Turbulence, Wind Energy and Stochastics - TWIST
Contact
Universität Oldenburg
Institute of Physics & ForWind
Küpkersweg 70,
26129 Oldenburg
Prof. Dr. Joachim Peinke
Room, W33 3-302
Fax. +49-(0)441-798-5099
Tel. +49-(0)441-798-5050
Sektr. +49-(0)441-798-5090
Membership
Cooperations and Projects
Turbulence, Wind Energy and Stochastics - TWIST
T. Messmer, M. Hölling, J. Peinke:
Enhanced recovery caused by nonlinear dynamics in the wake of a floating offshore wind turbine
Journal of Fluid Mechanics , Volume 984 , 10 April 2024 , A66
DOI: doi.org/10.1017/jfm.2024.175
Floating wind turbines are one important technology for the further expansion of offshore wind energy. The evolution of the wake generated by such turbines requires better understanding to improve future designs, which we investigate in this study.
The influence of the movements of an idealised floating wind turbine on the wake generated is investigated experimentally in the large wind tunnel at the University of Oldenburg.
The results show that the motion of the floating turbine accelerates the transition to the far-wake and increases wake recovery compared to a fixed turbine. These results are particularly pronounced at low turbulence levels.
T. T. B. Wester, J. Peinke, G. Gülker :
Description of laminar-turbulent transition of an airfoil boundary layer measured by differential image thermography using directed percolation theory
Phys. Rev. Fluids 9, 033903, 2024
DOI: doi.org/10.1103/PhysRevFluids.9.033903
Investigating boundary layer transitions, this study leverages differential image thermography (DIT) and directed percolation theory on a heated airfoil. It highlights DIT's accuracy in detecting transitions and validates the theory's effectiveness in describing turbulence onset, aligning with universal exponents. This approach demonstrates broad applicability in fluid mechanics, suggesting potential as a precise tool for turbulence analysis.
L. Neuhaus, M. Wächter, J. Peinke :
The fractal turbulent–non-turbulent interface in the atmosphere
Wind Energ. Sci., 9, 439–452, 2024
DOI: doi.org/10.5194/wes-9-439-2024
Future wind turbines reach unprecedented heights and are affected by wind conditions that have not yet been studied in detail. With increasing height, a transition to laminar conditions with a turbulent–non-turbulent interface (TNTI) becomes more likely. In this paper, the presence and fractality of this TNTI in the atmosphere are studied. Typical fractalities known from ideal laboratory and numerical studies and a frequent occurrence of the TNTI at heights of multi-megawatt turbines are found.
L. Neuhaus, M. Hölling, W. Bos, J. Peinke :
Generation of Atmospheric Turbulence with Unprecedentedly Large Reynolds Number in a Wind Tunnel
Physical Review Letters 11 Sep 2020 Vol. 125, Iss. 15, Pg. 154503
DOI: doi.org/10.1103/PhysRevLett.125.154503
Press releases:
uol.de/aktuelles/artikel/sturm-im-windkanal-4514
A. Fuchs, S. M. D. Queirós, P. G. Lind, A. Girard, F. Bouchet, M. Wächter, and J. Peinke:
Small scale structures of turbulence in terms of entropy
and fluctuation theorems
Physical Review Fluids 11 Mar 2020 Vol. 5, Iss. 3, Pg. 034602
DOI: doi.org/10.1103/PhysRevFluids.5.034602
"Understanding the wind"
Article in the research magazine EINBLICKE of the University of Oldenburg
P. Veers, K. Dykes, E. Lantz, S. Barth, C. L. Bottasso, O. Carlson, A. Clifton, J. Green, P. Green, H. Holttinen, D. Laird, V. Lehtomäki, J. K. Lundquist, J. Manwell, M. Marquis, C. Meneveau, P. Moriarty, X. Munduate, M. Muskulus, J. Naughton, L. Pao, J. Paquette, J. Peinke, A. Robertson, J. Sanz Rodrigo, A. M. Sempreviva, J. C. Smith, A. Tuohy, R. Wiser:
Grand challenges in the science of wind energy
Science 25 Oct 2019: Vol. 366, Issue 6464, eaau2027
DOI: 10.1126/science.aau2027
J. Peinke, M.R.R. Tabar, M. Wächter:
The Fokker-Planck Approach to Complex Spatiotemporal Disordered Systems
Annual Review of Condensed Matter Physics 2019 10:1
doi.org/10.1146/annurev-conmatphys-033117-054252
H. Haehne, J. Casadiego, J. Peinke, M. Timme:
Detecting Hidden Units and Network Size from Perceptible Dynamics
Phys. Rev. Lett. 122, 158301
doi.org/10.1103/PhysRevLett.122.158301
2017: 100 years of Fokker-Planck-Equation
"The area of turbulence is one of the most challenging research fields in modern science that, despite remaining unsolved, has led to many new innovative concepts and new research fields in a number of disciplines."
"I became interested in turbulent liquid and gas flows at the end of the thirties. From the very beginning it was clear that the theory of random functions of many variables (random fields), whose development only started at that time, must be the underlying mathematical technique. Moreover, I soon understood that there was little hope of developing a pure, closed theory, and because of the absence of such a theory the investigation must be based on hypotheses obtained by processing experimental data."
[1] Planck, M. (1917). "Über einen Satz der statistischen Dynamik und seine Erweiterung in der Quantentheorie". Sitzungsber. Preuss. Akad. Wiss. *24*
[2] By Konrad Jacobs (owpdb.mfo.de/detail?photoID=7493) [CC BY-SA 2.0 de (creativecommons.org/licenses/by-sa/2.0/de/deed.en)], via Wikimedia Commons