46,104 research outputs found

    Numerical prediction of 3-D ejector flows

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    The use of parametric flow analysis, rather than parametric scale testing, to support the design of an ejector system offers a number of potential advantages. The application of available 3-D flow analyses to the design ejectors can be subdivided into several key elements. These are numerics, turbulence modeling, data handling and display, and testing in support of analysis development. Experimental and predicted jet exhaust for the Boeing 727 aircraft are examined

    Water velocity meter

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    Simple, inexpensive drag sphere velocity meter with a zero to 6 ft/sec range measures steady-state flow. When combined with appropriate data acquisition system, it is suited to applications where large numbers of simultaneous measurements are needed for current mapping or velocity profile determination

    Secondary flow spanwise deviation model for the stators of NASA middle compressor stages

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    A model of the spanwise variation of deviation for stator blades is presented. Deviation is defined as the difference between the passage mean flow angle and the metal angle at the outlet of a blade element of an axial compressor stage. The variation of deviation is taken as the difference above or below that predicted by blade element, (i.e., two-dimensional) theory at any spanwise location. The variation of deviation is dependent upon the blade camber, solidity and inlet boundary layer thickness at the hub or tip end-wall, and the blade channel aspect ratio. If these parameters are known or can be calculated, the model provides a reasonable approximation of the spanwise variation of deviation for most compressor middle stage stators operating at subsonic inlet Mach numbers

    Mission Requirements for Exobiological Measurements on Venus

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    Mission planning for exobiological measurements on Venu

    A search for a superconducting effect on alpha particle differential energy loss in type 1 superconductors

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    Superconducting effects on alpha particle differential energy loss in tin, vanadium, and lead superconductor

    A STUDY OF CRYOPUMP CONFIGURATIONS IN FREE MOLECULAR FLOW REGIONS

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    Monte carlo computer technique applied to focusing of cryopump configurations in free molecular flow regio

    An Expansion Term In Hamilton's Equations

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    For any given spacetime the choice of time coordinate is undetermined. A particular choice is the absolute time associated with a preferred vector field. Using the absolute time Hamilton's equations are −(δHc)/(δq)=π˙+Θπ,- (\delta H_{c})/(\delta q)=\dot{\pi}+\Theta\pi, + (\delta H_{c})/(\delta \pi)=\dot{q},where, where \Theta = V^{a}_{.;a}istheexpansionofthevectorfield.Thusthereisahithertounnoticedtermintheexpansionofthepreferredvectorfield.Hamilton′sequationscanbeusedtodescribefluidmotion.Inthiscasetheabsolutetimeisthetimeassociatedwiththefluid′sco−movingvector.Asmeasuredbythisabsolutetimetheexpansiontermispresent.Similarlyincosmology,eachobserverhasaco−movingvectorandHamilton′sequationsagainhaveanexpansionterm.ItisnecessarytoincludetheexpansiontermtoquantizesystemssuchastheabovebythecanonicalmethodofreplacingDiracbracketsbycommutators.Hamilton′sequationsinthisformdonothaveacorrespondingsympleticform.Replacingtheexpansionbyaparticlenumber is the expansion of the vector field. Thus there is a hitherto unnoticed term in the expansion of the preferred vector field. Hamilton's equations can be used to describe fluid motion. In this case the absolute time is the time associated with the fluid's co-moving vector. As measured by this absolute time the expansion term is present. Similarly in cosmology, each observer has a co-moving vector and Hamilton's equations again have an expansion term. It is necessary to include the expansion term to quantize systems such as the above by the canonical method of replacing Dirac brackets by commutators. Hamilton's equations in this form do not have a corresponding sympletic form. Replacing the expansion by a particle number N\equiv exp(-\int\Theta d \ta)andintroducingtheparticlenumbersconjugatemomentum and introducing the particle numbers conjugate momentum \pi^{N}thestandardsympleticformcanberecoveredwithtwoextrafieldsNand the standard sympletic form can be recovered with two extra fields N and \pi^N$. Briefly the possibility of a non-standard sympletic form and the further possibility of there being a non-zero Finsler curvature corresponding to this are looked at.Comment: 10 page

    Weighing scales for sheep do pay

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    Sheep producers can improve production by using weighing scales and keeping accurate records of weights. Withiut some objective measurement, such as weighing, producers have no accurate method of identifying the heaviest, lightest and average weight of a group of sheep. They could try to esstimate weight by eye - but most people are poor judges of body weight

    The surveillance of Annual Ryegrass Toxicity in Western Australia October 1991 to May 1992

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    Between October 1991 and January 1992 (1991 Annual Ryegrass Toxicity(ARGT) season) 89 farms reported a total of 102 outbreaks of ARGT to the Department of Agriculture Western Australia. This second annual report provides summary information on these occurrences. The main body of the report focuses on mortality records collected by Departmental advisory staff when farmers sought information on ARGT during this period
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