--- res: bibo_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.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Duo foaf_name: Xu, Duo foaf_surname: Xu foaf_workInfoHomepage: http://www.librecat.org/personId=3454D55E-F248-11E8-B48F-1D18A9856A87 - foaf_Person: foaf_givenName: Atul foaf_name: Varshney, Atul foaf_surname: Varshney foaf_workInfoHomepage: http://www.librecat.org/personId=2A2006B2-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0002-3072-5999 - foaf_Person: foaf_givenName: Xingyu foaf_name: Ma, Xingyu foaf_surname: Ma foaf_workInfoHomepage: http://www.librecat.org/personId=34BADBA6-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0002-0179-9737 - foaf_Person: foaf_givenName: Baofang foaf_name: Song, Baofang foaf_surname: Song - foaf_Person: foaf_givenName: Michael foaf_name: Riedl, Michael foaf_surname: Riedl foaf_workInfoHomepage: http://www.librecat.org/personId=3BE60946-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0003-4844-6311 - foaf_Person: foaf_givenName: Marc foaf_name: Avila, Marc foaf_surname: Avila - foaf_Person: foaf_givenName: Björn foaf_name: Hof, Björn foaf_surname: Hof foaf_workInfoHomepage: http://www.librecat.org/personId=3A374330-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0003-2057-2754 bibo_doi: 10.1073/pnas.1913716117 bibo_issue: '21' bibo_volume: 117 dct_date: 2020^xs_gYear dct_identifier: - UT:000536797100014 dct_isPartOf: - http://id.crossref.org/issn/00278424 - http://id.crossref.org/issn/10916490 dct_language: eng dct_publisher: National Academy of Sciences@ dct_title: Nonlinear hydrodynamic instability and turbulence in pulsatile flow@ ...