29,913 research outputs found
Continuous-flow variable-density wind tunnel facilities
Unique features of wind tunnel facilities at Jet Propulsion Laboratory permit variety of conventional and novel tests to be performed at supersonic and hypersonic speeds. Facilities and operations are described
Rocket plume properties measured in space simulators
Molecular sink facility and 25-foot space simulator have been used to distinguish nature of exhaust plumes from nozzles with relatively large internal boundary layer flow. Plume density has been measured by electron beam/photomultiplier system
Gravitational collapse: A case for thermal relaxation
Two relativistic models for collapsing spheres at different stages of
evolution, which include pre-relaxation processes, are presented. The influence
of relaxation time on the outcome of evolution in both cases is exhibited and
established. It is shown that relaxation processes can drastically change the
final state of the collapsing system. In particular, there are cases in which
the value of the relaxation time determines the bounce or the collapse of the
sphere.Comment: 33 pages, LaTex 2.09, 11 Postscript figures. To be published in
General Relativity and Gravitatio
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