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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Further studies on the dimensionless parameters associated with the 'in vivo' transport of heat within biological tissue.

Dimensionless parameters appearing in the analysis of transport of heat within living biological tissues are presented and discussed. Dimensional analysis as well as some analytical solutions have been employed to obtain the physically and physiologically most significant dimensionless parameters associated with these types of problems. Some analytical solutions are presented for both steady state and transient cases to illustrate the significance of the derived parameters.-

Shitzer, A.↗
NASA NTRS1972

Numerical isolation of flaws in the lunar theory.

The general concept of a numerical study of the lunar motion is examined and a particular case is discussed in greater detail than was possible in an earlier paper. Particular emphasis is placed upon the distinction to be made between model inadequacies and numerical artifacts, since either type of problem may be present in a given study, but the sensitivity to one or the other depends on the methodology used.

Mulholland, J. D.↗
NASA NTRS1972

Hamiltonian cosmology.

The study of cosmological models by means of equations of motion in Hamiltonian form is considered. Hamiltonian methods applied to gravity seem to go back to Rosenfeld (1930), who constructed a quantum-mechanical Hamiltonian for linearized general relativity theory. The first to notice that cosmologies provided a simple model in which to demonstrate features of Hamiltonian formulation was DeWitt (1967). Applications of the ADM formalism to homogeneous cosmologies are discussed together with applications of the Hamiltonian formulation, giving attention also to Bianchi-type universes. Problems involving the concept of superspace and techniques of quantization are investigated.

Ryan, M.↗
NASA NTRS1974

Design analysis and computer-aided performance evaluation of shuttle orbiter electrical power system. Volume 2: SYSTID user's guide

The manual for the use of the computer program SYSTID under the Univac operating system is presented. The computer program is used in the simulation and evaluation of the space shuttle orbiter electric power supply. The models described in the handbook are those which were available in the original versions of SYSTID. The subjects discussed are: (1) program description, (2) input language, (3) node typing, (4) problem submission, and (5) basic and power system SYSTID libraries.

Source record↗
NASA NTRS1975

Survey of decentralized control methods

An overview is presented of the types of problems that are being considered by control theorists in the area of dynamic large scale systems with emphasis on decentralized control strategies. Approaches that deal directly with decentralized decision making for large scale systems are discussed. It is shown that future advances in decentralized system theory are intimately connected with advances in the stochastic control problem with nonclassical information pattern. The basic assumptions and mathematical tools associated with the latter are summarized, and recommendations concerning future research are presented.

Athans, M.↗
NASA NTRS1977

Minor species and aerosols

A variety of species were measured to tie together the efforts of one dimensional and multidimensional models. The existence of critical species in the stratosphere was established. An attempt was made to establish some order to the measurements that were made and the type of problems that exist.

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NASA NTRS1977

Application of photometric analyses for interpretation of Mars-Mariner VI and VII imagery

The application of radiometric analysis in the interpretation of Mariner 6 and 7 imagery is investigated and illustrated. The following types of problems were felt could be addressed using this imagery: (1) evaluation of local reflectivity changes; (2) augmentation of geological mapping; (3) discrimination of atmospheric phenomena; and (4) investigation of polar cap structure.

Kinzly, R. E.↗
NASA NTRS1979

Application of direct-inverse techniques to airfoil analysis and design

The direct-inverse technique was developed into a numerical method, called TRANDES, that is suitable for the analysis and design of subsonic and transonic airfoils and for the evaluation of design concepts. A general description of the method is given and its application to a design analysis type of problem is demonstrated. A usage of the method for the low speed high lift case is discussed.

Carlson, L. A.↗
NASA NTRS1979

Important factors in the maximum likelihood analysis of flight test maneuvers

The information presented is based on the experience in the past 12 years at the NASA Dryden Flight Research Center of estimating stability and control derivatives from over 3500 maneuvers from 32 aircraft. The overall approach to the analysis of dynamic flight test data is outlined. General requirements for data and instrumentation are discussed and several examples of the types of problems that may be encountered are presented.

