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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 703 records · Page 39
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Approximate method for calculating transonic flow about lifting wing-body configurations: Computer program and user's manual

A user's manual is presented for a computer program which calculates inviscid flow about lifting configurations in the free-stream Mach-number range from zero to low supersonic. Angles of attack of the order of the configuration thickness-length ratio and less can be calculated. An approximate formulation was used which accounts for shock waves, leading-edge separation and wind-tunnel wall effects.

Barnwell, R. W.↗
NASA NTRS1977

Simplified computer program for the analysis of phase change in liquid face seals

A simplified computer program is presented which allows for the prediction of boiling (phase change) in liquid face seals. The program determines if and when boiling occurs and then calculates the location of the boiling interface, pressure and temperature profiles, and load. The main assumption which allows for a simplified analysis is the assumption of an isothermal gas phase.

Birchak, M.↗
NASA NTRS1978

A computer program for the transient thermal analysis of an impingement cooled turbine blade

A computer program to calculate transient and steady state temperatures, pressures, and coolant flows in a cooled turbine blade or vane with an impingement insert is described. Input to the program includes a description of the blade geometry, coolant supply conditions, outside thermal boundary conditions and wheel speed. Coolant-side heat transfer coefficients are calculated internally in the program, with the user specifying the mode of heat transfer at each internal flow station. Program output includes the temperature at each node, the coolant pressures and flow rates, and the inside heat transfer coefficients. A sample problem is discussed.

Gaugler, R. E.↗
NASA NTRS1978

A computer program for the transient thermal analysis of an impingement cooled turbine blade

A computer program to calculate transient and steady state temperatures, pressures, and coolant flows in a cooled turbine blade or vane with an impingement insert is described. Input to the program includes a description of the blade geometry, coolant supply conditions, outside thermal boundary conditions and wheel speed. Coolant-side heat transfer coefficients are calculated internally in the program, with the user specifying the mode of heat transfer at each internal flow station. Program output includes the temperature at each node, the coolant pressures and flow rates, and the inside heat transfer coefficients. A sample problem is discussed.

Gaugler, R. E.↗
NASA NTRS1978

The PR2D (Place, Route in 2-Dimensions) automatic layout computer program handbook

Place, Route in 2-Dimensions is a standard cell automatic layout computer program for generating large scale integrated/metal oxide semiconductor arrays. The program was utilized successfully for a number of years in both government and private sectors but until now was undocumented. The compilation, loading, and execution of the program on a Sigma V CP-V operating system is described.

Edge, T. M.↗
NASA NTRS1980

Computer program documentation for the dynamic analysis of a noncontacting mechanical face seal

A computer program is presented which achieves a numerical solution for the equations of motion of a noncontacting mechanical face seal. The flexibly-mounted primary seal ring motion is expressed by a set of second order differential equations for three degrees of freedom. These equations are reduced to a set of first order equations and the GEAR software package is used to solve the set of first order equations. Program input includes seal design parameters and seal operating conditions. Output from the program includes velocities and displacements of the seal ring about the axis of an inertial reference system. One example problem is described.

Auer, B. M.↗
NASA NTRS1986

Computer Program for Space-Shuttle Testing

Demand on Space Shuttle general-purpose computers reduced. Simulations Testbed and Scenario Pre-processor (STB&SPP) system reduces need for use of GPC's in hardware and software development and testing. System consists of computer program, SPP, and set of utility subroutines, STB, which incorporates Interface Simulator (ISIM). STB&SPP system written in FORTRAN V and Assembler.

Hyman, M. D.↗
NASA NTRS1985

VORSTAB: A computer program for calculating lateral-directional stability derivatives with vortex flow effect

A computer program based on the Quasi-Vortex-Lattice Method of Lan is presented for calculating longitudinal and lateral-directional aerodynamic characteristics of nonplanar wing-body combination. The method is based on the assumption of inviscid subsonic flow. Both attached and vortex-separated flows are treated. For the vortex-separated flow, the calculation is based on the method of suction analogy. The effect of vortex breakdown is accounted for by an empirical method. A summary of the theoretical method, program capabilities, input format, output variables and program job control set-up are described. Three test cases are presented as guides for potential users of the code.

