TY - CHAP A1 - Beltrame, Philippe A1 - Egbers, Christoph T1 - Heteroclinic cycles of type II in the (2,3) interaction in the GEOFLOW-experiment Y1 - 2004 ER - TY - CHAP A1 - Herzog, Nicoleta A1 - Gorenz, Paul A1 - Egbers, Christoph T1 - High pressurized CO2 release CFD calculations from onshore pipeline leakages T2 - European Geosciences Union (EGU), 10th General Assembly, Vienna, Austria, 07 – 12 April 2013 Y1 - 2013 UR - http://meetingorganizer.copernicus.org/EGU2013/EGU2013-1879.pdf N1 - EGU2013-1879 ER - TY - CHAP A1 - Zanoun, El-Sayed A1 - Durst, F. A1 - Egbers, Christoph T1 - High Reynolds Number Fully Developed Turbulent Pipe Flows Y1 - 2005 ER - TY - THES A1 - Maltese Meletti de Oliveira, Gabriel T1 - High-performance computing and laboratory experiments on strato-rotational instabilities Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-opus4-54408 CY - Cottbus ER - TY - GEN A1 - Borcia, Ion-Dan A1 - Borcia, Rodica A1 - Bestehorn, Michael A1 - Richter, Stefan A1 - Xu, Wenchao A1 - Harlander, Uwe T1 - Horizontal Faraday instability and parametric excitation in a circular channel T2 - GAMM 2019, 90th Annual Meeting of the International Assoociation of Applied Mathematics and Mechanics, February 18-22, 2019, Vienna, Austria Y1 - 2018 UR - https://jahrestagung.gamm-ev.de/images/2019/Photos/GAMM2019_BookofAbstracts.pdf SN - 978-3-903024-84-7 SP - 338 PB - TU Verlag CY - Wien ER - TY - CHAP A1 - Meier, Martin A1 - Ristau, R. A1 - Egbers, Christoph T1 - InertGasCondensation (IGC) - Process - Characterization in a microgravity environment Y1 - 2001 ER - TY - CHAP A1 - Randriamampianina, Anthony A1 - Harlander, Uwe A1 - Vincze, Miklos A1 - Seelig, Torsten A1 - Larcher, Thomas von A1 - Viazzo, Stephane T1 - Inertia gravity waves linked to baroclinic waves in a rotating, differentially heated annulus with an upper free surface T2 - ICTW 19 Book of Abstracts, 19th International Couette-Taylor Workshop, June 24 - 26, 2015 Cottbus, Germany Y1 - 2015 SP - 38 EP - 39 CY - Cottbus ER - TY - GEN A1 - Xu, Wenchao A1 - Harlander, Uwe T1 - Inertial mode interactions in a rotating tilted cylindrical annulus with free surface T2 - Physical Review Fluids Y1 - 2020 UR - https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.5.094801 U6 - https://doi.org/10.1103/PhysRevFluids.5.094801 SN - 2469-990X VL - 5 IS - 9 ER - TY - CHAP A1 - Hoff, Michael A1 - Harlander, Uwe A1 - Triana, Santiago Andrés A1 - Egbers, Christoph T1 - Inertial modes and their transition to turbulence in a differentially rotating spherical gap flow T2 - European Geosciences Union, General Assembly 2016, Vienna, Austria, 17-22. April 2016 Y1 - 2016 UR - http://meetingorganizer.copernicus.org/EGU2016/EGU2016-6990.pdf N1 - EGU2016-6990 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - CHAP A1 - Triana, Santiago Andrés A1 - Hoff, Michael A1 - Egbers, Christoph T1 - Inertial Modes driven by differential rotation in a spherical Couette configuration T2 - ICTW 19, Book of Abstracts, 19th International Couette-Taylor Workshop, June 24 - 26, 2015 Cottbus, Germany Y1 - 2015 SP - 84 EP - 85 CY - Cottbus ER - TY - GEN A1 - Klein, Marten A1 - Seelig, Torsten A1 - Kurgansky, Michael V. A1 - Ghasemi, Abouzar A1 - Borcia, Ion-Dan A1 - Will, Andreas A1 - Schaller, Eberhard A1 - Egbers, Christoph A1 - Harlander, Uwe T1 - Inertial wave excitation and focusing in a liquid bounded by a frustum and a cylinder T2 - Journal of Fluid Mechanics N2 - The mechanism of localized inertial wave excitation and its efficiency is investigated for an annular cavity rotating with Ω0 . Meridional symmetry is broken by replacing the inner cylinder with a truncated cone (frustum). Waves are excited by individual longitudinal libration of the walls. The geometry is non-separable and exhibits wave focusing and wave attractors. We investigated laboratory and numerical results for the Ekman number E ≈ 10−6. inclination α = 5.71◦ and libration amplitudes ε 0.2 within the inertial wave band 0 < ω < 2Ω0 . Under the assumption that the inertial waves do not essentially affect the boundary-layer structure, we use classical boundary-layer analysis to study oscillating Ekman layers over a librating wall that is at an angle α = 0 to the axis of rotation. The Ekman layer erupts at frequency ω = f∗, where f∗ ≡ 2Ω0 sin α is the effective Coriolis parameter in a plane tangential to the wall. For the selected inclination this eruption occurs for the forcing frequency ω/Ω0 = 0.2. For the librating lids eruption occurs at ω/Ω0 = 2. The study reveals that the frequency dependence of the total kinetic energy Kω of the excited wave field is strongly connected to the square of the Ekman pumping velocity wE (ω) that, in the linear limit, becomes singular when the boundary layer erupts. This explains the frequency dependence of non-resonantly excited waves. By the localization of the forcing, the two configurations investigated, (i) frustum libration and (ii) lids together with outer cylinder in libration, can be clearly distinguished by their response spectra. Good agreement was found for the spatial structure of low-order wave attractors and periodic orbits (both characterized by a small number of reflections) in the frequency windows predicted by geometric