Computer program to predict heat transfer through glass.
Thermal behavior of space vehicle window systems predicted by mathematical analysis and computer methods for heat transfer through glass
Comstock, D. F.↗
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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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Constitutive relations for stress and heat flux in a shock wave
Mathematical analysis of shock wave structure incorporating Maxwell moment methods and Boltzmann equation for stress and heat flux constitutive relations
Baganoff, D.↗
Summary of available information on Reynolds analogy for zero-pressure-gradient, compressible, turbulent-boundary-layer flow
Mathematical analysis of Reynolds analogy for turbulent heat transfer, skin friction, and boundary layer flow in adiabatic conditions
Cary, A. M., Jr.↗
An improved analytical treatment of the denting of thin sheets by hail
Mathematical analysis of denting of thin aircraft skin by hail
Hayduk, R. J.↗
Automated preliminary design of simplified wing structures to satisfy strength and flutter requirements
A simple structural model of an aircraft wing is used to show the effects of strength (stress) and flutter requirements on the design of minimum-weight aircraft-wing structures. The wing is idealized as an isotropic sandwich plate with a variable cover thickness distribution and a variable depth between covers. Plate theory is used for the structural analysis, and piston theory is used for the unsteady aerodynamics in the flutter analysis. Mathematical programming techniques are used to find the minimum-weight cover thickness distribution which satisfies flutter, strength, and minimum-gage constraints. The method of solution, some sample results, and the computer program used to obtain these results are presented. The results indicate that the cover thickness distribution obtained when designing for the strength requirement alone may be quite different from the cover thickness distribution obtained when designing for either the flutter requirement alone or for both the strength and flutter requirements concurrently. This conclusion emphasizes the need for designing for both flutter and strength from the outset.
Stroud, W. J.↗
A nonlinear-coherence receiver
Mathematical analysis and detailed study of generic model for coherent receiver has demonstrated that nonlinear coherence between given biphase-modulated input signal and supplied reference signal can be used in receivers to improve telecommunication systems.
Simon, M. K.↗
Dynamic technique for measuring adsorption in a gas chromatograph
Gas-chromatographic procedure, together with mathematical analysis of adsorption isotherm, allows relative surface areas and adsorptive powers for trace concentrations to be determined in a few minutes. Technique may be used to evaluate relative surface areas of different adsorbates, expressed as volume of adsorbent/gram of adsorbate, and to evaluate their relative adsorptive power.
Deuel, C. L.↗
Effect of filtering on noise and timing in nuclear particle detection
The relations between signal shaping, noise, and timing resolution in nuclear particle detection systems are examined in this paper. Mathematical analysis of five commonly used types of filters leads to numerical results for system noise components arising from sources in the preamplifier, detector, and bias resistors. These results are presented in the form of design curves for the various filters, showing the dependence of each output noise component on both the magnitude of the noise sources and the filter time constants. Three of the filters considered are simple RC types; the remaining two are combinations of delay lines and RC elements. The quantitative calculations specifically assume a silicon detector and a field-effect-transistor preamplifier. Those filters that exhibit bipolar step response are analyzed in terms of crossover timing resolution, based on the earlier noise calculations. Again, the results are summarized in sets of design curves for each filter. Finally, the comparative performance of the various filter types is discussed, and specific examples are given.
Gary, S. A.↗
The transmission of sonic boom signals into rooms through open windows.
This paper is the second of two companion papers. In the first paper, expressions for the acoustic field generated inside a room with an open window due to incoming transient or periodic signals have been presented. In this paper, the technique has been applied to the specific example of an N-wave type signal. Detailed mathematical analysis is followed by its approximate version and numerical computation. Results of controlled experiments, using simulated sonic booms, have been compared with theoretical predictions.
Vaidya, P. G.↗
Launch window definition for sky target experiments.
This paper is a brief report on the computer program developed for the Extraterrestrial Physics Barium Ion Cloud (BIC) Project. The mathematical analysis developed for the program along with its programing characteristics are pointed out to show that this program is adaptable to similar sky target projects. Definite viewing constraints are specified so that the chosen ground tracking stations can photograph the behavior of the sky target after its release. Viewing factors include the illumination of the target by the sun, the relative elevation look angle to the target from each tracking station, the solar and lunar depression angles at each tracking station, and the total sky background brightness of the target relative to each tracking station. Numeric values are assigned to each factor through program input. The program output is flexible so that the results of the window calculations can be studied to the depth required.
Michaud, N. H.↗
Thermal expansion compatibility of ceramic chip capacitors mounted on alumina substrates.
