10487

9682

كارشناسي ارشد

تبديل انرژي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مهندسي مكانيك

1394

هجده، 113ص.: مصور، جدول، نمودار

مهدي نيلي احمدآبادي، ابراهيم شيراني

1394/07/11

احمدرضا پيشه ور، محمود اشرفي زاده

1396/10/04

كتابنامه

مكانيك

مهندسي مكانيك

ID9682

به فارسي و انگليسي

Hybrid Lattice Boltzmann Finite Volume Method for Solving the Flow and Concentration of LDL in Blood Azam Torabi Azam torabi@me iut ac ir Date of Submission 2015 07 27 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors Mahdi Nili Ahmadabadi m nili@cc iut ac ir Ebrahim Shirani eshirani@cc iut ac irAbstractThe increase of Low Density Lipoproteins LDL in blood flow and their concentrations and sediments nearthe vessel wall lead to Atherosclerosis causing cardiovascular diseases Because of the difference in velocitynear the wall of the blood vessel system and the permeability of the wall in different positions LDL surfaceconcentration is different in artery wall Therefore the LDL mass transfer in the arteries could be an effectivestep to understanding the disease process The purpose of this work is to investigate the LDL mass transferin vessel walls using the Lattice Boltzmann Method LBM High Schmidt number of LDL leads to numericalinstability of LBM In order to solve this problem LBM and Finite Volume Method FVM are combined In this hybrid method the blood velocity field is solved by LBM using the single relaxation time SRT model and FVM is used for LDL concentration equation The relationship between the two grids is doneusing interpolation LBM is able to simulate flow and mass transfer for the Schmidt number Sc up to 3000only if the time consuming multi relaxation time is used and for higher Sc number Convergence is notachieved However the purposed hybrid method suggested in this work can be used to solve the problem forSc as high as 107 that this range of Sc has not been simulated yet In order to confirm the results the equationsare also of the hybrid simulation and the available results in the literature and noticeable decrease in CPUtime compared with when the LBM is used for both flow and mass transfer indicates the ability of the hybridmethod Finally Lumen Surface Concentration LSC of LDL in right coronary artery with curved andrectangular shape of stenosis and simple geometry for Newtonian and non Newtonian fluids have numericallyinvestigated The results show the Concentration Polarization CP phenomenon and LSC for Non Newtonianfluid is less than that of Newtonian fluid LSC increases by increasing in filtration rate high blood pressure and decreasing in velocity and wall shear stress At the separation point for Newtonian fluid and at separationand reattachment points for Non Newtonian fluid LSC extremely increases The length of the recirculationregion for non Newtonian fluid is less than that of Newtonian fluid When stenosis starts first it growsrapidly and then slowly goes forward narrowing the section of the vessel The artery with rectangularstenosis has high LSC rise at the beginning and end of stenosis In these points wall shear stress reduced Due to the change in susceptible places for disease development a fix geometry for the growth of stenosiscan t be found Keywords Lattice Boltzmann Method Hybrid Method Finite Volume Method Mass Transfer LDL Schmidt number Stenosis

مهدي نيلي احمدآبادي، ابراهيم شيراني

احمدرضا پيشه ور، محمود اشرفي زاده