ray tracing. For ‘resonant’ frequencies a significantly increased total bulk energy was found, while the energy in the boundary layer remained nearly constant. Inertial wave energy enters the bulk flow via corner beams, which are parallel to the characteristics of the underlying Poincaré problem. Numerical simulations revealed a mismatch between the wall-parallel mass fluxes near the corners. This leads to boundary-layer eruption and the generation of inertial waves in the corners. KW - boundary-layer structure KW - geophysical and geological flows KW - waves in rotating fluids Y1 - 2014 U6 - https://doi.org/10.1017/jfm.2014.304 SN - 1750-6859 IS - vol. 751 SP - 255 EP - 297 ER - TY - CHAP A1 - Klein, Marten A1 - Ghasemi, Abouzar A1 - Harlander, Uwe A1 - Will, Andreas T1 - Inertial wave excitation and wave attractors in a librating annulus: DNS T2 - European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April – 02 May 2014 KW - boundary-layer structure KW - geophysical and geological flows KW - waves in rotating fluids KW - direct numerical simulations Y1 - 2014 N1 - EGU2014-15585 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - THES A1 - Seelig, Torsten T1 - Inertial wave propagation, focusing and mean flow excitation : theory and experiments Y1 - 2014 SN - 978-3-95404-793-2 SN - 978-3-7369-4793-1 PB - Cuvillier CY - Göttingen ER - TY - CHAP A1 - Seelig, Torsten A1 - Borcia, Ion-Dan A1 - Klein, Marten A1 - Ghasemi, Abouzar A1 - Will, Andreas A1 - Egbers, Christoph A1 - Schaller, Eberhard A1 - Harlander, Uwe T1 - Inertial waves and wave attractors in a rotating annulus with inner or outer cylinder libration T2 - European Geosciences Union (EGU), 10th General Assembly, Vienna, Austria, 07 – 12 April 2013 Y1 - 2013 UR - http://meetingorganizer.copernicus.org/EGU2013/EGU2013-7602.pdf N1 - EGU2013-7602 ER - TY - CHAP A1 - Klein, Marten A1 - Borcia, Ion-Dan A1 - Egbers, Christoph A1 - Ghasemi, Abouzar A1 - Harlander, Uwe A1 - Kurgansky, Michael V. A1 - Schaller, Eberhard A1 - Seelig, Torsten A1 - Will, Andreas T1 - Inertial Waves and Wave Excitation Mechanisms in Annular Cavities: Simulations, Experiments and Theory T2 - European Turbulence Conference ETC14, Lyon, 2013 KW - boundary-layer structure KW - geophysical and geological flows KW - waves in rotating fluids Y1 - 2013 UR - http://etc14.ens-lyon.fr/etc-14-proceedings/accepted-talks ER - TY - GEN A1 - Borcia, Ion-Dan A1 - Harlander, Uwe T1 - Inertial waves in a rotating annulus with inclined inner cylinder: comparing the spectrum of wave attractor frequency bands and the eigenspectrum in the limit of zero inclination T2 - Theoretical and Computational Fluid Dynamics Y1 - 2013 U6 - https://doi.org/10.1007/s00162-012-0278-6 SN - 1432-2250 VL - 27 IS - 3-4 SP - 397 EP - 413 ER - TY - CHAP A1 - Koch, Sandy A1 - Harlander, Uwe A1 - Hollerbach, Rainer A1 - Egbers, Christoph T1 - Inertial waves in a rotating spherical shell: Comparison between numerical simulations and laboratory experiments T2 - European Geosciences Union (EGU), 9th General Assembly, Vienna, Austria, 22-27 April Y1 - 2012 UR - http://meetingorganizer.copernicus.org/EGU2012/EGU2012-7342.pdf N1 - EGU2012-7342 ER - TY - CHAP A1 - Koch, Sandy A1 - Harlander, Uwe A1 - Hollerbach, Rainer A1 - Egbers, Christoph T1 - Inertial waves in a spherical shell induced by librations of the inner sphere: experimental and numerical results T2 - European Geosciences Union (EGU), 10th General Assembly, Vienna, Austria, 07 – 12 April 2013 Y1 - 2013 UR - http://meetingorganizer.copernicus.org/EGU2013/EGU2013-4637.pdf N1 - EGU2013-4637 ER - TY - GEN A1 - Koch, Sandy A1 - Harlander, Uwe A1 - Egbers, Christoph A1 - Hollerbach, Rainer T1 - Inertial waves in a spherical shell induced by librations of the inner sphere: experimental and numerical results T2 - Fluid Dynamics Research Y1 - 2013 U6 - https://doi.org/10.1088/0169-5983/45/3/035504 SN - 0169-5983 VL - 45 IS - 3 SP - 035504 ER - TY - CHAP A1 - Seelig, Torsten A1 - Harlander, Uwe A1 - Borcia, Ion-Dan A1 - Scurtu, Nicoleta A1 - Egbers, Christoph A1 - Klein, Marten A1 - Ghasemi, Abouzar A1 - Will, Andreas A1 - Schaller, Eberhard T1 - Inertial waves in rotating cylindrical annulus: theory, experiment and simulations T2 - Book of abstracts, 9th European Fluid Mechanics Conference (EFMC), 9-13 September, Rome, Italy Y1 - 2012 UR - http://www.efmc9.eu/absbook/index.html ER - TY - CHAP A1 - Borcia, Ion-Dan A1 - Seelig, Torsten A1 - Harlander, Uwe A1 - Egbers, Christoph T1 - Inertial waves in rotating cylindrical geometry: mean flow interactions and attractors Y1 - 2011 ER - TY - CHAP A1 - Borcia, Ion-Dan A1 - Harlander, Uwe T1 - Inertial waves inside a liquid confined between two rotating coaxial cylinders: the case of small Ekman number Y1 - 2011 ER - TY - CHAP A1 - Yousry, Mohamed A1 - Merbold, Sebastian A1 - Egbers, Christoph ED - Delgado, Antonio T1 - Influence of convex structured surfaces on turbulent channel flow at different channel heights T2 - Experimentelle Strömungsmechanik : 27. Fachtagung 3.