Optimum kinetic energy dissipation in blood flow in glass capillaries by flow field determination: analysis of curvature effect by axial tomographic and image velocimetry techniques.
Based on the variation in the optical density due to erythrocyte concentration and movement, the axial tomographic and image velocimetry techniques are respectively applied to determine the flow field, i.e., the distribution of erythrocytes and axial and radial velocity components, in steady blood flow through a curved glass capillary with a diameter of 180 microns. The data at four positions (two straight and two curved segments of the capillary) are recorded by a video-microscopic system on a video cassette. The erythrocyte and velocity distribution profiles change from symmetric at the straight position to an asymmetric shape at the curved sections. These profiles become symmetric again at the straight section of the capillary. The increase in the radial velocity component at curved portions is attributed to the secondary flow. The tomograms obtained by concentration profiles show respective changes in the cellular population at various cross-sectional positions. The kinetic energy dissipation, as calculated based on a determination of the flow field, is the minimum for the observed profiles. Any deviation towards parabolic form leads to the dissipation of a higher amount of energy.
Prakash
B
B
Biomedical Engineering Division, Indian Institute of Technology, Madras, Tamilnadu, India.
Singh
M
M
D002196:Capillaries; D004735:Energy Transfer; D018056:Hemorheology; D006801:Humans; D012039:Regional Blood Flow; D014054:Tomography