Characterization of Microparticle Suspension Using Experimental and Image Processing Methods

, M.Sc. Thesis Sharif University of Technology Rohani, Ramtin (Author) ; Saeedi, Mohammad Hasan (Supervisor) ; Shafiee, Mohammad Behshad (Co-Advisor)

Abstract

Various application of polyethylene material in different industries caused to modern techniques for controlling and measuring specifications of micro-particle suspension. Many industries try to increase stability of suspensions in front of their phase separation.
Because of the consequences of suspension homogeneity, at first, we measured this property. Then, the stability was tested by three different methods. In the first method, the transmitted laser light was measured to assay the suspensions stability. In the second, number of sediments of particles was counted. Sedimentation velocity of particles was measured directly by using a horizontal microscope as the third method. The...

CFD Simulation of Dispersed Drops in Contact with Different Coalescers for Liquid-Liquid Separation

, M.Sc. Thesis Sharif University of Technology Mehdizadeh Chelebari, Yasin (Author) ; Farhadi, Fathollah (Supervisor)

Abstract

Liquid-Liquid coalescers are devices used for increasing the droplet size of the dispersed phase in continuous phase flow such as water droplets in oil flow. The scope of this work is a literature study on the coalescence phenomenon and CFD modeling in general. A mathematical model for simulating coalescence of water droplets in continuous oil flow by the use of different commercial coalescers. The basis for the model are plate-type coalescer and swirl-based coalescer. So, the simulations are done by Eulerian-Lagrangian method. Different aspects of the performance of the coalescers are studied on the rate of coalescence such as impact of changing droplet’s inlet diameters, impact of the...

Prediciton of Suspensions Bulk Viscosity Using Immersed Boundary Approach in the Framework of the Lattice Boltzmann Method

, Ph.D. Dissertation Sharif University of Technology Farnoush, Somayeh (Author) ; Taghizadeh Manzari, Mehrdad (Supervisor)

Abstract

In this study, bulk viscosity of suspensions is predicted using numerical simulation.The elaborated numerical method consists of the lattice Boltzmann (LB) method for fluid matrix simulation and the immersed boundary (IB) method for solid boundary implementation. In order to successfully implement the IB method in the frame-work of the LB method, two important challenges, which are body force modeling in the LB method and numerical velocity slip on solid boundaries, are discussed. As a first challenge, body force modeling in the LB method is studied by using a uni-fied framework which has been devised in this study. Using this unified framework,firstly, errors of different body force...

Investigating Rheology of Microgels in Dilute and Concentrated Suspensions

, M.Sc. Thesis Sharif University of Technology Etemadi Dailami, Mohammad Hossein (Author) ; Mohammadi, Ali Asghar (Supervisor)

Abstract

For designing a unit operation, knowledge about physical properties is essential. This is attained either by direct measurement, which needs spending time and cost or, using proposed correlations. This project is subjected to theoretical analysis of viscosity as the most important rheological property of dilute suspensions of microgels, or in other words colloidal suspensions of porous spheres. They are applied in drug delivery, enhanced oil recovery, synthesis of catalyst and adsorption of heavy metal ions from aqueous systems for water purification purposes. In dilute suspensions particles are faraway from each other and there is no interaction between them therefore, it is better to...