Nonlinear hydrodynamic instability and turbulence in pulsatile flow

Xu D, Varshney A, Ma X, Song B, Riedl M, Avila M, Hof B (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Proceedings of the National Academy of Sciences of the United States of America National Academy of Sciences

Book Volume: 117

Article Number: 11233

Journal Issue: 21

DOI: 10.1073/pnas.1913716117

Abstract

Pulsating flows through tubular geometries are laminar provided that velocities are moderate. This in particular is also believed to apply to cardiovascular flows where inertial forces are typically too low to sustain turbulence. On the other hand, flow instabilities and fluctuating shear stresses are held responsible for a variety of cardiovascular diseases. Here we report a nonlinear instability mechanism for pulsating pipe flow that gives rise to bursts of turbulence at low flow rates. Geometrical distortions of small, yet finite, amplitude are found to excite a state consisting of helical vortices during flow deceleration. The resulting flow pattern grows rapidly in magnitude, breaks down into turbulence, and eventually returns to laminar when the flow accelerates. This scenario causes shear stress fluctuations and flow reversal during each pulsation cycle. Such unsteady conditions can adversely affect blood vessels and have been shown to promote inflammation and dysfunction of the shear stress-sensitive endothelial cell layer.

Authors with CRIS profile

Duo Xu Lehrstuhl für Strömungsmechanik

Involved external institutions

Universität Bremen DE Germany (DE) Institute of Science and Technology Austria (IST Austria) AT Austria (AT) Tianjin University (TJU) / 天津大学 CN China (CN)

How to cite

APA:

Xu, D., Varshney, A., Ma, X., Song, B., Riedl, M., Avila, M., & Hof, B. (2020). Nonlinear hydrodynamic instability and turbulence in pulsatile flow. Proceedings of the National Academy of Sciences of the United States of America, 117(21). https://dx.doi.org/10.1073/pnas.1913716117

MLA:

Xu, Duo, et al. "Nonlinear hydrodynamic instability and turbulence in pulsatile flow." Proceedings of the National Academy of Sciences of the United States of America 117.21 (2020).

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