-5. September 2019 Erlangen Y1 - 2019 SN - 978-3-9816764-6-4 SP - 5.1 EP - 5.9 PB - Deutsche Gesellschaft für Laser-Anemometrie - German Association for Laser Anemometry GALA e.V. CY - Karlsruhe ER - TY - GEN A1 - Travnikov, Vadim A1 - Zaussinger, Florian A1 - Haun, Peter A1 - Egbers, Christoph T1 - Influence of dielectrical heating on convective flow in a radial force field T2 - Physical Review E Y1 - 2020 U6 - https://doi.org/10.1103/PhysRevE.101.053106 SN - 2470-0053 SN - 2470-0045 VL - 101 IS - 5 ER - TY - GEN A1 - Zaussinger, Florian A1 - Egbers, Christoph A1 - Travnikov, Vadim A1 - Haun, Peter T1 - Influence of internal heating on convection in the rotating spherical gap T2 - 17th European Turbulence Conference, ETC 2019, September 3 - 6, 2019, Torino, Italy Y1 - 2019 UR - http://www.symposium.it/files/eventi/84/etc-2019-561.pdf CY - Turin ER - TY - CHAP A1 - Hasanuzzaman, Gazi A1 - Merbold, Sebastian A1 - Motuz, Vasyl A1 - Egbers, Christoph T1 - Influence of micro-blowing technique on skin friction of boundary layer flows T2 - 11th European Fluid Mechanics Conference, Sept. 12-16, 2016, Sevilla, Spain Y1 - 2016 UR - http://www.efmc11.org/download/com/com_0650_3H6SHY.pdf ER - TY - CHAP A1 - Martinez-Arias, Borja A1 - Peixinho, Jorge A1 - Froitzheim, Andreas A1 - Merbold, Sebastian A1 - Egbers, Christoph A1 - Mutabazi, Innocent T1 - Influence of the radius ratio on the torque in turbulent Taylor-Couette flow T2 - ICTW 19, Book of Abstracts, 19th International Couette-Taylor Workshop, June 24 - 26, 2015 Cottbus, Germany Y1 - 2015 SP - 30 EP - 31 CY - Cottbus ER - TY - GEN A1 - Travnikov, Vadim A1 - Zaussinger, Florian A1 - Beltrame, Philippe A1 - Egbers, Christoph T1 - Influence of the temperature-dependent viscosity on convective flow in the radial force field T2 - Physical Review / E Y1 - 2017 U6 - https://doi.org/10.1103/PhysRevE.96.023108 SN - 2470-0053 VL - 96 IS - 2 SP - 023108 ER - TY - GEN A1 - Scurtu, Nicoleta A1 - Bänsch, E. T1 - Influence of the Weissenberg number on the stability of Oldroyd kind fluids Y1 - 2010 ER - TY - CHAP A1 - Deters, T. A1 - Guillerm, R. A1 - Egbers, Christoph A1 - Zanoun, El-Sayed T1 - Influence of thermal convection in Taylor-Couette flows Y1 - 2007 ER - TY - JOUR A1 - Deters, T. A1 - Egbers, Christoph A1 - Zanoun, El-Sayed A1 - Guillerm, R. T1 - Influence of thermal convection in Taylor-Couette flows Y1 - 2008 ER - TY - CHAP A1 - Yousry, Mohamed A1 - Shahirpour, Amir A1 - Merbold, Sebastian A1 - Egbers, Christoph ED - Egbers, Christoph T1 - Influence on flow behaviour inside a rectangular channel by patterned surface T2 - Experimentelle Strömungsmechanik, 24. Fachtagung 6.-8. September 2016 Cottbus Y1 - 2016 SN - 978-3-9816764-2-6 SP - S. 26 PB - German Association for Laser Anemometry GALA e.V. CY - Karlsruhe ER - TY - CHAP A1 - Egbers, Christoph T1 - Instabilities and bifurcation scenarios in rotating fluids Y1 - 2004 ER - TY - GEN A1 - Schön, Franz-Theo A1 - Bestehorn, Michael T1 - Instabilities and pattern formation in viscoelastic fluids T2 - The European Physical Journal Special Topics Y1 - 2023 UR - https://link.springer.com/article/10.1140/epjs/s11734-023-00792-x U6 - https://doi.org/10.1140/epjs/s11734-023-00792-x SN - 1951-6401 VL - Vol. 232 IS - 4 SP - 375 EP - 383 ER - TY - GEN A1 - Larcher, Thomas von A1 - Viazzo, Stephane A1 - Harlander, Uwe A1 - Vincze, Miklos T1 - Instabilities and small-scale waves within the Stewartson layers of a thermally driven rotating annulus T2 - Journal of Fluid Mechanics Y1 - 2018 U6 - https://doi.org/10.1017/jfm.2018.10 SN - 1750-6859 IS - vol. 841 SP - 380 EP - 407 ER - TY - CHAP A1 - More, Tamar A1 - Futterer, Birgit A1 - Hollerbach, Rainer A1 - Egbers, Christoph T1 - Instabilities of the Stewartson Layer II : An Experimental/Numerical Comparison T2 - Nonlinear dynamics in fluids Y1 - 2003 SN - 84-95999-28-5 SP - 186 EP - 189 PB - Cimne CY - Barcelona ET - 1. edition ER - TY - JOUR A1 - Hollerbach, Rainer T1 - Instabilities of the Stewartson Layer, part 1. The dependence on the sign of Ro Y1 - 2003 ER - TY - JOUR A1 - Hollerbach, Rainer A1 - Egbers, Christoph A1 - Futterer, Birgit A1 - More, Tamar T1 - Instabilities of the Stewartson layer, part 2. Supercritical mode transitions Y1 - 2004 ER - TY - CHAP A1 - Smieszek, Marlene A1 - Crumeyrolle, Olivier A1 - Egbers, Christoph A1 - Mutabazi, Innocent T1 - Instabilities with polyacrylamide solution in small and large aspect ratio Taylor-Couette systems Y1 - 2007 ER - TY - JOUR A1 - Smieszek, Marlene A1 - Crumeyrolle, Olivier A1 - Egbers, Christoph A1 - Mutabazi, Innocent T1 - Instabilities with polyacrylamide solution in small and large aspect ratio Taylor-Couette systems Y1 - 2007 ER - TY - JOUR A1 - Smieszek, Marlene A1 - Crumeyrolle, Olivier A1 - Mutabazi, Innocent A1 - Egbers, Christoph T1 - Instabilities with polyacrylamide solution in small and large aspect ratios Taylor-Couette systems Y1 - 2008 ER - TY - GEN A1 - Le Gal, Patrice A1 - Harlander, Uwe A1 - Borcia, Ion-Dan A1 - Le Dizès, Stéphane A1 - Chen, J. A1 - Favier, Benjamin T1 - Instability of vertically stratified horizontal plane Poiseuille flow T2 - Journal of Fluid Mechanics Y1 - 2021 U6 - https://doi.org/10.1017/jfm.2020.917 SN - 1469-7645 SN - 0022-1120 VL - 907 IS - R1 SP - 1 EP - 14 ER - TY - CHAP A1 - Zanoun, El-Sayed A1 - Egbers, Christoph A1 - Öngüner, Emir T1 - Integral Flow parapeters for evaluating the law of the wall in pipe and channel facilities T2 - 11th European