Numerical and Experimental Simulation of Transitional Flow in a Blood Vessel Junction

Abstract

Transitional flow within a subject-specific arteriovenous graft is examined through direct numerical simulation and experimental techniques. Simulations employing the spectral element method are conducted at Reynolds number 1,200 with two different flow divisions under a Newtonian fluid assumption. Laser Doppler anemometry is used to experimentally measure velocity in an optically clear rigid model with the same geometry. Good agreement is observed for both flow divisions with respect to time-averaged and fluctuating velocity. The flow field is characterized by a high-speed jet along the floor, flow separation, and a generally complex three-dimensional flow pattern. These results are novel in that they represent the first detailed comparison between experiments and numerical simulations for transitional flow within a subject-specific blood vessel junction.

This work was supported by the Whitaker Foundation (RG-01-0198); the National Institutes of Health, RO1 Research Project Grant (2RO1HL55296-04A2); the Mathematical, Information, and Computational Sciences Division subprogram of the Office of Advanced Scientific Computing Research, Office of Science, U.S. Department of Energy, under Contract W-31-109-Eng-38; the NSF Pittsburgh Supercomputing Center; and the National Center for Supercomputing Applications. The authors thank Edith Gomez for her help with construction of the experimental flow rig, Sebastien Nicolaon and Steven Cespedes for their help in acquiring the LDA velocity measurements, and Wojciech Kalata for help with the experimental flow model construction.