@inproceedings{FuttererZaussingerKrebsetal., author = {Futterer, Birgit and Zaussinger, Florian and Krebs, Andreas and Egbers, Christoph}, title = {Non-linear effects and associated instabilities in spherical Rayleigh-Benard experiments with variation of the viscosity contrast}, language = {en} } @inproceedings{FuttererZaussingerKochetal., author = {Futterer, Birgit and Zaussinger, Florian and Koch, Sandy and Krebs, Andreas and Egbers, Christoph}, title = {Nonlinear effects and associated instabilities in iso-viscous and temperature-dependent viscous thermal convection in spherical shells, the geophysical flow simulation experiment integrated in Fluid Science Laboratory}, language = {en} } @misc{FuttererZaussingerEgbersetal., author = {Futterer, Birgit and Zaussinger, Florian and Egbers, Christoph and Scurtu, Nicoleta}, title = {Variation of viscosity contrast for convection experiments in spherical shells as part of geophy-sical flow simulation experiment "GeoFlow II"}, language = {en} } @misc{Zaussinger, author = {Zaussinger, Florian}, title = {Semiconvection}, language = {de} } @misc{Zaussinger, author = {Zaussinger, Florian}, title = {Semiconvection}, language = {en} } @misc{FuttererKrebsPlesaetal., author = {Futterer, Birgit and Krebs, Andreas and Plesa, Ana-Catalina and Zaussinger, Florian and Hollerbach, Rainer and Breuer, Doris and Egbers, Christoph}, title = {Sheet-like and plume-like thermal flow in a spherical convection experiment performed under microgravity}, series = {Journal of Fluid Mechanics}, volume = {vol. 735}, journal = {Journal of Fluid Mechanics}, issn = {1750-6859}, doi = {10.1017/jfm.2013.507}, pages = {647 -- 683}, language = {en} } @misc{KupkaLoschZaussingeretal., author = {Kupka, Friedrich and Losch, Martin and Zaussinger, Florian and Zweigle, Thomas}, title = {Semi-convection in the ocean and in stars: A multi-scale analysis}, series = {Meteorologische zeitschrift}, volume = {24}, journal = {Meteorologische zeitschrift}, number = {3}, issn = {0941-2948}, doi = {10.1127/metz/2015/0643}, pages = {343 -- 358}, abstract = {Fluid stratified by gravitation can be subject to a number of instabilities which eventually lead to a flow that causes enhanced mixing and transport of heat. The special case where a destabilizing temperature gradient counteracts the action of a stabilizing gradient in molecular weight is of interest to astrophysics (inside stars and giant planets) and geophysics (lakes, oceans) as well as to some engineering applications. The detailed dynamics of such a system depend on the molecular diffusivities of heat, momentum, and solute as well as system parameters including the ratio of the two gradients to each other. Further important properties are the formation and merging of well-defined layers in the fluid which cannot be derived from linear stability analysis. Moreover, the physical processes operate on a vast range of length and time scales. This has made the case of semi-convection, where a mean temperature gradient destabilizes the stratification while at the same time the mean molecular gradient tends to stabilize it, a challenge to physical modelling and to numerical hydrodynamical simulation. During the MetStr{\"o}m project the simulation codes ANTARES and MITgcm have been extended such that they can be used for the simulations of such flows. We present a comparison of effective diffusivities derived from direct numerical simulations. For both stars and the oceanic regimes, the Nusselt numbers (scaled diffusivities) follow similar relationships. Semi-convection quickly becomes inefficient, because the formation of layers limits vertical mixing. In contrast to the complementary saltfingering, these layers tend to damp instabilities so that effective diffusivities of salinity (concentration) are up to two orders of magnitudes smaller than in the former case.