BLOOD-FLOW WITH BODY ACCELERATION FORCES
DSpace at IIT Bombay
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Title |
BLOOD-FLOW WITH BODY ACCELERATION FORCES
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Creator |
CHATURANI, P
ISAAC, ASAW |
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Subject |
model
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Description |
Blood Bow with body acceleration forces, studied by Sud and Sekhon [1], has been re-examined. It is observed that Sud and Sekhon [1] have obtained exact analytic solutions for flow variables in terms of Bessels functions with complex arguments. The Bow variables have not been computed from these exact expressions. Perhaps, it might have been thought that the computation of flow variables through these complicated expressions of Bessels functions with complex argument may be very difficult, if not impossible. In the present analysis, we have been able to get the exact analytic solutions for Bow variables as functions of real variables. The evaluation of these exact solutions is not as difficult as expected. The advantage of the exact solution over approximate solutions is two-fold: (a) while calculating Row variables from approximate solutions one has to use two expressions, one for small values of R(ep) and R(eb) (pulsatile and body acceleration Reynolds numbers) and other for large values of R(ep) and R(eb); in contrast to this, in exact solutions one does not have to bother about this switching of expressions; (b) for situations where R(ep) or R(eb) or both are of the order of 2, these approximate solutions can not provide sufficiently accurate results, error is of the order of 15%; in contrast to this, the exact solutions of the present analysis have no such restriction. Further, it is observed that the approximate solution of Sud and Sekhon [1] for large values of R(ep) and R(eb) is incorrect, because it does not satisfy one of the boundary conditions. A term by term analysis of exact numerical solution for low values of R(ep) and R(eb) shows that influence of the oscillatory parts of body acceleration and pressure gradient on Bow is insignificant, about 3%. Hence flow variables can be approximated by only one simple term; this is in contrast with corresponding expression of Sud and Sekhon [1] which has three terms (with an error of about 1%). Another interesting observation of exact solutions is the amplitude of the wall shear tau(omega), predicted by approximate solutions is much smaller (about 25-30% in wide tubes and 11-20% in narrow tubes). This could lead to a wrong estimate for wall damage. An increase in body acceleration frequency leads to a decrease in Bow rate and wall shear amplitude. Finally, it may be remarked that the forms of pressure gradient and body acceleration considered by Sud and Sekhon [1] are much different from the actual forms. Flow investigations with more realistic forms of pressure gradient and body acceleration forms the part of our next communication.
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Publisher |
PERGAMON-ELSEVIER SCIENCE LTD
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Date |
2011-08-23T16:50:30Z
2011-12-26T12:56:31Z 2011-12-27T05:45:22Z 2011-08-23T16:50:30Z 2011-12-26T12:56:31Z 2011-12-27T05:45:22Z 1995 |
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Type |
Article
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Identifier |
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE, 33(12), 1807-1820
0020-7225 http://dx.doi.org/10.1016/0020-7225(95)00027-U http://dspace.library.iitb.ac.in/xmlui/handle/10054/10581 http://hdl.handle.net/10054/10581 |
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Language |
en
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