55,754 research outputs found
Numerical prediction of 3-D ejector flows
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
Multibody Interplanetary Swingby Trajectories /MIST-1/
Computer program incorporates new isolation procedure to determine interplanetary trajectories which utilize a maximum of three flybys. Program also computes singe planet flybys and direct transfer trajectories. The three principle systems employed in MIST-1 use as their fundamental plane the mean plane of the earth's orbit around the sun
Development of and dynamic studies concerning a cable boom system prototype
The conception of a cable boom system for a scientific spin stabilized satellite led to a flat cable stowed on a drum with a flexlead without conversion to avoid slip rings and to facilitate automatic restowage from any state of deployment. Some dynamic features of the extended cable boom and especially the comparison between round and flat cables were investigated in a phenomenological study using a test rig capable of inducing lateral, torsional and thermal cycling disturbances separately or in any combination
Impact of dynamical chiral symmetry breaking on meson structure and interactions
We provide a glimpse of recent progress in meson physics made via QCD's
Dyson-Schwinger equations with: a perspective on confinement and dynamical
chiral symmetry breaking (DCSB); a pre'cis on the physics of in-hadron
condensates; results for the masses of the \pi, \sigma, \rho, a_1 mesons and
their first-radial excitations; and an illustration of the impact of DCSB on
the pion form factor.Comment: 6 pages, 3 figures, 1 table. Contribution to Proceedings of the 11th
International Workshop on Meson Production, Properties and Interaction,
Uniwersytet Jagiellonski, Instytut Fizyki, Krakow, Poland, 10-15 June 201
A microgravity isolation mount
The design and preliminary testing of a system for isolating microgravity sensitive payloads from spacecraft vibrational and impulsive disturbances is discussed. The Microgravity Isolation Mount (MGIM) concept consists of a platform which floats almost freely within a limited volume inside the spacecraft, but which is constrained to follow the spacecraft in the long term by means of very weak springs. The springs are realized magnetically and form part of a six degree of freedom active magnetic suspension system. The latter operates without any physical contact between the spacecraft and the platform itself. Power and data transfer is also performed by contactless means. Specifications are given for the expected level of input disturbances and the tolerable level of platform acceleration. The structural configuration of the mount is discussed and the design of the principal elements, i.e., actuators, sensors, control loops and power/data transfer devices are described. Finally, the construction of a hardware model that is being used to verify the predicted performance of the MGIM is described
Research into fundamental phenomena associated with spacecraft electrochemical devices, calorimetry of nickel-cadmium cells Progress report, 1 Oct. - 31 Dec. 1967
Calorimetry of nickel cadmium cells for spacecraft electrochemical system
Engineering evaluations and studies. Report for Ku-band studies, exhibit A
System performance aspects of the Ku band radar communication hardware and investigations into the Ku band/payload interfaces are discussed. The communications track problem caused by the excessive signal dynamic range at the servo input was investigated. The management/handover logic is discussed and a simplified description of the transmitter enable logic function is presented. Output noise produced by a voltage-controlled oscillator chip used in the SPA return-link channel 3 mid-bit detector is discussed. The deployed assembly (DA) and EA-2 critical design review data are evaluated. Cross coupling effects on antenna servo stability were examined. A series of meetings on the acceptance test specification for the deployed assembly is summarized
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