Iliff, K. W.↗
NASA NTRS1976

The NASTRAN demonstration program manual (level 16.0)

The types of problems that can be solved with NASTRAN are presented. The nature of the problem, the underlying theory, the specific geometric and physical input quanties, and the comparison of theoretical and NASTRAN results are discussed. At least one problem for each of the rigid formats and nearly all of the elements or provided. The features of NASTRAN demonstrated by specific problems are described. The results obtained are valid.

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NASA NTRS1978

Considerations in the analysis of flight test maneuvers

This paper discusses the application of a maximum likelihood estimator to dynamic flight-test data. The information presented is based on the experience in the past twelve years at the NASA Dryden Flight Research Center of estimating stability and control derivatives from over 3,000 maneuvers from 32 aircraft. The overall approach to the analysis of dynamic flight-test data is discussed. Detailed requirements for data and instrumentation are discussed and several examples of the types of problems that may be encountered are presented.

Iliff, K. W.↗
NASA NTRS1980

Heat conduction in three dimensions

Multidimensional heat conduction program computes transient temperature history and steady state temperatures of complex body geometries in three dimensions. Emphasis is placed on type of problems associated with Space Shuttle thermal protection system, but program could be used in thermal analysis of most three dimensional systems.

Danza, T. M.↗
NASA NTRS1980

Study of foldable elastic tubes for large space structure applications, phase 1

Structural members that might be suitable for strain energy deployable structures, are discussed with emphasis on a thin-walled cylindrical tube with a cross-section that is called 'bi-convex'. The design of bi-convex tube test specimens and their fabrication are described as well as the design and construction of a special purpose testing machine to determine the deployment characteristics. The results of the first series of tests were quite mixed, but clearly revealed that since most of the specimens failed to deploy completely, due to a buckling problem, this type of tube requires some modification in order to be viable.

Jones, I. W.↗
NASA NTRS1980

Thermal stress analysis of symmetric shells subjected to asymmetric thermal loads

The performance of the NASTRAN level 16.0 axisymmetric solid elements when subjected to both symmetric and asymmetric thermal loading was investigated. A ceramic radome was modeled using both the CTRAPRG and the CTRAPAX elements. The thermal loading applied contained severe gradients through the thickness of the shell. Both elements were found to be more sensitive to the effect of the thermal gradient than to the aspect ratio of the elements. Analysis using the CTRAPAX element predicted much higher thermal stresses than the analysis using the CTRAPRG element, prompting studies of models for which theoretical solutions could be calculated. It was found that the CTRAPRG element solutions were satisfactory, but that the CTRAPAX element was very geometry dependent. This element produced erroneous results if the geometry was allowed to vary from a rectangular cross-section. The most satisfactory solution found for this type of problem was to model a small segment of a symmetric structure with isoparametric solid elements and apply the cyclic symmetry option in NASTRAN.

Negaard, G. R.↗
NASA NTRS1979

Deep space mission integration with the space transportation system

The Galileo mission is the first interplanetary mission scheduled to use the Space Transportation System (STS). Therefore, Galileo is the trailblazer for mission integration of a deep space mission with the STS. A short overview of the Galileo mission is presented as background for the discussion of the mission integration effort. The components of the STS and the mission integration system are defined, documentation requirements explained, the work of the Flight Design Working Group described, and several examples of the types of problems dealt with are given. The steps of mission integration are shown from introducing requirements into the system to resolving conflicts that arise between the payload project and the STS operator. Conclusions are drawn from the Galileo mission integration effort to aid future payload projects in working with the STS.

Gray, W. B.↗
NASA NTRS1980

In search of other planetary systems

Numerous recent developments have led to an increasing awareness of and interest in the detection of other planetary systems. A brief review of the modern history of this subject is presented with emphasis on the status of data concerning Barnard's star. A discussion is given of plausible observable effects of other planetary systems with numerical examples to indicate the nature of the detection problem. Possible types of information (in addition to discovery) that observations of these effects might yield (e.g., planetary mass and temperature) are outlined. Also discussed are various candidate detection techniques (e.g., astrometric observations) which might be employed to conduct a search, the current state-of-the art of these techniques in terms of measurement accuracy, and the capability of existing or planned facilities (e.g., space telescope) to perform a search. Finally, consideration is given to possible search strategies and the scope of a comprehensive search program.

Black, D. C.↗