115,741 research outputs found

    The Applications Technology Satellite apogee rocket motor - A summary report

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    Design, testing, and development of solid propellant rocket engine for orbital transfer of Applications Technology Satellit

    Vacuum Polarisation and the Black Hole Singularity

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    In order to investigate the effects of vacuum polarisation on mass inflation singularities, we study a simple toy model of a charged black hole with cross flowing radial null dust which is homogeneous in the black hole interior. In the region r2≪e2r^2 \ll e^2 we find an approximate analytic solution to the classical field equations. The renormalized stress-energy tensor is evaluated on this background and we find the vacuum polarisation backreaction corrections to the mass function m(r)m(r). Asymptotic analysis of the semiclassical mass function shows that the mass inflation singularity is much stronger in the presence of vacuum polarisation than in the classical case.Comment: 12 pages, RevTe

    Qualification Phase for the Applications Technology Satellite Apogee Rocket Motor Technical Memorandum, Jul. - Aug. 1966

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    Qualifications tests on applications technology satellite apogee rocket motor assemblie

    Design considerations for the airframe-integrated scramjet

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    Research programs at the NASA Langley Research Center on the development of airframe-integrated scramjet concepts (supersonic combustion ramjet) are reviewed briefly. The design and performance of a specific scramjet configuration are examined analytically by use of recently developed and substantiated techniques on boundary-layer development, heat transfer, fuel-air mixing, heat-release rates, and engine-cycle analysis. These studies indicate that the fixed-geometry scramjet module will provide practical levels of thrust performance with low cooling requirements. Areas which need particular emphasis in further development work are the combustor design for low speeds and the integrated nozzle design

    Evaluation of a bulk calorimeter and heat balance for determination of supersonic combustor efficiency

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    Results are presented from the shakedown and evaluation test of a bulk calorimeter. The calorimeter is designed to quench the combustion at the exit of a direct-connect, hydrogen fueled, scramjet combustor model, and to provide the measurements necessary to perform an analysis of combustion efficiency. Results indicate that the calorimeter quenches reaction, that reasonable response times are obtained, and that the calculated combustion efficiency is repeatable within + or -3 percent and varies in a regular way with combustor model parameters such as injected fuel equivalence ratio

    Improving fertiliser management: redefining the relationship between soil tests and crop responses for wheat in WA

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    Most soils in Western Australia (WA) are highly weathered with very low levels of phosphorus. WA soils initially contained adequate indigenous soil potassium for cropping but removal of potassium over time in harvested grain has gradually resulted in the some soils becoming potassium-deficient for grain production. Fertiliser costs represent a significant part of the variable costs of growing crops in WA. Chen et al. (2009) identified the need for updated soil test interpretations due to substantial changes in farming systems, fertiliser practices and crop yield potential. The aims of this study were (1) to compile experimental data containing the standard soil test measurements and observed wheat crop yield responses for both nil and fertilised treatments across different soil types and seasons from published or unpublished sources, and (2) to critically analyse soil test-crop response relationships to derive better critical soil test values in soils and environments suitable for wheat grain production in WA

    Superfluid Transition in a Chiron Gas

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    Low temperature measurements of the magnetic susceptibility of LSCO suggest that the superconducting transition is associated with the disappearance of a vortex liquid. In this note we wish to draw attention to the fact that spin-orbit-like interactions in a poorly conducting layered material can lead to a new type of quantum ground state with spin polarized soliton-like charge carriers as the important quantum degree of freedom. In 2-dimensions these solitons are vortex-like, while in 3-dimensional systems they are monopole-like. In either case there is a natural mechanism for the pairing of spin up and spin down solitons, and we find that at low temperatures there is a cross-over transition as a function of carrier density between a state where the solitons are free and a condensate state where the spin up and spin down solitons in neighboring layers are paired.Comment: 10 pages, 1 figur

    Calculation of flow about posts and powerhead model

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    A three dimensional analysis of the non-uniform flow around the liquid oxygen (LOX) posts in the Space Shuttle Main Engine (SSME) powerhead was performed to determine possible factors contributing to the failure of the posts. Also performed was three dimensional numerical fluid flow analysis of the high pressure fuel turbopump (HPFTP) exhaust system, consisting of the turnaround duct (TAD), two-duct hot gas manifold (HGM), and the Version B transfer ducts. The analysis was conducted in the following manner: (1) modeling the flow around a single and small clusters (2 to 10) of posts; (2) modeling the velocity field in the cross plane; and (3) modeling the entire flow region with a three dimensional network type model. Shear stress functions which will permit viscous analysis without requiring excessive numbers of computational grid points were developed. These wall functions, laminar and turbulent, have been compared to standard Blasius solutions and are directly applicable to the cylinder in cross flow class of problems to which the LOX post problem belongs
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