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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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Propellant sloshing in cylindrical tanks of space vehicles in low gravity fields - computer program
Vacuum metrics with null geodetic expanding shear- free congruences using holomorphic solution
General relativistic equations for stationary axially symmetric rotating perfect fluid in comoving coordinate system
Existence theorem concerning arbitrarily long good binary block /nonlinear/ codes preserved under large permutation groups
Model describing symmetrical information processing along visual pathways of brain
Sm double plus ion sites distribution in KCl by spectroscopy
Analytic expressions for axial and radial electric fields in axisymmetric interaction gaps of klystrons and coupled cavity traveling wave tubes are derived. Introduction of the field shape parameter m results in both limiting cases of the field at the tunnel tips, that is, E equal to a constant and E approaching infinity as well as a continuous transition between these two limits. The transition represents actual, practical fields. This representation may be used to replace the somewhat arbitrary expressions being applied by various researchers to describe the fields.
The feasibility of designing short curved wall axially symmetrical subsonic diffusers utilizing suction through slots in the diffuser walls to prevent flow separation was investigated. A potential flow analysis was made, and a digital computer program was written for determining the diffuser wall contour for prescribed boundary conditions. The flow field included branch flow so that the suction slot geometry could be a part of the diffuser design. One bell shaped diffuser and three annular diffusers with area ratios of either 2.5:1 or 3:1 were designed, fabricated, and tested. Minimum suction requirements of metastable operation ranged from 6.3 percent to 12 percent when operating with inlet air velocities in the 1000 to 250 ft/sec (30 to 76 m/sec) range. For stable operation suction rates from 10 percent to 22 percent were required. In all cases the diffuser effectiveness was above 95 percent based on the conventional definition, and from 81 percent to 94 percent when the suction loss was accounted for. The exit velocity profiles were virtually flat with no more than + or - 9% variation over 95 percent of the exit area when operated with sufficient suction to prevent flow separation.
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The validity of 'effective cone analysis' in estimating the boundary-layer properties of bodies in hypersonic flow is discussed. Simple formulas are derived for noncircular cones at angles of attack and are used to show that effective cone analysis only accounts for the increase in the local edge Reynolds number due to the angle of attack. A correction factor depending on the cross flow produced by the transverse curvature of the body and on the angle of attack is shown to reconcile the effective cone approach with the predictions of exact theory.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Frequently a photograph received from a spacecraft will be smeared by some process, e.g., by camera motion. Algebraically such smearing can be represented as p = sigma f, where sigma is the true picture, p is the received picture, and f is the smearing function. (p, sigma, and f are polynomials in two variables x and y.) Thus, in principle, sigma can be recovered by multiplying p by 1/f. However, there are problems involved in computing 1/f. Some of these problems are investigated.
The theoretical heat-transfer distributions are compared with experimental heat-transfer distributions obtained in Tunnel B at AEDC using a 0.0175 scale model of the space shuttle orbiter configuration for which the first 80% of the windward surface was roughened by a simulated tile misalignment. The theoretical solutions indicate that thinning the boundary layer by surface cooling increased the nondimensionalized value of the local heat-transfer coefficient. Tile misalignment did not significantly affect the heat-transfer rate in regions where the boundary layer was either laminar or turbulent.