Engineering topics
Publications and source records attributed to Smith, F. J..
Investigation was made to optimize selection of insulation materials for reusable space vehicles which will be repeatedly operated over periods of up to ten years. Results of study are summarized in two reports. Volume I describes tests and significant findings. In Volume II, extensive test data obtained are organized in handbook form.
Twenty candidate multilayer insulation and insulation related materials were subjected to eight conditions that represent possible operational environments. These exposures include ground contaminants, various operational temperatures, space vacuum, space-vented propellants, and tank leakage. The objective of this program was to obtain and evaluate the data from these exposures to provide both a quantitative and qualitative description of the degradation to certain physical and thermal properties, and from this, to obtain a better understanding of the environmental effects on the insulation performance.
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Experimental investigation of the effects of exposure of insulation materials to ground and space environments. A total of 20 materials were investigated. Mechanical and thermophysical data were obtained after exposures and were compared with control data. The most significant result of this program is the demonstration that the majority of the materials were not substantially changed by the environments.
A core model, consisting of a (12-4) central potential displaced from the origin, is suggested as a representation of the interaction of polyatomic ions with neutral molecules. The diffusion collision integral, which describes ion mobility, is computed and tabulated as a function of temperature and core size. The addition of the core reduces the maximum in the mobility against temperature curve, and eventually reduces the mobility below its polarization limit at all temperatures. These results are in accord with limited available experimental data. Comparison is made with other models of ion-neutral interactions.
Determination of a new set of values for the coefficients of viscosity and thermal conductivity of atomic hydrogen in the range from 1 to 100,000 K. The estimated error is about 5%. Quantal theory was used for low temperatures and classical theory for high temperatures. There is excellent agreement between the two theories as low as 20 K.-
Ionized gases quantum transport cross sections and collision integrals, considering energy and temperature ranges for attractive and repulsive screened Coulomb potentials
Epoxy/glass test specimens representing Scout fourth and fifth stage motor casings were prepared and studied in a test program designed to determine the relative contamination contributed to payload sensors located near the motor casings. The relative contamination detected in the test program was dependent on several factors, including: (1) distance of test specimen to sensor, (2) sensor temperature, (3) geometric position of the sensor (relative to test specimen), (4)test specimen temperature, (5) chemical composition of the test specimen, (6) sensor function, and (7) additional materials (such as adhesive-backed aluminum tape) added to the test specimens. The thermal characteristics and the decomposition and outgassing products were determined. These data were used to better understand the relative contamination data from the remote sensor testing.
Dilute gas transport properties calculation, investigating numerical techniques to minimize computation time to prescribed accuracy
Emissivity coatings for low temperature space radiators
Calorimetric measurement of source and broadband spectral absorptances of spacecraft thermal control coatings during exposure to UV in vacuum environment
Algorithm for definite integrals evaluation, using Clenshaw-Curtis and Romberg quadratures combination in each subinterval
Viscosity and thermal conductivity of atomic hydrogen
Numerical techniques for minimizing computation time for determining transport properties of dilute gas
Algorithm for efficient evaluation of badly behaved definite integrals to prescribed accuracy by concentrating abscissas near regions of most irregularity in integrand
Collision integrals for high temperature gases calculated for high order potentials
Chapman-Enskog transport collision integrals calculated for repulsive and attractive screened Coulomb potentials in ionized gases
Calorimetric measurement of source and broadband spectral absorptances of spacecraft thermal control coatings during exposure to UV in vacuum environment