Fluid Mechanics Conference, Sept. 12-16, 2016, Sevilla, Spain Y1 - 2016 UR - https://www-docs.b-tu.de/fg-aerodynamik-stroemungslehre/public/PDF/Pubs/efmc11/com_0003_VPZ7VS.pdf ER - TY - CHAP A1 - Hoff, Michael A1 - Harlander, Uwe A1 - Egbers, Christoph A1 - Triana, Santiago Andrés T1 - Interacting inertial modes and their instability in a differentially rotating spherical gap flow T2 - Book of abstracts, 31st IUGG Conference on Mathematical Geophysics 6 - 10 June 2016 Paris, France Y1 - 2016 UR - https://cmg2016.sciencesconf.org/ SP - S. 37 ER - TY - CHAP A1 - Hoff, Michael A1 - Harlander, Uwe A1 - Egbers, Christoph A1 - Triana, Santiago Andrés ED - Egbers, Christoph T1 - Interacting inertial modes in a differentially rotating spherical gap flow experiment T2 - Experimentelle Strömungsmechanik, 24. Fachtagung 6.-8. September 2016 Cottbus Y1 - 2016 SN - 978-3-9816764-2-6 SP - S. 12 PB - German Association for Laser Anemometry GALA e.V. CY - Karlsruhe ER - TY - GEN A1 - Harlander, Uwe A1 - Wang, Yongtai A1 - Alexandrov, Kiril A1 - Seelig, Torsten A1 - Egbers, Christoph T1 - Intercomparison of numerical models simulating rotating annulus flows Y1 - 2011 ER - TY - CHAP A1 - Gorenz, Paul A1 - Herzog, Nicoleta A1 - Egbers, Christoph T1 - Investigation of CO2 release pressures in pipeline cracks T2 - European Geosciences Union (EGU), 10th General Assembly, Vienna, Austria, 07 – 12 April 2013 Y1 - 2013 UR - http://meetingorganizer.copernicus.org/EGU2013/EGU2013-5816-1.pdf N1 - EGU2013-5816 ER - TY - GEN A1 - Gorenz, Paul A1 - Herzog, Nicoleta A1 - Egbers, Christoph T1 - Investigation of CO2 release pressures in pipeline cracks T2 - Energy Procedia Y1 - 2013 SN - 1876-6102 VL - 40 SP - 285 EP - 293 ER - TY - CHAP A1 - Butt, Usman A1 - Jehring, Lothar A1 - Egbers, Christoph T1 - Investigation of flow over bluff bodies with patterned surface using Laser-Doppler Anemometry T2 - Lasermethoden in der Strömungsmesstechnik, 20. Fachtagung, 04. - 06. September 2012, Rostock Y1 - 2012 SN - 978-3-9805613-8-9 PB - GALA CY - Karlsruhe ER - TY - THES A1 - König, Franziska T1 - Investigation of High Reynolds Number Pipe Flow Y1 - 2015 SN - 978-3-73699-049-4 PB - Cuvillier CY - Göttingen ER - TY - GEN A1 - Richter, Stefan A1 - Zanoun, El-Sayed A1 - Egbers, Christoph T1 - Investigation of Large Scale Motion Interaction with the Near‐Wall Turbulence T2 - Proceedings in applied mathematics and mechanics : PAMM Y1 - 2021 U6 - https://doi.org/10.1002/pamm.202000331 SN - 1617-7061 VL - 20 IS - 1 ER - TY - GEN A1 - Egbers, Christoph A1 - Gellert, Marcus A1 - Harlander, Uwe A1 - Wang, Yongtai A1 - Rüdiger, Günther T1 - Investigation of Stratorotational Instability (SRI) in Taylor-Couette flows with axial temperature gradient Y1 - 2011 ER - TY - CHAP A1 - Meier, Martin A1 - Jongmanns, Marcel A1 - Egbers, Christoph ED - Egbers, Christoph T1 - Investigations on thermal electro-hydrodynamic convection in a cylindrical gap T2 - Experimentelle Strömungsmechanik, 24. Fachtagung 6.-8. September 2016 Cottbus Y1 - 2016 SN - 978-3-9816764-2-6 SP - S. 39 PB - German Association for Laser Anemometry GALA e.V. CY - Karlsruhe ER - TY - CHAP A1 - Seelig, Torsten A1 - Harlander, Uwe A1 - Faulwetter, Robin A1 - Egbers, Christoph T1 - Irregular and singular vector growth in the differentially heated rotating annulus Y1 - 2011 UR - http://www.mpia-hd.mpg.de/Baroclinic2011/T12.php ER - TY - CHAP A1 - Seelig, Torsten A1 - Harlander, Uwe A1 - Faulwetter, Robin A1 - Egbers, Christoph T1 - Irregular and singular vector growth in the differentially heated rotating annulus Y1 - 2011 ER - TY - GEN A1 - Seelig, Torsten A1 - Harlander, Uwe A1 - Faulwetter, Robin A1 - Egbers, Christoph T1 - Irregularity and singular vector growth of the differentially heated rotating annulus flow Y1 - 2011 ER - TY - GEN A1 - Rodda, Costanza A1 - Harlander, Uwe A1 - Vincze, Miklos T1 - Jet stream variability in a polar warming scenario – a laboratory perspective T2 - Weather and Climate Dynamics Y1 - 2022 UR - https://wcd.copernicus.org/articles/3/937/2022/ U6 - https://doi.org/10.5194/wcd-3-937-2022 SN - 2698-4016 VL - 3 IS - 3 SP - 937 EP - 950 ER - TY - RPRT A1 - Uhlig, Benedict A1 - Kirner, Claus A1 - Preuß, Ann-Christin A1 - Graf, Johann A1 - Neben, Matthias A1 - Zaussinger, Florian T1 - Kolbenring-Öltransport II : Öltransport durch die Kolbenringe N2 - Ziele des Vorhabens sind die Verbesserung der Messtechnik für tribologische Untersuchungen in der Kolbengruppe aus dem Vorläufervorhaben Kolbenring-Öltransport I und die Untersuchung von verschiedenen Betriebsbedingungen und Komponenten hinsichtlich ihres Einflusses auf den Ölhaushalt. Der Fokus liegt auf der verbesserten Auflösung der Schmierfilmdickenmessung und der Ringstoßlagen. Mit der erweiterten Kapillar- und Lichtleiterkonfiguration werden neue Öltransportvorgänge entlang des Kolbenringpakets mittels Tracerinjektion und simultaner LiF-Messung beobachtet. Das methodische Vorgehen bei der optischen Analyse des Kapillarfüllungsgrades wird an einem Labor-Druckprüfstand weiterentwickelt. Des Weiteren werden komplexe Simulationsmodelle erstellt, mit denen die Kolbensekundär-bewegung, die Kolbenringbewegung, die Gasströmung im Ringpaket und der Öltransport im Ringpaket geklärt werden