Sound generation by low Mach number flow through pipes with diaphragm orifices. - In: New results in numerical and experimental fluid mechanics IX, (2014), S. 629-637
Large-scale coherent structures in turbulent mixed convective air flow. - In: New results in numerical and experimental fluid mechanics IX, (2014), S. 285-292
Numerical simulation of the air flow and thermal comfort in aircraft cabins. - In: New results in numerical and experimental fluid mechanics IX, (2014), S. 293-301
Numerical simulation of the air flow and thermal comfort in a train cabin. - In: Proceedings of the Second International Conference on Railway Technology: Research, Development and Maintenance, ISBN 978-1-905088-59-1, (2014), Paper 328
Experimental investigation of topological changes in the flow field around high-speed trains with respect to Reynolds number scaling effects. - In: Proceedings of the Second International Conference on Railway Technology: Research, Development and Maintenance, ISBN 978-1-905088-59-1, (2014), Paper 32
Numerical and experimental studies of train geometries subject to cross winds. - In: Proceedings of the Second International Conference on Railway Technology: Research, Development and Maintenance, ISBN 978-1-905088-59-1, (2014), Paper 24
Large scale tomographic particle image velocimetry of turbulent Rayleigh-Bénard convection. - In: New results in numerical and experimental fluid mechanics IX, (2014), S. 525-533
Boundary layer heat transport in turbulent Rayleigh-Bénard convection in air. - In: Proceedings in applied mathematics and mechanics, ISSN 1617-7061, Bd. 14 (2014), 1, S. 657-658
http://dx.doi.org/10.1002/pamm.201410312
Turbulent boundary layer in high Rayleigh number convection in air. - In: Physical review letters, ISSN 1079-7114, Bd. 112 (2014), 12, 124301, insges. 5 S.
Flow visualizations and particle image velocimetry measurements in the boundary layer of a Rayleigh-Bénard experiment are presented for the Rayleigh number Ra 1/4 1.4 × 1010. Our visualizations indicate that the appearance of the flow structures is similar to ordinary (isothermal) turbulent boundary layers. Our particle image velocimetry measurements show that vorticity with both positive and negative sign is generated and that the smallest flow structures are 1 order of magnitude smaller than the boundary layer thickness. Additional local measurements using laser Doppler velocimetry yield turbulence intensities up to I 1/4 0.4 as in turbulent atmospheric boundary layers. From our observations, we conclude that the convective boundary layer becomes turbulent locally and temporarily although its Reynolds number Re [approximately] 200 is considerably smaller than the value 420 underlying existing phenomenological theories. We think that, in turbulent Rayleigh-Bénard convection, the transition of the boundary layer towards turbulence depends on subtle details of the flow field and is therefore not universal.
https://doi.org/10.1103/PhysRevLett.112.124301
Local wall heat flux in confined thermal convection. - In: International journal of heat and mass transfer, ISSN 1879-2189, Bd. 73 (2014), S. 752-760
We report highly resolved measurements of the local wall heat flux in turbulent Rayleigh-Bénard convection using an infrared camera. The measurements have been undertaken in a Rayleigh-Bénard cell with rectangular base of 2.50 m x 0.65 m and a height of 2.5 m which is filled with air. First of all, it could be demonstrated that in a Rayleigh-Bénard cell with rectangular cross-section the time-averaged wall heat flux locally deviates by 30% from its mean. Furthermore, a strong correlation between the global flow structure inside the cell and the distribution of the local wall heat flux could be identified.
https://doi.org/10.1016/j.ijheatmasstransfer.2014.02.033