Influence of controlled turbulence on gaseous discharges
Gas dynamics turbulence of controlled properties effect on electrical discharge across plasma stream, preventing filamentary nature
Argyropoulos, G. S.↗
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Magnetic and electric fields in the magnetosheath
Steady state magnetic and electric fields in magnetosheath by linear superposition of field vectors, using axisymmetric velocity function from gas dynamics
Alksne, A. Y.↗
Molecular energy transfer by fluid mixing Progress report, 1 Jan. 1968 - 1 Jan. 1971
CW chemical laser development, N2-C02 electrically excited fluid mixing laser techniques, and gas dynamic mixing behind shock waves
Cool, T. A.↗
Calculation of supersonic flows at large distances from slender lifting bodies
Solving exact gas dynamic equations for supersonic flows far from axis of slender lifting bodies
Schorling, M.↗
A subsonic transonic and supersonic nozzle flow by the inverse technique
Inverse solution of two dimensional gas dynamic flow fields of rotational or irrotational character
Norton, David J.↗
Laser power at 5 microns from the supersonic expansion of carbon monoxide
Laser power from carbon monoxide supersonic expansion in nitrogen and argon mixtures, comparing to carbon dioxide gas dynamic lasers
Mckenzie, R. L.↗
Some analytic solutions to the linearized Boltzmann equation with the ellipsoidal model
Linearized Boltzmann equation analytic solutions for rarefied gas dynamic problems, using ellipsoid model
Giddens, D. P.↗
Radiative-gasdynamic coupling and nonequilibrium effect behind reflected shock waves
Flowfields behind reflected shock waves, predicting end-wall pressure, radiative heat transfer and radiative gas dynamic coupling effects
Carlson, L. A.↗
Pulsed gasdynamic lasers
Pulsed gas dynamic laser for radiation generation at high power levels, using shock tube
Christiansen, W. H.↗
Technology of nuclear-Brayton space power systems
The present technology of Brayton power systems is reviewed. The potential for even higher system efficiency at the 10 KWe level is assessed as well as the potential for comparable efficiency with an output of 1 or 2 KWe. Systems accommodation of isotope decay is briefly discussed. The salient features are described for a Brayton power system based on this technology and employing the ZrH reactor. Reactor lives for this and competitive systems are compared. Growth capability with an advanced reactor is assessed. A concept for application of this technology to driving a gas-dynamic laser is described.
English, R. E.↗
Vibrational population distributions in nonequilibrium nozzle expansion flows
Experimental measurements and theoretical calculations of the vibrational population distribution in nonequilibrium nozzle expansion flows of gas mixtures are reported. These studies were directed toward determining whether vibrational energy exchange pumping could lead to laser action on the vibrational bands of a diatomic molecule. Three different types of experiments were conducted. These showed (1) that vibrational energy was preferentially transferred from N2 to CO in supersonic nozzle flows containing these gases; (2) that under some conditions this vibrational energy exchange pumping mechanism created population inversions in the vibrational levels of CO; and (3) that at large expansion ratios the magnitude of these population inversions was sufficient to sustain lasing in the nozzle. A theoretical model was developed to calculate vibrational state population distributions in gas dynamic expansions of a mixture of diatomic gases. Although only isothermal calculations have been completed, these data indicate that population inversions are predicted for conditions similar to those obtained in the nozzle expansion flows.
Watt, W. S.↗
Propellant sidefeed-short pulse discharge thruster studies
The technique of feeding a solid propellant into the discharge from the sides of the discharge was evaluated. The thrust/power ratio could be significantly effected by the included angle of V-shaped propellants and by the electrode length. This result implies that when results are compared at the same specific impulse it is possible to obtain higher thrust efficiencies. In particular, it was found that for a given discharge energy the thrust/power ratio correlated with propellant mass. Increasing the integral simultaneously increases both the gas dynamic and electromagnetic thrust. An analytic expression was formulated for ablated mass which comprehensively describes experimental data in terms of geometry and electrical parameters. The correlation of the product impulse x specific impulse with discharge energy was also described. It is suggested that the reliability of dry energy storage capacitors does not equal the reliability of liquid impregnated units when the comparison is made at the same joules/Kg rating.