können. Die Kolbensekundärbewegungsrechnung basiert auf einer FEM-Diskretisierung die aus CAD-Modellen sämtlicher Bauteile abgeleitet ist. Die dreidimensionale Berechnung der Kolbenringbewegung erfolgt unter Berücksichtigung dynamisch wirkender Kräfte aus der Bewegung, der Ringreibung, dem Gasdruck und den Zwischenring- drücken. Die Elastizität der Ringe wird berücksichtigt, so dass Biegung, Torsion und damit auch das Twisten abgebildet werden können. Nut- und Ringgeometrie sowie thermisch bedingte Verzüge fließen ebenfalls in die Berechnung mit ein. Als Ergebnisgrößen stehen neben den Ringbewegungen und -lagen auch die Gasströmungen und -drücke, Schmierfilmhöhen und Verlustleistungen zur Verfügung. Y1 - 2017 PB - FVV, Forschungsvereinigung Verbrennungskraftmaschinen CY - Frankfurt am Main ER - TY - CHAP A1 - Koch, Sandy A1 - Harlander, Uwe A1 - Hollerbach, Rainer A1 - Egbers, Christoph T1 - Laboratory experiment and numerical simulations of inertial wave interactions in a rotating spherical shell Y1 - 2011 ER - TY - GEN A1 - Koch, Sandy A1 - Harlander, Uwe A1 - Hollerbach, Rainer A1 - Egbers, Christoph T1 - Laboratory experiment of inertial wave-interactions in a rotating spherical shell Y1 - 2011 ER - TY - GEN A1 - Koch, Sandy A1 - Harlander, Uwe A1 - Hollerbach, Rainer A1 - Egbers, Christoph T1 - Laboratory experiments and numerical simulations of inertial wave-interactions in a rotating spherical shell Y1 - 2011 ER - TY - THES A1 - Dahley, Sandy T1 - Laboratory experiments and numerical simulations of inertial waves in a rotating spherical shell Y1 - 2016 SN - 978-3-73699-198-9 PB - Cuvillier Verlag CY - Göttingen ER - TY - GEN A1 - Koch, Sandy A1 - Harlander, Uwe A1 - Hollerbach, Rainer A1 - Egbers, Christoph T1 - Laboratory experiments of inertial waves in containers rotating with time modulation Y1 - 2011 ER - TY - CHAP A1 - Shahirpour, Amir A1 - Sesterhenn, Jörn A1 - Egbers, Christoph T1 - Lagrangian Dynamic Mode Decomposition to capture Linearized Coherent Structures T2 - Fachtagung der Gesellschaft für Angewandte Mathematik und Mechanik (GAMM), Braunschweig, 7.-11. März 2016 Y1 - 2016 UR - https://arxiv.org/pdf/1603.02539v1.pdf ER - TY - GEN A1 - Durst, Franz A1 - Zanoun, El-Sayed T1 - Laminar pipe flow instability : a theoretical-experimental perspective T2 - Fluids N2 - This paper revisits the theoretically predicted inherent stability of fully developed laminar pipe flow, which remains unconfirmed by experimental evidence. A recently developed theory of pipe-flow stability/instability addresses the gap between experimental observations and classical theoretical predictions by accounting for a parallel secondary flow through the pipe’s roughness layer that accompanies the main stream. This secondary flow alters the near-wall velocity profile in the rough-wall region, creating an inflection point that promotes shear-driven instabilities and triggers the laminar-to-turbulent transition. A stability factor 𝑆=𝐷𝑐/𝐷 is introduced, where D is the nominal pipe diameter and 𝐷𝑐 refers to the critical pipe diameter. The pipe flow remains laminar and stable for 𝑆>1.0, and becomes unstable for 𝑆<1. Various experimental findings are theoretically derived, and the laminar-to-turbulent transition is identified at 𝑆=1.0. Particular attention is paid to the dependence of flow transition on both pipe diameter and pipe length. Rather than relying on a critical Reynolds number 𝑅𝑒𝑐, this study proposes the critical pipe diameter 𝐷𝑐 as the key parameter governing the laminar pipe flow instability, where 𝑅𝑒𝑐 refers here to the condition-dependent threshold at which laminar pipe flow becomes unstable and transition to turbulence occurs. The present analysis further suggests that instability arises only if the pipe length L exceeds a critical threshold 𝐿𝑐, that is, 𝐿>𝐿𝑐. The theoretical treatment presented provides deeper physical insights into the onset of laminar pipe flow instability including the phenomenon of reverse transition. It also distinguishes between natural and forced flow transitions, providing a refined understanding of the transition process. Finally, suggestions for future experimental work are made to further validate or challenge this new theoretical perspective on pipe flow instability. Y1 - 2025 U6 - https://doi.org/10.3390/fluids10080216 SN - 2311-5521 VL - 10 IS - 8 SP - 1 EP - 21 PB - MDPI CY - Basel ER - TY - CHAP A1 - Froitzheim, Andreas A1 - Merbold, Sebastian A1 - Egbers, Christoph A1 - Ezeta, Rodrigo A1 - Lohse, D. A1 - Sun, C. T1 - Large scale vortices in the Taylor-Couette flow T2 - The 12th European Fluid Mechanics Conference, 9 September 2018 – 13 September 2018, Vienna, Austria Y1 - 2018 UR - http://info.tuwien.ac.at/efmc12/EFMC12_program_v3.2.pdf ER - TY - GEN A1 - Buchwald, Tom A1 - Hasanuzzaman, Gazi A1 - Merbold, Sebastian A1 - Schanz, Daniel A1 - Egbers, Christoph A1 - Schröder, Andreas T1 - Large-scale flow field and aerosol particle transport investigations in a classroom using 2D-Shake-The-Box Lagrangian Particle Tracking T2 - Heliyon Y1 - 2023 U6 - https://doi.org/10.1016/j.heliyon.2023.e22826 SN - 2405-8440 VL - 9 IS - 12 ER - TY - CHAP A1 - Kito, Mizuki A1 - Zanoun, El-Sayed A1 - Jehring, Lothar A1 - Egbers, Christoph T1 - Laser-Doppler Anemometry in Turbulent Boundary Layers Induced by Different Tripping Devices Compared with Recent Theories Y1 - 2006 ER - TY - CHAP A1 - Stücke, Peter A1 - Nobis, Matthias A1 - Schmidt, M. A1 - Scurtu, Nicoleta A1 - Egbers, Christoph T1 - Laseroptische und numerische Untersuchung von Taylorwirbeln Y1 - 2010 ER - TY - CHAP A1 - Yousry, Mohamed A1 - Merbold, Sebastian A1 - Egbers, Christoph ED - Ruck, Bodo T1 - LDA measurements over hexagonal structured cavity inside turbulent channel flow T2 - Experimentelle Strömungsmechanik, 25. Fachtagung, 5.