Lan, C. Edward↗
NASA NTRS1988

Permanent-File-Validation Utility Computer Program

Errors in files detected and corrected during operation. Permanent File Validation (PFVAL) utility computer program provides CDC CYBER NOS sites with mechanism to verify integrity of permanent file base. Locates and identifies permanent file errors in Mass Storage Table (MST) and Track Reservation Table (TRT), in permanent file catalog entries (PFC's) in permit sectors, and in disk sector linkage. All detected errors written to listing file and system and job day files. Program operates by reading system tables , catalog track, permit sectors, and disk linkage bytes to vaidate expected and actual file linkages. Used extensively to identify and locate errors in permanent files and enable online correction, reducing computer-system downtime.

Derry, Stephen D.↗
NASA NTRS1977

Computer program for analysis of coupled-cavity traveling wave tubes

A flexible, accurate, large signal computer program was developed for the design of coupled cavity traveling wave tubes. The program is written in FORTRAN IV for an IBM 360/67 time sharing system. The beam is described by a disk model and the slow wave structure by a sequence of cavities, or cells. The computational approach is arranged so that each cavity may have geometrical or electrical parameters different from those of its neighbors. This allows the program user to simulate a tube of almost arbitrary complexity. Input and output couplers, severs, complicated velocity tapers, and other features peculiar to one or a few cavities may be modeled by a correct choice of input data. The beam-wave interaction is handled by an approach in which the radio frequency fields are expanded in solutions to the transverse magnetic wave equation. All significant space harmonics are retained. The program was used to perform a design study of the traveling-wave tube developed for the Communications Technology Satellite. Good agreement was obtained between the predictions of the program and the measured performance of the flight tube.

Connolly, D. J.↗
NASA NTRS1983

Integrating computer programs for engineering analysis and design

The design of a third-generation system for integrating computer programs for engineering and design has been developed for the Aerospace Vehicle Interactive Design (AVID) system. This system consists of an engineering data management system, program interface software, a user interface, and a geometry system. A relational information system (ARIS) was developed specifically for the computer-aided engineering system. It is used for a repository of design data that are communicated between analysis programs, for a dictionary that describes these design data, for a directory that describes the analysis programs, and for other system functions. A method is described for interfacing independent analysis programs into a loosely-coupled design system. This method emphasizes an interactive extension of analysis techniques and manipulation of design data. Also, integrity mechanisms exist to maintain database correctness for multidisciplinary design tasks by an individual or a team of specialists. Finally, a prototype user interface program has been developed to aid in system utilization.

Wilhite, A. W.↗
NASA NTRS1974

A users manual for a computer program which calculates time optical geocentric transfers using solar or nuclear electric and high thrust propulsion

This manual is a guide for using a computer program which calculates time optimal trajectories for high-and low-thrust geocentric transfers. Either SEP or NEP may be assumed and a one or two impulse, fixed total delta V, initial high thrust phase may be included. Also a single impulse of specified delta V may be included after the low thrust state. The low thrust phase utilizes equinoctial orbital elements to avoid the classical singularities and Kryloff-Boguliuboff averaging to help insure more rapid computation time. The program is written in FORTRAN 4 in double precision for use on an IBM 360 computer. The manual includes a description of the problem treated, input/output information, examples of runs, and source code listings.

