Swirl-switching phenomenon in turbulent flow through toroidal pipes
Noorani A, Schlatter P (2016)
Publication Type: Journal article
Publication year: 2016
Journal
Book Volume: 61
Pages Range: 108-116
DOI: 10.1016/j.ijheatfluidflow.2016.05.021
Abstract
Direct numerical simulations (DNSs) are performed to investigate turbulent flows in toroidal pipes with two different curvatures. By means of proper orthogonal decomposition (POD), dominant coherent structures in the flow are identified. The most energetic structures in the strongly curved pipes (with curvature κ=0.1 and κ=0.3 and Reb=11,700 based on bulk velocity and diameter) are very similar in structure for both configurations studied. The dominant modes (shape and frequency) appear to match the coherent structures responsible for the swirl switching phenomenon found earlier in experimental and numerical studies of turbulent flow in spatially developing 90° bends, with which the current results are compared. The fact that turbulence in the toroidal pipe features low-frequency coherent structures very similar to swirl switching is relevant as it may challenge the current hypothesis regarding the origin of swirl switching, which is usually connected to the conditions in the upstream straight section. However, the toroidal pipe is homogeneous in the streamwise direction and does as such not feature a straight part.
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APA:
Noorani, A., & Schlatter, P. (2016). Swirl-switching phenomenon in turbulent flow through toroidal pipes. International Journal of Heat and Fluid Flow, 61, 108-116. https://doi.org/10.1016/j.ijheatfluidflow.2016.05.021
MLA:
Noorani, A., and Philipp Schlatter. "Swirl-switching phenomenon in turbulent flow through toroidal pipes." International Journal of Heat and Fluid Flow 61 (2016): 108-116.
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