شبيه سازي جريان خون در شريان كاروتيد با در نظر گرفتن اندر كنش سازه و سيال

چكيده انگليسي :

Numerical Simulation of Blood Flow in Carotid Artery Considering Fluid Structure Interaction Hamed Adib h adibhajbagheri@cv iut ac ir July 18th 2011 Department of Civil Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors M Chamani Assosiate Prof mchamani@cc iut ac ir M Navidbakhsh Assosiate Prof mnavid@iust ac ir AbstractHemodynamic is a branch of fluid mechanics that concerns with the application of blood flow in arterioles Blood flow is more viscous than water arteriole wall is elastic and flow is unsteady In this study numericalsimulation of blood flow in the Carotid artery is carried out for a 54 years old person The geometry used inthis simulation is the actual geometry of the processing computed tomography scan including 34 millimetersof common Carotid artery and 15 millimeters of internal and external Carotid arterioles at the right side of thehead Radius of the common Carotid artery at the inlet is 3 millimeters and at the outlet of the internalCarotid and external Carotid are 2 and 1 5 millimeters respectively Wall thickness in all arterioles areassumed 0 5 millimeters The ANSYS CFX software is used to simulate the blood flow with elastic and rigidwalls hypothesis The whole domain grid includes 86971 cells The time step was set as 0 016 second TwoNewtonian and four non Newtonian models are used for the rheeology of the blood Boundary condition atthe inlet of the Carotid artery is defined as the mass flow and the mass flow is given for one pulse of heartbeep The displacement of input and output boundary condition is set to zero and the velocity at the inlet ofcommon carotid is given as uniform Artery densities were assumed 1060 and 1200 kilogram per cubicmeter Hemodynamic characteristics such as fluid velocity wall shear stress wall displacement and fluidpressure at different sections have been estimated It is shown that the velocity near the wall in the elastic wall models is more than one obtained in the modelwith rigid walls Maximum velocity in the Carotid artery occurs in Carreau Yasuda s method It is observedthat there is an area with largest displacement at the middle of common Carotid artery It is concluded thatthe aneurysm disease in such area is most likely to happen and atherosclerosis has least occurrence Theresults show that there is not any separation zone in the internal Carotid artery because the intersection of theinternal and external Carotid arterioles has low angle about 37 degrees The velocity gradient and the wallshear stress at the exterior wall of the external Carotid artery are low where the conditions for thedevelopment of atherosclerosis commence The wall shear stress increases at the intersection of the internaland external Carotid arterioles In this region the occurrence of aneurysm is more likely to happen than anyother region It is shown that Carreau s and Carreau Yasuda s rhelogical models better estimate thecharacteristics of the blood flow than model with Cross rhelogical model The total pressure static pressureplus dynamic pressure in the internal Carotid is almost constant It is concluded that by analyzing the resultof an actual sample of Carotid artery the cardiovascular disease can be predicted Key Words Carotid Artery Blood Flow Newtonian and Non Newtonian Fluid ANSYS CFX Fluid Structure Interaction

اديب، حامد

شبيه سازي جريان خون در شريان كاروتيد با در نظر گرفتن اندر كنش سازه و سيال

سيال نيوتني و غير نيوتني , ANSYS-CFX