TY - JOUR
T1 - Stratified multiphase model for blood flow in a venular bifurcation
AU - Das, Bigyani
AU - Enden, Giora
AU - Popel, Aleksander S.
N1 - Funding Information:
Acknowledgment--The authors thank Dr. Paul C. Johnson for numerous discussions of in vivo effects of red blood cell aggregation. This work was supported by the National Institutes of Health Grant HL18292 and by Postdoctoral Training Grant 5T32 HL07581 (to B.D. and G.E.). Address correspondence to B. Das, Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, 720 Rutland Avenue, Baltimore, MD 21205, U.S.A. (Received 27Sep95, Revised 13Dec95, Revised 26Feb96, Accepted 23Apr96) Variation of the postcapillary resistance with blood flow is crucial for maintaining capillary blood pressure within an effective range and thereby maintaining fluid balance.
PY - 1997/1/1
Y1 - 1997/1/1
N2 - Available in vitro and in vivo experimental observations suggest that red cell aggregation and blood vessel geometry are important determinants of the flow characteristics of blood in venules. However, no consistent relationship has been observed between red blood cell aggregation and vascular resistance. The present work attempts to understand this relationship by evaluating computationally the effect of red cell aggregation on the flow characteristics of blood in a converging vessel bifurcation. The proposed mathematical model considers blood as a two-phase continuum, with a central core region of concentrated red cell suspension that is surrounded by a layer of plasma adjacent to the vessel wall. In the central core region, blood is described by Quemada's non-Newtonian rheological model, in which local viscosity is a function of both the local hematocrit and a structural parameter that is related to the size of red blood cell aggregates. Fluids from the two feeding branches are immiscible, which results in a stratified multiphase flow in the collecting venule. Calculations predict a complex, three-dimensional pattern of blood flow and generally nonaxisymmetric distribution of velocity, hematocrit, and shear stress in the collecting venule. The calculations are a first step toward a realistic model of blood flow in the venous microcirculation.
AB - Available in vitro and in vivo experimental observations suggest that red cell aggregation and blood vessel geometry are important determinants of the flow characteristics of blood in venules. However, no consistent relationship has been observed between red blood cell aggregation and vascular resistance. The present work attempts to understand this relationship by evaluating computationally the effect of red cell aggregation on the flow characteristics of blood in a converging vessel bifurcation. The proposed mathematical model considers blood as a two-phase continuum, with a central core region of concentrated red cell suspension that is surrounded by a layer of plasma adjacent to the vessel wall. In the central core region, blood is described by Quemada's non-Newtonian rheological model, in which local viscosity is a function of both the local hematocrit and a structural parameter that is related to the size of red blood cell aggregates. Fluids from the two feeding branches are immiscible, which results in a stratified multiphase flow in the collecting venule. Calculations predict a complex, three-dimensional pattern of blood flow and generally nonaxisymmetric distribution of velocity, hematocrit, and shear stress in the collecting venule. The calculations are a first step toward a realistic model of blood flow in the venous microcirculation.
KW - Hemorheology
KW - Mathematical model
KW - Quemada model
KW - Venous microcirculation
UR - http://www.scopus.com/inward/record.url?scp=0031035940&partnerID=8YFLogxK
U2 - 10.1007/bf02738545
DO - 10.1007/bf02738545
M3 - Article
AN - SCOPUS:0031035940
SN - 0090-6964
VL - 25
SP - 135
EP - 153
JO - Annals of Biomedical Engineering
JF - Annals of Biomedical Engineering
IS - 1
ER -