}, language = {en} } @inproceedings{EgbersZaussinger, author = {Egbers, Christoph and Zaussinger, Florian}, title = {Simulation of geophysical fluid flows in spherical shells: The Geoflow experiments on ISS}, series = {Book of abstracts, School ISTROF 2016, Instabilities and Turbulence in Strato-Rotational Flows, July 11-13th, 2016, Le Havre}, booktitle = {Book of abstracts, School ISTROF 2016, Instabilities and Turbulence in Strato-Rotational Flows, July 11-13th, 2016, Le Havre}, language = {en} } @misc{GrimmStreleKupkaLoewBasellietal., author = {Grimm-Strele, Hannes and Kupka, Friedrich and L{\"o}w-Baselli, Bernhard and Mundprecht, Eva and Zaussinger, Florian and Schiansky, Peter}, title = {Realistic simulations of stellar surface convection with ANTARES: I. Boundary conditions and model relaxation}, series = {New Astronomy}, volume = {34}, journal = {New Astronomy}, issn = {1384-1076}, doi = {10.1016/j.newast.2013.11.005}, pages = {278 -- 293}, language = {en} } @inproceedings{ZaussingerEgbersKrebsetal., author = {Zaussinger, Florian and Egbers, Christoph and Krebs, Andreas and Travnikov, Vadim}, title = {New results of the spherical convection experiment Geoflow IIc}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @inproceedings{ZaussingerKrebsBreueretal., author = {Zaussinger, Florian and Krebs, Andreas and Breuer, Doris and Plesa, Ana-Catalina and Egbers, Christoph}, title = {Convection in the spherical gap with high viscosity contrasts}, series = {ICTW 19, Book of Abstracts, 19th International Couette-Taylor Workshop, June 24 - 26, 2015 Cottbus, Germany}, booktitle = {ICTW 19, Book of Abstracts, 19th International Couette-Taylor Workshop, June 24 - 26, 2015 Cottbus, Germany}, address = {Cottbus}, pages = {88 -- 89}, language = {en} } @inproceedings{ZaussingerChristlGorenzetal., author = {Zaussinger, Florian and Christl, Andreas and Gorenz, Paul and Neben, Matthias and Egbers, Christoph}, title = {An applied Couette-Taylor system as a simplified bearing model}, series = {Book of abstracts, ICTW 19, 19th International Couette-Taylor Workshop, June 24-26, 2015 Cottbus, Germany}, booktitle = {Book of abstracts, ICTW 19, 19th International Couette-Taylor Workshop, June 24-26, 2015 Cottbus, Germany}, publisher = {BTU}, address = {Cottbus}, pages = {170 -- 171}, language = {en} } @misc{ZaussingerKupkaEgbersetal., author = {Zaussinger, Florian and Kupka, Friedrich and Egbers, Christoph and Neben, Matthias and H{\"u}cker, S. and Bahr, C. and Schmitt, M.}, title = {Semi-convective layer formation}, series = {Journal of Physics: Conference Series}, volume = {837}, journal = {Journal of Physics: Conference Series}, number = {1}, doi = {10.1088/1742-6596/837/1/012012}, pages = {7}, language = {en} } @misc{TravnikovZaussingerBeltrameetal., author = {Travnikov, Vadim and Zaussinger, Florian and Beltrame, Philippe and Egbers, Christoph}, title = {Influence of the temperature-dependent viscosity on convective flow in the radial force field}, series = {Physical Review / E}, volume = {96}, journal = {Physical Review / E}, number = {2}, issn = {2470-0053}, doi = {10.1103/PhysRevE.96.023108}, pages = {023108}, language = {en} } @inproceedings{ZaussingerEgbersKrebs, author = {Zaussinger, Florian and Egbers, Christoph and Krebs, Andreas}, title = {The GeoFlow experiments on the ISS: Thermal convection under microgravity conditions}, series = {Joint Conference ISPS-7 and ELGRA-25 October, 2-6 2017, Juan-les-Pins, France, Abstract book}, booktitle = {Joint Conference ISPS-7 and ELGRA-25 October, 2-6 2017, Juan-les-Pins, France, Abstract book}, pages = {S. 30}, language = {en} } @techreport{UhligKirnerPreussetal., author = {Uhlig, Benedict and Kirner, Claus and Preuß, Ann-Christin and Graf, Johann and Neben, Matthias and Zaussinger, Florian}, title = {Kolbenring-{\"O}ltransport II : {\"O}ltransport durch die Kolbenringe}, publisher = {FVV, Forschungsvereinigung Verbrennungskraftmaschinen}, address = {Frankfurt am Main}, pages = {70}, abstract = {Ziele des Vorhabens sind die Verbesserung der Messtechnik f{\"u}r tribologische Untersuchungen in der Kolbengruppe aus dem Vorl{\"a}ufervorhaben Kolbenring-{\"O}ltransport I und die Untersuchung von verschiedenen Betriebsbedingungen und Komponenten hinsichtlich ihres Einflusses auf den {\"O}lhaushalt. Der Fokus liegt auf der verbesserten Aufl{\"o}sung der Schmierfilmdickenmessung und der Ringstoßlagen. Mit der erweiterten Kapillar- und Lichtleiterkonfiguration werden neue {\"O}ltransportvorg{\"a}nge entlang des Kolbenringpakets mittels Tracerinjektion und simultaner LiF-Messung beobachtet. Das methodische Vorgehen bei der optischen Analyse des Kapillarf{\"u}llungsgrades wird an einem Labor-Druckpr{\"u}fstand weiterentwickelt. Des Weiteren werden komplexe Simulationsmodelle erstellt, mit denen die Kolbensekund{\"a}r-bewegung, die Kolbenringbewegung, die Gasstr{\"o}mung im Ringpaket und der {\"O}ltransport im Ringpaket gekl{\"a}rt werden k{\"o}nnen. Die Kolbensekund{\"a}rbewegungsrechnung basiert auf einer FEM-Diskretisierung die aus CAD-Modellen s{\"a}mtlicher Bauteile abgeleitet ist. Die dreidimensionale Berechnung der Kolbenringbewegung erfolgt unter Ber{\"u}cksichtigung dynamisch wirkender Kr{\"a}fte aus der Bewegung, der Ringreibung, dem Gasdruck und den Zwischenring- dr{\"u}cken. Die Elastizit{\"a}t der Ringe wird ber{\"u}cksichtigt, so dass Biegung, Torsion und damit auch das Twisten abgebildet werden k{\"o}nnen. Nut- und Ringgeometrie sowie thermisch bedingte Verz{\"u}ge fließen ebenfalls in die Berechnung mit ein. Als Ergebnisgr{\"o}ßen stehen neben den Ringbewegungen und -lagen auch die Gasstr{\"o}mungen und -dr{\"u}cke, Schmierfilmh{\"o}hen und Verlustleistungen zur Verf{\"u}gung.}, language = {de} } @misc{ZaussingerHaunNebenetal., author = {Zaussinger, Florian and Haun, Peter and Neben, Matthias and Seelig, Torsten and Travnikov, Vadim and Egbers, Christoph and Yoshikawa, Harunori and Mutabazi, Innocent}, title = {Dielectrically driven convection in spherical gap geometry}, series = {Physical Review Fluids}, volume = {3}, journal = {Physical Review Fluids}, number = {9}, issn = {2469-990X}, doi = {10.1103/PhysRevFluids.3.093501}, pages = {093501-1 -- 093501-17}, language = {en} } @inproceedings{ZaussingerHaunMutabazietal., author = {Zaussinger, Florian and Haun, Peter and Mutabazi, Innocent and Egbers, Christoph}, title = {Dielectrically driven thermal convection}, series = {The 12th European Fluid Mechanics Conference, 9 September 2018 - 13 September 2018, Vienna, Austria}, booktitle = {The 12th European Fluid Mechanics Conference, 9 September 2018 - 13 September 2018, Vienna, Austria}, pages = {1}, language = {en} } @inproceedings{ZaussingerEgbersDriebeetal., author = {Zaussinger, Florian and Egbers, Christoph and Driebe, Thomas and Heintzmann, Pascal and Canfield, Peter and Meier, Martin and Travnikov, Vadim and Froitzheim, Andreas and Haun, Peter}, title = {ATMOFLOW - Simulating atmosphere flows on the international space station. Part II: Experiments and numerical simulations}, series = {69th International Astronautical Congress, 1 - 5 October 2018, Bremen, Germany}, booktitle = {69th International Astronautical Congress, 1 - 5 October 2018, Bremen, Germany}, pages = {1}, language = {en} } @inproceedings{ZaussingerEgbersHeintzmannetal., author = {Zaussinger, Florian and Egbers, Christoph and Heintzmann, Pascal and Canfield, Peter}, title = {ATMOFLOW - Simulating atmosphere flows on the international space station. Part I: Experiment and implementation concept}, series = {69th International Astronautical Congress, 1 - 5 October 2018, Bremen, Germany}, booktitle = {69th International Astronautical Congress, 1 - 5 October 2018, Bremen, Germany}, pages = {1}, language = {en} }