Widest scales in turbulent channels

Pozuelo R, Cavalieri A, Schlatter P, Vinuesa R (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Physics of Fluids American Institute of Physics (AIP)

Book Volume: 36

Article Number: 025150

Journal Issue: 2

DOI: 10.1063/5.0189532

Abstract

The widest spanwise scales in turbulent channel flows are studied through the use of three periodic channel-flow simulations at friction Reynolds number Re τ = 550 . The length and height of the channels are the same in all cases ( L x / h = 8 π and L y / h = 2 , respectively), while the width is progressively doubled: L z / h = { 4 π , 8 π , 16 π } . The effects of increasing the domain width cannot be determined with statistical significance in our simulations, since the difference in the statistics between the simulations is of the same order as the errors of convergence. A channel flow similar to the smaller one [Del Álamo et al., “Scaling of the energy spectra of turbulent channels,” J. Fluid Mech. 500, 135-144 (2004)], which was averaged over a very long time, was used as a reference. The one-dimensional spanwise spectrum of the streamwise velocity is computed with the aim of assessing the domain-size effect on the widest scales. Our results indicate that 90% of the total streamwise energetic fluctuations is recovered without a significant influence of the size of the domain. The remaining 10% of the energy reflects that the widest scales in the outer layer are the ones most significantly affected by the spanwise length of the domain. The power-spectral density for kz = 0 remains constant even if the size of the domain in the spanwise direction is increased up to four times the standard spanwise length, indicating that wide, spanwise coherent structures are not an artifact of domain truncation.

Authors with CRIS profile

Philipp Schlatter Lehrstuhl für Strömungsmechanik (LSTM)

Involved external institutions

Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH)

Sweden (SE) Instituto Tecnológico de Aeronáutica

Brazil (BR)

How to cite

APA:

Pozuelo, R., Cavalieri, A., Schlatter, P., & Vinuesa, R. (2024). Widest scales in turbulent channels. Physics of Fluids, 36(2). https://doi.org/10.1063/5.0189532

MLA:

Pozuelo, R., et al. "Widest scales in turbulent channels." Physics of Fluids 36.2 (2024).

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