-7. September 2017, Karlsruhe Y1 - 2017 SN - 978-3-9816764-3-3 SP - S. 22 PB - Deutsche Gesellschaft für Laser-Anemometrie GALA e.V. CY - Karlsruhe ER - TY - CHAP A1 - Stücke, Peter A1 - Lehmann, B. A1 - Scurtu, Nicoleta A1 - Egbers, Christoph T1 - LDA-Messung in Zylinderspaltströmungen bei engen Spaltweiten Y1 - 2006 ER - TY - CHAP A1 - Larcher, Thomas von A1 - Beyer, Wolfgang A1 - Egbers, Christoph T1 - LDA-Messungen zur Untersuchung barokliner Instabilitäten Y1 - 2002 ER - TY - CHAP A1 - Larcher, Thomas von A1 - Egbers, Christoph T1 - LDA-Messungen zur Untersuchung barokliner Instabilitäten, Lasermethoden in der Strömungsmesstechnik Y1 - 2002 ER - TY - CHAP A1 - Sitte, B. A1 - Larcher, Thomas von A1 - Egbers, Christoph T1 - LDV-measurements on higher order dynamicsof baroclinic waves Y1 - 2001 ER - TY - GEN A1 - Travnikov, Vadim A1 - Egbers, Christoph T1 - Linear stability analysis of the convective flow in a spherical gap with rotating inner surface T2 - International Journal of Heat and Mass Transfer Y1 - 2020 UR - https://www.sciencedirect.com/science/article/pii/S0017931019315716?via%3Dihub U6 - https://doi.org/10.1016/j.ijheatmasstransfer.2019.119052 SN - 0017-9310 SN - 1879-2189 VL - 148 ER - TY - GEN A1 - Labarbe, Joris A1 - Le Gal, Patrice A1 - Harlander, Uwe A1 - Le Dizès, Stéphane A1 - Favier, Benjamin T1 - Localized layers of turbulence in stratified horizontally sheared Poiseuille flow T2 - Fluid Dynamics Y1 - 2023 UR - https://arxiv.org/abs/2207.09131 ER - TY - GEN A1 - Früh, Wolf-Gerrit A1 - Szabo, Peter A1 - Egbers, Christoph A1 - Harlander, Uwe T1 - Locating sources of variability in the transition to Structural Vacillation in the baroclinic annulus T2 - EGU General Assembly 2020, Online | 4–8 May 2020 Y1 - 2020 UR - https://ui.adsabs.harvard.edu/abs/2020EGUGA..22.7262F/abstract U6 - https://doi.org/10.5194/egusphere-egu2020-7262 ER - TY - GEN A1 - Harlander, Uwe A1 - Ridderinkhof, H. A1 - Schouten, M. W. A1 - Ruijter, W. P. M. de T1 - Long term observations of transport eddies, and Rossby waves in the Mozambique Channel Y1 - 2009 U6 - https://doi.org/10.1029/2008JC004846 ER - TY - CHAP A1 - Scurtu, Nicoleta A1 - Gorenz, Paul A1 - Egbers, Christoph T1 - Magnetorotational-type instability in Couette-Taylor flows of viscoelastic polymeric liquids Y1 - 2011 ER - TY - GEN A1 - Borcia, I. D. A1 - Bestehorn, M. A1 - Borcia, R. A1 - Schön, F.-T. A1 - Harlander, U. A1 - Richter, S. T1 - Mean flow generated by asymmetric periodic excitation in an annular channel T2 - The European Physical Journal Special Topics Y1 - 2024 U6 - https://doi.org/10.1140/epjs/s11734-024-01181-8 VL - 233 (2024) SP - 1665 EP - 1672 PB - Springer ER - TY - CHAP A1 - Klein, Marten A1 - Ghasemi, Abouzar A1 - Seelig, Torsten A1 - Borcia, Ion-Dan A1 - Harlander, Uwe A1 - Will, Andreas T1 - Mean flow generation and inertial wave attractors in a librating annulus: DNS and theory T2 - European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015 KW - boundary-layer structure KW - direct numerical simulation KW - instability KW - waves in rotating fluids Y1 - 2015 UR - http://meetingorganizer.copernicus.org/EGU2015/EGU2015-15640-1.pdf N1 - EGU2015-15640-1 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - GEN A1 - Ghasemi, Abouzar A1 - Klein, Marten A1 - Will, Andreas A1 - Harlander, Uwe T1 - Mean flow generation by an intermittently unstable boundary layer over a sloping wall T2 - Journal of Fluid Mechanics Y1 - 2018 U6 - https://doi.org/10.1017/jfm.2018.552 SN - 1750-6859 IS - vol. 853 SP - 111 EP - 149 ER - TY - GEN A1 - Ghasemi, Abouzar A1 - Klein, Marten A1 - Harlander, Uwe A1 - Kurgansky, Michael V. A1 - Schaller, Eberhard A1 - Will, Andreas T1 - Mean flow generation by Görtler vortices in a rotating annulus with librating side walls T2 - Physics of Fluids N2 - Time periodic variation of the rotation rate of an annulus induces in supercritical regime an unstable Stokes boundary layer over the cylinder side walls, generating Görtler vortices in a portion of a libration cycle as a discrete event. Numerical results show that these vortices propagate into the fluid bulk and generate an azimuthal mean flow. Direct numerical simulations of the fluid flow in an annular container with librating outer (inner) cylinder side wall and Reynolds-averaged Navier–Stokes (RANS) equations as diagnostic equations are used to investigate generation mechanism of the retrograde (prograde) azimuthal mean flow in the bulk. First, we explain, phenomenologically, how absolute angular momentum of the bulk flow is mixed and changed due to the propagation of the Görtler vortices, causing a new vortex of basin size. Then we investigate the RANS equations