, Patricia↗

NASA NTRS1989

The Fault Tree Compiler (FTC): Program and mathematics

The Fault Tree Compiler Program is a new reliability tool used to predict the top-event probability for a fault tree. Five different gate types are allowed in the fault tree: AND, OR, EXCLUSIVE OR, INVERT, AND m OF n gates. The high-level input language is easy to understand and use when describing the system tree. In addition, the use of the hierarchical fault tree capability can simplify the tree description and decrease program execution time. The current solution technique provides an answer precisely (within the limits of double precision floating point arithmetic) within a user specified number of digits accuracy. The user may vary one failure rate or failure probability over a range of values and plot the results for sensitivity analyses. The solution technique is implemented in FORTRAN; the remaining program code is implemented in Pascal. The program is written to run on a Digital Equipment Corporation (DEC) VAX computer with the VMS operation system.

Butler, Ricky W.↗

NASA NTRS1989

An overview of the Douglas Aircraft Company Aeroelastic Design Optimization Program (ADOP)

From a program manager's viewpoint, the history, scope and architecture of a major structural design program at Douglas Aircraft Company called Aeroelastic Design Optimization Program (ADOP) are described. ADOP was originally intended for the rapid, accurate, cost-effective evaluation of relatively small structural models at the advanced design level, resulting in improved proposal competitiveness and avoiding many costly changes later in the design cycle. Before release of the initial version in November 1987, however, the program was expanded to handle very large production-type analyses.

Dodd, Alan J.↗

NASA NTRS1987

An approach to distributed execution of Ada programs

Intelligent control of the Space Station will require the coordinated execution of computer programs across a substantial number of computing elements. It will be important to develop large subsets of these programs in the form of a single program which executes in a distributed fashion across a number of processors. A translation strategy for distributed execution of Ada programs in which library packages and subprograms may be distributed is described. A preliminary version of the translator is operational. Simple data objects (no records or arrays as yet), subprograms, and static tasks may be referenced remotely.

Volz, R. A.↗