Sackett, L. L.↗
NASA NTRS1982

GRID3C: Computer program for generation of C type multilevel, three dimensional and boundary conforming periodic grids

A fast computer program, GRID3C, was developed for accurately generating periodic, boundary conforming, three dimensional, consecutively refined computational grids applicable to realistic axial turbomachinery geometries. The method is based on using two functions to generate two dimensional grids on a number of coaxial axisymmetric surfaces positioned between the centerbody and the outer radial boundary. These boundary fitted grids are of the C type and are characterized by quasi-orthogonality and geometric periodicity. The built in nonorthogonal coordinate stretchings and shearings cause the grid clustering in the regions of interest. The stretching parameters are part of the input to GRID3C. In its present version GRID3C can generate and store a maximum of four consecutively refined three dimensional grids. The output grid coordinates can be calculated either in the Cartesian or in the cylindrical coordinate system.

Dulikravich, D. S.↗
NASA NTRS1983

The NCOREL computer program for 3D nonlinear supersonic potential flow computations

An innovative computational technique (NCOREL) was established for the treatment of three dimensional supersonic flows. The method is nonlinear in that it solves the nonconservative finite difference analog of the full potential equation and can predict the formation of supercritical cross flow regions, embedded and bow shocks. The method implicitly computes a conical flow at the apex (R = 0) of a spherical coordinate system and uses a fully implicit marching technique to obtain three dimensional cross flow solutions. This implies that the radial Mach number must remain supersonic. The cross flow solutions are obtained by using type dependent transonic relaxation techniques with the type dependency linked to the character of the cross flow velocity (i.e., subsonic/supersonic). The spherical coordinate system and marching on spherical surfaces is ideally suited to the computation of wing flows at low supersonic Mach numbers due to the elimination of the subsonic axial Mach number problems that exist in other marching codes that utilize Cartesian transverse marching planes.

Siclari, M. J.↗
NASA NTRS1984

Improved 2-dimensional-kinetics computer program

The analytical capability of the existing Two-Dimensional Kinetics (TDK)/Boundary Layer Module (BLM) computer program for performance of Orbit Transfer Vehicle (OTV) thrust chambers was examined. Areas which need further examination and improvement are the thick boundary layer inviscid core flow interaction and the related thrust loss calculation. To warrant highly accurate results the provision of the best available program input data is mandatory, as well as, the use of sophisticated modeling techniques to reduce computation time with advanced error control criteria. The simulation of wall shocks, Mach-shocks, and shocks induced by large concave wall curvature is essential since this interaction with each other produces flow field changes which in turn affect the nozzle performance.

Nickerson, G. R.↗
NASA NTRS1984

Improved two-dimensional-kinetics computer program

The objective of this research is to increase the analytical capability of the existing TDK/BLM computer program for performance of OTV thrust chambers. Areas which need further examination and improvement are the thick boundary layer inviscid core flow interaction and the related thrust loss calculation. To warrent highly accurate results the provision of the best available program input data is mandatory as well as the use of sophisticated modeling techniques to reduce computation time with advanced error control criteria. The simulation of wall shocks and Mach-shocks in addition to shocks induced by large concave wall curvature is essential since this interaction with each other produces flow field changes which in turn affect the nozzle performance.

Source record↗
NASA NTRS1995

A NASTRAN-based computer program for structural dynamic analysis of Horizontal Axis Wind Turbines

This paper describes a computer program developed for structural dynamic analysis of horizontal axis wind turbines (HAWT's). It is based on the finite element method through its reliance on NASTRAN for the development of mass, stiffness, and damping matrices of the tower end rotor, which are treated in NASTRAN as separate structures. The tower is modeled in a stationary frame and the rotor in one rotating at a constant angular velocity. The two structures are subsequently joined together (external to NASTRAN) using a time-dependent transformation consistent with the hub configuration. Aerodynamic loads are computed with an established flow model based on strip theory. Aeroelastic effects are included by incorporating the local velocity and twisting deformation of the blade in the load computation. The turbulent nature of the wind, both in space and time, is modeled by adding in stochastic wind increments. The resulting equations of motion are solved in the time domain using the implicit Newmark-Beta integrator. Preliminary comparisons with data from the Boeing/NASA MOD2 HAWT indicate that the code is capable of accurately and efficiently predicting the response of HAWT's driven by turbulent winds.

Lobitz, Don W.↗