IMP I spacecraft initial magnetic test
Initial magnetic test of IMP-I spacecraft with reduction of magnetic moment by dc rotation deperm treatments
Eichhorn, W. L.↗
SEARCH · Engineering Papers
Results for “initial”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Solution of an initial-value problem in linear transport theory - Monoenergetic neutrons in a slab with infinite reflectors
Solution of initial value problem in linear transport theory obtained by monoenergetic neutrons migrating in thin slab with infinite reflector and isotropic scattering
Bowden, R. L.↗
Crack initiation at stress concentrations as influenced by prior local plasticity
Notched metal crack initiation, determining high cyclic loads effects by prior local plastic behavior at stress concentration
Crews, J. H., Jr.↗
Decay of homogeneous turbulence from a given initial state
Homogeneous turbulence decay formulation using multipoint velocity correlations, initial time derivatives and time evolution
Deissler, R. G.↗
Influence of initial flow direction on the turbulent base pressure in supersonic axisymmetric flow
Turbulent base pressure on conical afterbodies in supersonic axisymmetric flow, including initial direction effect
Hall, C. R., Jr.↗
A mechanism for the initiation of detonation in hydrazine/nitrogen tetroxide pulse-mode engine residues
Nitrogen tetroxide/hydrazine pulse mode rocket engines structural failure due to chemically reactive gaseous hot spots causing high pressure spiking and detonation initiation
Mclain, W. H.↗
The control of initiation of food intake by body-fluid osmolality
Body fluid osmolality control of food intake initiation in rehydrated rats injected with hypertonic sodium chloride solution
Deaux, E.↗
Decay of homogeneous turbulence from a given initial state
Homogeneous turbulence decay calculation from multipoint velocity correlations or spectral equivalents at initial time
Deissler, R. G.↗
Self-correcting initial value formulations in nonlinear structural mechanics
Nonlinear static structural mechanical problems solution, using self correcting initial value formulations
Haisler, W. E.↗
Shock-tube study of the initiation process in the hydrogen-oxygen reaction
Shock wave initiation of hydrogen-oxygen at 1200-1800 K, using UV absorption spectroscopy in shock tube studies
Houghton, W. M.↗
Modular space station phase B extension preliminary performance specification. Volume 1: Initial station systems
The general, operational, design/construction, and subsystem design requirements are presented for a solar powered modular space station system. While these requirements apply only to the initial station system, the system is readily adaptable to a growth configuration.
Source record↗
A finite element procedure for nonlinear prebuckling and initial postbuckling analysis
A procedure cast in a form appropriate to the finite element method is presented for geometrically nonlinear prebuckling and postbuckling structural analysis, including the identification of snap-through type of buckling. The principal features of this procedure are the use of direct iteration for solution of the nonlinear algebraic equations in the prebuckling range, an interpolation scheme for determination of the initial bifurcation point, a perturbation method in definition of the load-displacement behavior through the postbuckling regime, and extrapolation in determination of the limit point for snap-through buckling. Three numerical examples are presented in illustration of the procedure and in comparison with alternative approaches.
Mau, S. T.↗
Experimental investigation of an axisymmetric free jet with an initially uniform velocity profile
An experimental investigation was conducted to determine the flow characteristics of a circular free helium jet having an initially uniform velocity profile. Complete velocity profiles are presented at Reynolds numbers of 1027 and 4571 at 0, 3, 6, 10, 15, and 20 nozzle diameters (where possible) from the nozzle exit. Centerline velocity decay and potential core length were obtained over a range of Reynolds numbers from 155 to 5349 at distances up to and including 25 nozzle diameters from the nozzle exit. The angles of spread associated with the diffusion of the jet downstream of the nozzle are also given. Axial jet momentum flux and entrained mass flux, at various distances downstream of the nozzle, are presented as a function of the jet Reynolds number.
Labus, T. L.↗
Liquid inflow to initially empty cylindrical tanks in low gravity
An experimental investigation was performed to determine the characteristics of liquid inflow to initially empty cylindrical tanks in a low gravity environment. The acceleration was varied so that Bond numbers based on the inlet radius varied from 0.059 to 2.80. The liquid entered the tank as a jet that grew to a maximum height and then decreased in height with respect to the bottom of the tank, with the liquid from the jet collecting in the bottom of the tank. The maximum jet heights were correlated in terms of the Weber number and the Bond number.
Spuckler, C. M.↗
Initial development of a hypersonic free mixing layer
A preliminary experimental investigation to establish some of the characteristics and further the understanding of the initial development of a turbulent free mixing layer for hypersonic speeds has been conducted. Mean profile data at about 6 inches downstream of the exit of a hypersonic nozzle have been obtained in nitrogen for a nominal Mach number of 19.5, total temperature of about 1670 K and Reynolds number range from about 50,000 to 110,000 per foot and have been compared with profiles upstream of the nozzle exit. Static pressure varied across the shear layer for the present tests. The outer 80 percent of the high-velocity portion of the free shear layer can be calculated by a rotational method of characteristics. However, turbulent mixing is evidently important in the low-velocity region, and effects of eddy viscosity and eddy conductivity should be included in a theoretical analysis.
Harvey, W. D.↗
Reduction of the Dirichlet problem to an initial value problem.
Although the derivation is concerned with solutions for plane regions with prescribed boundary values, the approach presented could by easily generalized to higher dimensions. The initial-value method is derived by a combination of invariant imbedding techniques and the Fredholm integral equation method of representation of the potential as a function of a dilayer distribution on the boundary of the region in question.
Kalaba, R.↗
Effect of initial hydrogen content of a titanium alloy on susceptibility to hot salt stress corrosion.
The influence of the initial hydrogen content of a titanium alloy on subsequent resistance to hot salt stress corrosion embrittlement and cracking was investigated. A Ti-8Al-1Mo-1V alloy was tested in four conditions: mill annealed (70 ppm H), duplex annealed (70 ppm H), vacuum annealed to an intermediate (36 ppm H) and a low (9 ppm H) hydrogen level. Material annealed at 650 C (duplex condition) exhibited resistance to hot salt stress corrosion superior to that exhibited by material in the mill annealed condition. Reduction of the alloy hydrogen content from 70 to as low as 9 ppm did not influence resistance to hot salt stress corrosion embrittlement or cracking.
Gray, H. R.↗
U-Th-Pb systematics in three Apollo 14 basalts and the problem of initial Pb in lunar rocks.
The isotopic composition of Pb and the elemental concentration of U, Th and Pb were measured on 'total' rock samples 14053, 14073 and 14310 and on mineral separates of 14310 and 14053. These are the first Pb-U isochrons obtained for lunar basalts and indicate a reasonable solution to the previous discrepancy between the different methods of 'absolute' age determination. The resulting U-Pb isochron ages are compatible with the Rb-Sr and K-Ar ages on the same rocks. However, it is not possible to establish a precise time of 'crystallization' from the Pb-U data because of the small angle of intersection between the linear arrays and the concordia curve. These data show that total rock model ages do not in general yield crystallization ages. The data on 14310 and 14053 show that these rocks were formed containing a highly radiogenic initial lead which accounts for the excessively high total rock model ages by the U-Th-Pb method. The data prove that at the time of extrusion of some basalts, unsupported lead with extremely high Pb-207/Pb-206 ratios was added to the lunar surface.
Tera, F.↗