for intermediate time scale of the development of the Görtler vortices and for long time scale of the order of several libration periods. The former exhibits sign selection of the azimuthal mean flow. Investigating the latter, we predict that the azimuthal mean flow is proportional to the libration amplitude squared and to the inverse square root of the Ekman number and libration frequency and then confirms this using the numerical data. Additionally, presence of an upscale cascade of energy is shown, using the kinetic energy budget of fluctuating flow. KW - Direct Numerical Simulation KW - Fluid Mechanics KW - Mean Flow KW - Rotation KW - Cylinder KW - Centrifugal KW - Instability KW - Mechanism KW - Vortex Y1 - 2016 U6 - https://doi.org/10.1063/1.4948406 VL - 28 IS - 056603 SP - 1 EP - 23 ER - TY - CHAP A1 - Seelig, Torsten A1 - Ghasemi, Abouzar A1 - Kurgansky, Michael V. A1 - Klein, Marten A1 - Will, Andreas A1 - Harlander, Uwe T1 - Mean flow generation due to longitudinal librations of sidewalls of a rotating annulus T2 - 15th European turbulence conference (ETC), Delft, The Netherlands (2015) Y1 - 2015 UR - http://www.etc15.nl/proceedings/proceedings/documents/175.pdf ER - TY - GEN A1 - Kurgansky, Michael V. A1 - Seelig, Torsten A1 - Klein, Marten A1 - Will, Andreas A1 - Harlander, Uwe T1 - Mean flow generation due to longitudinal librations of sidewalls of a rotating annulus T2 - Geophysical & Astrophysical Fluid Dynamics N2 - Laboratory experiments with a rotating cylindrical annulus arereported that reveal a prograde jet, which is adjacent to a (longitu-dinally) librating inner straight cylindrical wall. Here, wall libration isrealised as a time-harmonic modulation of the inner cylinder’s rota-tion rate. The outer cylindrical wall and bottom and top lids rotatewith constant angular velocity. The main purpose of our study is tocontribute to a qualitative and quantitative understanding of non-linearities that are present in oscillating, but centrifugally stable,vertical boundary layers frequently encountered in rotating wall-bounded flows. We consider a problem that is in a sense comple-mentary to that of previous works that focused on oscillating Ekmanlayers but neglected the vertical Stokes−Stewartson layers. A sim-ple analytical model is proposed that is able to predict the magni-tude and spatial structure of the emerging prograde near-wall jet interms of nonlinearity inherent in the inner cylinder’s boundary layerdynamics. KW - boundary layer structure KW - geophysical and geological flows KW - longitudinal libration Y1 - 2020 U6 - https://doi.org/10.1080/03091929.2019.1692829 SN - 1029-0419 VL - 114 IS - 6 SP - 762 ER - TY - GEN A1 - Xu, Wenchao A1 - Harlander, Uwe T1 - Mean flow generation in rotating annulus with stochastic methods T2 - 17th European Turbulence Conference, ETC 2019, September 3 - 6, 2019, Torino, Italy Y1 - 2019 UR - http://www.symposium.it/files/eventi/84/etc-2019-561.pdf CY - Turin ER - TY - CHAP A1 - Zanoun, El-Sayed A1 - Durst, F. A1 - Egbers, Christoph T1 - Mean Flow Properties in Smooth Pipe Flow Experiment Y1 - 2006 ER - TY - GEN A1 - Schön, Franz-Theo A1 - Harlander, Uwe A1 - Borcia, Ion Dan A1 - Borcia, Rodica A1 - Bestehorn, Michael T1 - Mean fluid transport in an oscillating circular channel with asymmetric forcing T2 - Water waves : an interdisciplinary journal N2 - We investigate surface waves in an oscillating circular channel with local topography. The focus is on spatially or temporally breaking this dynamic system’s symmetry. Asymmetrical wave dynamics and a mean flux excitation are detected to varying degrees, depending on the two input parameters, fluid depth and the tank’s oscillation frequency. The fluid resonates around multiples of the fundamental eigenfrequency of the channel. The development of solitary wave-trains (undular bores) is observed in these resonance bands. A particle image velocimetry system measures the velocity field in the vertical plane of the free surface flow. Moreover, we are using 17 evenly distributed ultrasonic sensors to measure the surface displacement. This makes it possible to find out how strongly the mean flux depends on the resonance frequencies and to study the influence of the surface waves on the symmetry breaking. A numerical long-wave model helps to isolate the various factors influencing the mean flux. Y1 - 2025 U6 - https://doi.org/10.1007/s42286-025-00121-w SN - 2523-3688 VL - 2025 SP - 1 EP - 21 PB - Birkhäuser, part of Springer Nature CY - Basel ER - TY - GEN A1 - Uhlig, Benedict A1 - Preuß, Ann-Christin A1 - Graf, Johann A1 - Neben, Matthias T1 - Measurement and Simulation of the Oil Supply at the Piston Assembly T2 - MTZ worldwide N2 - The main focus of the project series “Piston Ring Oil Transport” is the investigation of the tribological conditions in the piston assembly. Within the first part of the project, a 0.5-l single-cylinder research engine was built up [1, 2], which is equipped with numerous sensors to measure the tribological circumstances. In the second project part [3] presented here, additional simulation models are developed, which gain accuracy compared to the recorded measurement data and contribute significantly to an understanding of the oil