In tissue, medical, or dental engineering, when blood comes into contact with a new artificial material, the flow may be influenced by surface tension between the blood and the surface of the material. The effect of surface tension on the flow of blood is significant, especially in microscale. The leading edge of the flowing blood is the triple point where the blood, the material surface, and a stationary gas or fluid meet. The movement of the triple point, i.e., the advancing front of the flow, is driven by surface tension, resisted by viscous shear stress, and balanced by the inertial force (−mass×acceleration). In this article, the dynamics is illustrated in detail in the case of blood flowing into a capillary tube by contact. The capillary tube draws the blood into it. It is shown theoretically that initially the flow of blood in the capillary has a large acceleration, followed by a relatively large deceleration over the next short period of time, then the acceleration becomes small and oscillatory. The velocity history appears impulsive at first, then slows down. The history of the length of blood column appears smooth after integration. Existing solutions of the Navier–Stokes equation permit the analysis of simpler cases. Further fluid mechanics development is needed to meet the practical needs of bioengineering. The importance of experimental study of surface tension and contact angle over a biological surface or a man-made material as a future direction of research is pointed out.

Issue Section:
Technical Papers
Keywords:
surface tension, drops, haemorheology, Navier-Stokes equations, physiological models
Topics:
Blood, Blood flow, Flow (Dynamics), Fluids, Surface tension, Drops
1.
Fung, Y. C., 1990, “How Does the Baby Catch Its First Breaths?” in: Engineering Science: Fluid Dynamics, G. T. Yates, ed., World Scientific Publishing Co., Singapore, pp. 135–145.
2.
Fung
,
Y. C.
,
1975
, “
Does the Surface Tension Make the Lung Inherently Unstable?
”
Circ. Res.
,
37
, pp.
497
–
502
.
3.
Tong, P., and Fung, Y. C., 1965, “The Effect of Wall Elasticity and Surface Tension on the Forced Oscillations of a Liquid in a Cylindrical Container,” in: Fluid Mechanics and Heat Transfer Under Low Gravity, Cohan, H., and Rogers, M., eds., Lockheed Corp., Los Angeles, pp 11-1 to 11–41.
4.
Zupkas, P., 1977, “Mathematical Analysis of Surface Tension Diagrams of Mammalian Lung Components,” M. S. Thesis, University of California, San Diego.
5.
Yih, C. S., 1988, Fluid Mechanics, A Concise Introduction to the Theory, West River Press, Ann Arbor, MI.
6.
Yih
,
C. S.
,
1995
, “
Kinetic-Energy Mass, Momentum Mass, and Drift Mass in Steady Irrotational Subsonic Flow
,”
J. Fluid Mech.
,
297
, pp.
29
–
36
.
7.
Yih
,
C. S.
,
1996
, “
Added Mass
,”
Chinese J. Mech.
,
12
, pp.
9
–
14
.
8.
Lew
,
H. S.
, and
Fung
,
Y. C.
,
1969
, “
On the Low-Reynolds-Number Entry Flow in a Circular Cylindrical Tube
,”
J. Biomech.
,
2
, pp.
105
–
119
.
9.
Lew
,
H. S.
, and
Fung
,
Y. C.
,
1970
, “
Entry Flow Into Blood Vessels at ArbitraryReynolds Number
,”
J. Biomech.
,
3
, pp.
23
–
38
.
10.
Fung, Y. C., 1997, Biomechanics: Circulation, Springer, New York, pp. 291–307.
11.
Purday, H. F. P., 1949, An Introduction to the Mechanics of Viscous Flow (Streamline Flow), Dover Publications, Inc., New York.
12.
Fung, Y. C., 1993, Biomechanics: Mechanical Properties of Living Tissues, Springer, New York, pp. 66–105.
1.
Thurston
,
G. B.
,
1973
, “
Frequency and shear rate dependence of viscoelasticity of human blood
,”
Biorheology
,
10
, pp.
375
–
381
.
2.
Also,
1976
,
13
, pp.
191
–
199
;
3.
1978
,
15
, pp.
239
–
249
;
4.
1979
,
16
, pp.
149
–
162
.
1.
Thurston
,
G. B.
,
1976
, “
The Viscosity and Viscoelasticity of Blood in Small Diameter Tubes
,”
Microvasc. Res.
,
11
, pp.
133
–
146
.
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