Abstract:
:Some investigators have attempted to estimate the Reynolds shear stress on the basis of a single component of velocity. The purpose of this investigation is to determine the validity of such estimates in a complex flow field, such as occurs in the cardiovascular system in the region of the aortic valve. Turbulent velocities were obtained in an in vitro pulse duplicating system with a two-channel laser Doppler anemometer. Velocities were measured in the region of two stenotic natural aortic valves and a normal stent mounted porcine bioprosthetic valve. Constants of proportionality between the Reynolds shear stress, averaged over ejection, and the Reynolds normal stress were determined. The constants of proportionality depended upon the local conditions, namely, whether the valves were stenotic or normal bioprosthetic. There was wide scatter of data. This suggests that any estimate of the Reynolds shear stress, based upon a single axial velocity in a complex flow field, such as occurs in the cardiovascular system, is likely to be inaccurate.
journal_name
Ann Biomed Engjournal_title
Annals of biomedical engineeringauthors
Walburn FJ,Sabbah HN,Stein PDdoi
10.1007/BF02371247subject
Has Abstractpub_date
1985-01-01 00:00:00pages
17-23issue
1eissn
0090-6964issn
1573-9686journal_volume
13pub_type
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