The thermal expansion coefficients of a representative sample of BaTiO3 and TiO2 ceramic chip capacitors and alumina substrates have been examined. These data have revealed large potential mechanical stresses under thermal cycling. A mathematical analysis of a composite model of the capacitor to predict the thermal expansion and modulus of elasticity and an analysis of the capacitor-substrate system to predict the magnitude of thermally induced stresses have been conducted. In all cases studied, thermally induced stresses great enough to cause capacitor body rupture or termination failure was predicted.
Allen, R. V.↗
Mass-energy metabolic characteristics of algae
A mathematical analysis is given for the mass energy characteristics of photosynthesizing algae. An engineering-biological approach to this allows for a detailed analysis of the characteristics for a broad spectrum of environmental situations in which such algae are used as a component of a life support system. Models of such systems are constructed and are employed to demonstrate actual and hypothetical situations. Computers are employed for this purpose.
Smirnov, I. V.↗
RI 1170 advanced strapdown gyro
The major components of the RI 1170 gyroscope are described. A detailed functional description of the electronics including block diagrams and photographs of output waveshapes within the loop electronics are presented. An electronic data flow diagram is included. Those gyro subassemblies that were originally planned and subsequently changed or modified for one reason or another are discussed in detail. Variations to the original design included the capacitive pickoffs, torquer flexleads, magnetic suspension, gas bearings, electronic design, and packaging. The selection of components and changes from the original design and components selected are discussed. Device failures experienced throughout the program are reported and design corrections to eliminate the failure modes are noted. Major design deficiencies such as those of the MSE electronics are described in detail. Modifications made to the gas bearing parts and design improvements to the wheel are noted. Changes to the gas bearing prints are included as well as a mathematical analysis of the 1170 gas bearing wheel by computer analysis. The mean free-path effects on gas bearing performance is summarized.
Source record↗
A composite model for a class of electric-discharge shock tubes
A gasdynamic model is presented and analyzed for a class of shock tubes that utilize both Joule heating and electromagnetic forces to produce high-speed shock waves. The model consists of several stages of acceleration in which acceleration to sonic conditions is achieved principally through heating, and further acceleration of the supersonic flow is obtained principally through use of electromagnetic forces. The utility of the model results from the fact that it predicts a quasi-steady flow process, mathematical analysis is straightforward, and it is even possible to remove one or more component stages and still have the model related to a possible shock-tube flow. Initial experiments have been performed where the electrical discharge configuration and current level were such that Joule heating was the dominant form of energy addition present. These experiments indicate that the predictions of the model dealing with heat addition correspond quite closely to reality. The experimental data together with the theory show that heat addition to the flowing driver gas after diaphragm rupture (approach used in the model) is much more effective in producing high-speed shock waves than heating the gas in the driver before diaphragm rupture, as in the case of the arc-driven shock tube.
Elkins, R. T.↗
A stack algorithm for source coding with a fidelity criterion
Although coding of sources with respect to a fidelity criterion was first proposed by Shannon in 1959, only recently have effective schemes been developed. Another such algorithm based on a stack is described. Like the author's other algorithms (Jelinek and Anderson, 1971, 1973), this algorithm is conceived with tree codes in mind. It has various strengths and weaknesses relative to the earlier two, which are explored. By itself, the algorithm has an interesting mathematical analysis that yields insight into the faster-than-exponential behavior of tree variables and provides a new characterization of the rate-distortion function.
Anderson, J. B.↗
Thermal loading in the laser holography nondestructive testing of a composite structure
A laser holographic interferometry method that has variable sensitivity to surface deformation was applied to the investigation of composite test samples under thermal loading. A successful attempt was made to detect debonds in a fiberglass-epoxy-ceramic plate. Experimental results are presented along with the mathematical analysis of the physical model of the thermal loading and current conduction in the composite material.
Liu, H. K.↗
SUSSA ACTS: A computer program for steady and unsteady, subsonic and supersonic aerodynamics for aerospace complex transportation systems
The computer program SUSSA ACTS (Steady and Unsteady, Subsonic and Supersonic Aerodynamics for Complex Transportation Systems) are presented in the final version. The numerical formulation and the description of the program and numerical results are included. In particular, generalized forces for fully unsteady (complex frequency) aerodynamics for a wing-body configuration, in both subsonic and supersonic flows, are discussed. The mathematical analysis includes completely arbitrary motion. The numerical implementation was limited to steady and oscillatory flows. A more general aerodynamic formulation in the form of a fully transient response for time-domain analysis and the aerodynamic transfer function (Laplace transform of the fully unsteady operator) for frequency-domain analysis is outlined.
Tseng, K.↗
Monte Carlo variance reduction study
A mathematical analysis of the transport of nuclear radiation through matter is presented. A computer test bed that was developed is shown, along with flow charts.
Byrn, N. R.↗