15 Fakultätsübergreifend / Sonstige Einrichtung

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/16

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    A numerical and experimental study of wavy ice structure in a parallel plate channel
    (1992) Weigand, Bernhard; Beer, Hans
    The paper presents a numerical model for predicting steady-state ice formation inside a cooled, parallel plate channel. The study takes into account the strong interactions occuring between the turbulent flow, the shape of the ice and the heat transfer at the ice-water interface, which lead to the formation of wavy ice layers. The presented model is found to be able to predict realistic variations of the ice layer thickness for a wide range of Reynolds numbers and cooling parameters. The numerical results were verified by comparing with own measurements and good agreement was found.
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    Towards a self-consistent modelling of pulsar magnetospheres
    (1987) Herold, Heinz; Ertl, Thomas; Finkbeiner, Bernd; Ruder, Hanns
    The numerical modelling of the general case of an oblique rotator is a very complicated time-dependent 3-dimensional problem and in its full extent probably outside the capicity of present.day computers. A considerable simplification occurs if one can assume that the essential effects may be understood by modelling the magnetosphere of an aligned rotator (where the rotation axis is parallel to the magnetic axis of the neutron star). This assumption is only reasonable for small obliqueness, since by this approach all electromagnetic wave effects are not taken into account.
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    Grebe/Bachems photometrische Analyse der Linienprofile und die Gravitations-Rotverschiebung : 1919 bis 1922
    (1992) Hentschel, Klaus
    An effort of proponents of relativity theory to find evidence for the so-called gravitational red-shift of spectral lines as one of the experimental consequences of Einstein's generalized theory of relativity is reconsidered with reference to hitherto unpublished documents. It is shown how much interest Albert Einstein in fact took, around 1920, in the data analysis of Leonhard Grebe and Albert Bachem, who tried to explain why most earlier efforts to find the gravitational red-shift had failed. They carefully measured the line profiles of the spectral lines both in the sun's Fraunhofer lines and in pressure-independent laboratory comparison spectra. Then they rejected all lines with strong neighbouring lines which could cause apparent shifts of the line centres; the remaining seven well-isolated lines showed the gravitational red-shift with acceptable accuracy. Nevertheless, their claim to have successfully isolated the relativistic effect never convinced the astrophysicists of their day - the reasons for the scientific community's scepticism, contrasted against the enthusiastic group of Einstein sympathizers, are also discussed.