شبيه‌سازي عددي جداسازي مجموعه ذرات در ميكروكانال مركب متشكل از ناحيه مارپيچ و ناحيه صوتي

چكيده انگليسي :

111 Numerical simulation of separation of particles in the composite microchannel consisting of spiral region and acoustic region Fazel Shabaany f shabaany@me iut ac ir Date of Submission 2018 12 22 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohsen Saghafian Saghafian@cc iut ac irAbstractRecently microfluidic Devices have been used for the separation of particles and cells based on theircapability such as high efficiency the ability to analyze small sample of particles and potential forclinical treatments Precise manipulation of particles and cells within microfluidic channels is usuallybased on dielectrophoresis inertial focusing magnetic tweezers or acoustophoresis In the presentstudy we investigate and simulate the combination of two separator methods in a spiralmicrochannel a kind of inertial separators and separator in the microchannel under the influence ofacoustic wave in three dimension using comsol software In fact the spiral microchannel section is apre separator for microchannel under the influence of acoustic wave In the spiral microchannelsection an initial separation is performed then the particles enter the microchannel under theinfluence of acoustic wave and the final separation of the particles is done in this section Thegoverning equations of acoustic waves are obtained by creating a small perturbation in the steady stateNavier stokes equations therefore one simple way of modeling acoustic waves is to use first orderperturbation theory On the other hand spiral microchannels also cause particle to attain newequilibrium position based on their geometric and mechanical properties by creating lift and dragforces Which is the cause of the spiral geometry The purpose of this study is to investigate theseparation of particles with 10 20 and 30 diameter and constant properties from eachother in a fluid and its use for separation of particles and biological cells through acoustic andhydrodynamic forces in the blood This simulation is in three dimensions and is done for towmethods solving governing equations of acoustic waves by Gorkov force method and solvingHelmholtz equations by Gorkov force method for acoustic waves In this study the effect of particlecollisions with each other and the impact of particles on the walls of the microchannel is notconsidered In addition it is assumed that the motion and forces applied to the particles do not affectthe fluid flow and the acoustic field Many parameters affect this separation including the Deannumber the frequency of the acoustic wave and the diameter of the particles Due to the properties ofthe particles and the chosen dean number increasing the spiral microchannel loops the particles aretransmitted to the upper part of the central axis of the microcanal On the other hand these particlesmove under the influence of acoustic force toward the acoustic pressure nodes Therefore bychanging the number of spiral microchannel loops some particles are separated from the otherparticles by the spiral microchannel section Then when the particles arrive into the part under theinfluence of the acoustic wave they are separated further by the acoustic force The results show thatthe separation of particles from this hybrid system can also be accomplished with a 100 separationrate Keywords Acoustic wave Spiral microchannel Micro particles Constant Properties

شعباني، فاضل

شبيه‌سازي عددي جداسازي مجموعه ذرات در ميكروكانال مركب متشكل از ناحيه مارپيچ و ناحيه صوتي

موج صوتي , ميكروكانال مارپيچ , ميكروذرات , خواص ثابت