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dc.contributor.advisorMyose, Roy Y.
dc.contributor.authorKok, Foo
dc.date.accessioned2015-11-20T16:45:11Z
dc.date.available2015-11-20T16:45:11Z
dc.date.issued2015-05
dc.identifier.otherd15013
dc.identifier.urihttp://hdl.handle.net/10057/11599
dc.descriptionThesis (Ph.D.)-- Wichita State University, College of Engineering, Dept. of Aerospace Engineering
dc.description.abstractAortocoronary bypass (ACB) surgery is a treatment to bypass a blocked artery using a graft. Approximately 500,000 bypass surgeries are performed in the U.S. each year. Of these, about 15% to 20% have an early-phase failure, typically in the proximal region. A natural question which arises is whether fluid dynamic geometry plays a role in the patency. Since only a few studies have considered proximal region geometry, this motivates the present study. Blood flow in a coronary artery bypass often involves very complex fluid dynamic behavior. Numerical simulation is employed to investigate the flow field environment of the proximal region of a bypass. A series of different branching models with laminar inflow are considered to systematically investigate the geometrical effect under different flow conditions. Model types (with branch diameter to host diameter ratio D2/D1 < 1, with or without blend at the junction) include T-junction and host to branch junction with a radius of curvature with and without helical pitch. Some flow conditions included non-Newtonian blood and non-steady flow. Non-blended T-junction is subjected to flow separation at the inner wall of the branch unless the flow rate ratio (𝑚̇2/𝑚̇1) is high and D2 is small. By employing a blend radius at the T-junction, there is a critical flow rate ratio where separation near the inner wall of the junction can be diminished under steady state flow condition. This parameter is known as (𝑚̇2/𝑚̇1)crit. Given a blended T-junction, there is a common branch radius rB which corresponds to (𝑚̇2/𝑚̇1)crit,min that gives the minimum separation scale under steady state flow condition or delays the onset of separation under non-steady flow conditions. This parameter was found to be independent of Re. A geometric correlation that corresponds to non-separated flow in blended T-junction was developed and can be expressed as rB = 0.146 D21.74. This correlation is independent to flow rate ratio.
dc.format.extentxix, 188 p.
dc.language.isoen_US
dc.publisherWichita State University
dc.rightsCopyright 2015 Foo Kok
dc.subject.lcshElectronic dissertations
dc.titleNumerical analysis of blood flow in an aortocoronary bypass model
dc.typeDissertation


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