title: Effects of aortic irregularities on blood flow.
abstract: Anatomic aortic anomalies are seen in many medical conditions and are known to cause disturbances in blood flow. Turner syndrome (TS) is a genetic disorder occurring only in females where cardiovascular anomalies, particularly of the aorta, are frequently encountered. In this study, numerical simulations are applied to investigate the flow characteristics in four TS patient- related aortic arches (a normal geometry, dilatation, coarctation and elongation of the transverse aorta). The Quemada viscosity model was applied to account for the non-Newtonian behavior of blood. The blood is treated as a mixture consisting of water and red blood cells (RBC) where the RBCs are modeled as a convected scalar. The results show clear geometry effects where the flow structures and RBC distribution are significantly different between the aortas. Transitional flow is observed as a jet is formed due to a constriction in the descending aorta for the coarctation case. RBC dilution is found to vary between the aortas, influencing the WSS. Moreover, the local variations in RBC volume fraction may induce large viscosity variations, stressing the importance of accounting for the non-Newtonian effects.
authors.affiliation: Linné FLOW Center, KTH Mechanics, 10044, Stockholm, Sweden. prahl@mech.kth.se.
authors.forename: Lisa
authors.identifier: http://orcid.org/0000-0001-9976-8316
authors.initials: L
authors.lastname: Prahl Wittberg
authors.affiliation: Linné FLOW Center, KTH Mechanics, 10044, Stockholm, Sweden.
authors.forename: Stevin
authors.initials: S
authors.lastname: van Wyk
authors.affiliation: Linné FLOW Center, KTH Mechanics, 10044, Stockholm, Sweden.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Fuchs
authors.affiliation: University of Cincinnati, Cincinnati, OH, 45221, USA.
authors.forename: Ephraim
authors.initials: E
authors.lastname: Gutmark
authors.affiliation: Cincinnati Children's Hospital, Cincinnati, OH, 45229, USA.
authors.forename: Philippe
authors.initials: P
authors.lastname: Backeljauw
authors.affiliation: Cincinnati Children's Hospital, Cincinnati, OH, 45229, USA.
authors.forename: Iris
authors.initials: I
authors.lastname: Gutmark-Little
mesh_terms: D001011:Aorta / Q000503:physiopathology*; D001013:Aorta, Thoracic / Q000503:physiopathology; D003326:Coronary Circulation / Q000502:physiology*; D004912:Erythrocytes / Q000378:metabolism; D018056:Hemorheology; D006801:Humans; D008955:Models, Cardiovascular; D011312:Pressure; D013314:Stress, Mechanical; D014424:Turner Syndrome / Q000473:pathology / Q000503:physiopathology; D014783:Viscosity
keywords: Aortic arch; Blood flow; Non-Newtonian; Numerical simulation; Red blood cell distribution