Palumbo, D. J.↗
Numerical solution of flowfields behind rectangular wings
The numerical solution of flow fields behind rectangular wings is described. Subjects discussed are: (1) evaluation of various differencing methods applied to the hyperbolic partial differential equations encountered in gas dynamics, (2) application of the numerical differencing techniques to the wedge flow, two dimensional shock reflection for the three dimensional finite thickness wing at zero degrees angle of attack, and (3) calculation of preliminary results for wedge flows using optimum differencing methods.
Anderson, D.↗
Mission oriented R and D and the advancement of technology: The impact of NASA contributions, volume 2
NASA contributions to the advancement of major developments in twelve selected fields of technology are presented. The twelve fields of technology discussed are: (1) cryogenics, (2) electrochemical energy conversion and storage, (3) high-temperature ceramics, (4) high-temperature metals (5) integrated circuits, (6) internal gas dynamics (7) materials machining and forming, (8) materials joining, (9) microwave systems, (10) nondestructive testing, (11) simulation, and (12) telemetry. These field were selected on the basis of both NASA and nonaerospace interest and activity.
Robbins, M. D.↗
Heat transfer tests of the McDonnell-Douglas delta wing orbiter mated with -17A booster at Mach number 8
A wind tunnel test program to determine aerodynamic heat transfer distributions on the McDonnell-Douglas configurations is reported. The tests were conducted at the Arnold Engineering Development Center (AEDC) in Tunnel B of the von Karman Gas Dynamics Facility (VKF). Heat-transfer rates were determined by the phase-change paint technique on 0.011-scale Stycast models using Tempilaq as the surface temperature indicator. The nominal test conditions were; Mach 8, freestream unit Reynolds numbers of 0.8 x one million, 2.5 x one million, and 3.7 x one million, and angles of attack of -5 deg, 0 deg, +5deg. Model details, test conditions, phase-change paint photographs and reduced heat-transfer coefficients are presented.
Matthews, R. K.↗
Technology of nuclear-Brayton space power systems.
The present technology of Brayton power systems is reviewed. The potential for even higher system efficiency at the 10 kWe level is assessed as well as the potential for comparable efficiency with an output of 1 or 2 kWe. System accommodation of isotope decay is briefly discussed. The salient features are described for a Brayton power system based on this technology and employing the ZrH reactor. Reactor lives for this and competitive systems are compared. Growth capability with an advanced reactor is assessed. A concept for application of this technology to driving a gas-dynamic laser is described.
English, R. E.↗
A systematic exposition of the conservation equations for blast waves.
In order to provide a rational background for the analysis of experimental observations of blast wave phenomena, the conservation equations governing their nonsteady flow field are formulated in a general manner, without the usual restrictions imposed by an equation of state, and with proper account taken, by means of source terms, of other effects which, besides the inertial terms that conventionally dominate these equations, can affect the flow. Taking advantage of the fact that a blast wave can be generally considered as a spatially one-dimensional flow field whose nonsteady behavior can be regarded, consequently, as a function of just two independent variables, two generalized blast wave coordinates are introduced, one associated with the front of the blast wave and the other with its flow field. The conservation equations are accordingly transformed into this coordinate system, acquiring thereby a comprehensive character, in that they refer then to any frame of reference, being applicable, in particular, to problems involving either space or time profiles of the gas-dynamic parameters in the Eulerian system, or time profiles in the Lagrangian system.
Oppenheim, A. K.↗
Sonic-boom calculation in a stratified atmosphere.
For a lifting body of revolution, the exact solutions to the gas dynamical equation are given for the flow field in a stratified atmosphere. The boundary condition is satisfied by using the (linearized) slender-body theory. The solution allows one to make a prediction of the magnitude and the location of the sonic boom in a stratified atmosphere as well as to handle cutoff effects.
Schorling, M.↗