supply at the piston assembly. KW - piston ring Y1 - 2017 U6 - https://doi.org/10.1007/s38313-016-0167-2 SN - 2192-9114 VL - 78 IS - 2 SP - 72 EP - 77 ER - TY - GEN A1 - Fecht, Hans-Jörg A1 - Wunderlich, Rainer A1 - Meier, Martin A1 - Sprenger, Heinz T1 - Measurement of Thermophysical Properties of Metallic Melts for High Quality Castings Y1 - 2001 ER - TY - CHAP A1 - Babcsan, N. A1 - Leitlmeier, D. A1 - Meier, M. A1 - Banhart, J. A1 - Garcia-Moreno, F. ED - Vignes-Adler, Michèle T1 - Measurements on cell walls and Plateau borders of particle stabilized foams T2 - A collection of papers presented at the 5th European Conference on Foams, Emulsions, and Applications, EUFOAM 2004 Y1 - 2005 PB - Elsevier CY - Amsterdam [u.a.] ER - TY - GEN A1 - Butt, Usman A1 - Jehring, Lothar A1 - Egbers, Christoph T1 - Mechanism of drag reduction for circular cylinders with patterned surface T2 - International journal of heat and fluid flow Y1 - 2014 SN - 1879-2278 VL - Vol. 45 SP - 128 EP - 134 ER - TY - GEN A1 - Uhlig, Benedict A1 - Preuß, Ann-Christin A1 - Graf, Johann A1 - Neben, Matthias T1 - Messtechnische und simulative Untersuchung des Ölhaushalts an der Kolbengruppe T2 - MTZ - Motortechnische Zeitschrift N2 - Die Projektreihe Kolbenring-Öltransport dient der Untersuchung der tribologischen Zustände in der Kolbengruppe. Dabei wurde im ersten Projektabschnitt ein 0,5-l-Einzylinder-Forschungsmotor aufgebaut, der mit zahlreichen Sensoren ausgerüstet ist, um diese Zustände messtechnisch zu erfassen. Im zweiten, hier ausschnittsweise vorgestellten Projektabschnitt wurden zusätzliche Simulationsmodelle implementiert, die durch Abgleich mit den aufgezeichneten Messdaten an Genauigkeit gewinnen und zum Verständnis des Ölhaushalts in der Kolbengruppe erheblich beitragen. KW - Kolbenring Y1 - 2017 U6 - https://doi.org/10.1007/s35146-016-0175-4 SN - 2192-8843 SN - 0024-8525 VL - 78 IS - 2 SP - 76 EP - 81 ER - TY - GEN A1 - Meier, Martin A1 - Meyer, Antoine A1 - Mutabazi, Innocent A1 - Egbers, Christoph T1 - Microgravity experiments on thermo-electric flows T2 - 26th European Low Gravity Research Association Biennial Symposium and General Assembly, Granada (Spanien), September 24-27, 2019 Y1 - 2019 UR - https://www-docs.b-tu.de/fg-aerodynamik-stroemungslehre/public/PDF/Pubs/ELGRA2019_Book-of-abstracts.pdf SP - 293 EP - 294 ER - TY - JOUR A1 - Futterer, Birgit A1 - Gellert, Marcus A1 - Huschto, Michael A1 - Larcher, Thomas von A1 - Egbers, Christoph T1 - Microgravity Science on International Space Station (ISS): The Geoflow Experiment Y1 - 2006 ER - TY - CHAP A1 - Futterer, Birgit T1 - Minimierung von Diskretisierungsfehlern bei gitterunabhängiger Elektrodenpositionierung T2 - 62. Jahrestagung der Deutschen Geophysikalischen Gesellschaft im Jahr der Geowissenschaften Y1 - 2002 PB - Deutsche Geophysikalische Gesellschaft CY - Hannover ER - TY - GEN A1 - Kupka, Friedrich A1 - Zaussinger, Florian A1 - Montgomery, M. H. T1 - Mixing and overshooting in surface convection zones of DA white dwarfs: First results from ANTARES T2 - Monthly Notices of the Royal Astronomical Society Y1 - 2018 SN - 1365-2966 SN - 0035-8711 VL - 474 IS - 4 SP - 4660 EP - 4671 ER - TY - THES A1 - Haun, Peter T1 - Modelling of thermo-electro hydrodynamic (TEHD) convection N2 - In Thermo-Electro Hydrodynamics (TEHD), an electric field is applied to a fluid within a heated domain to induce thermal convection. The fluid and the electric field must meet specific conditions to establish a dielectrophoretic force that acts as a buoyancy force on the fluid. This buoyancy force is utilised in experiments to replicate gravitational buoyancy, explore resulting flow structures, or develop heat transfer systems without moving parts. In this study, the electric force field acting on a dielectric fluid in a capacitor is derived from the Maxwell equations and coupled with the Navier-Stokes equation for fluid motion. Furthermore, an Open Source Field Operation and Manipulation (OpenFOAM) solver is extended to incorporate TEHD momentum and energy-contributing terms. In a dimensional analysis, dimensionless parameters are derived and tested. Therefore, parameter studies in 2D approximations of planar and cylindrical geometries are done. Additionally, the 2D investigations are utilised to study the behaviour of heat transfer and boundary layer properties, and some scaling laws are derived. Finally, 3D spherical shell microgravity experiments are analysed and linked to the results of 3D numerical analysis. The results verify the derived methods, which are expanded and applied to the upcoming space experiment, AtmoFlow. Y1 - 2025 SN - 978-3-689-52666-5 U6 - https://doi.org/10.61061/ISBN_9783689526665 PB - Cuvillier Verlag CY - Göttingen ET - 1st edition ER - TY - GEN A1 - Gaillard, Yann A1 - Szabo, Peter A1 - Travnikov, Vadim A1 - Egbers, Christoph T1 - Modelling Thermo-Electrohydrodynamic Convection in Rotating Spherical Shell Using OpenFOAM ® T2 - OpenFOAM® Journal Y1 - 2025 U6 - https://doi.org/10.51560/ofj.v5.136 VL - 5 (2025) SP - 1 EP - 16 ER - TY - CHAP A1 - Zanoun, El-Sayed A1 - Egbers, Christoph A1 - Jehring, Lothar T1 - Modified Optical and Thermal Anemometers for Laminar and Turbulent Boundary Layers Investigation Y1 - 2005 ER -