Sharif Digital Repository

Nowadays, cancer, which has been mentioned as the disease of the century, is the second leading cause of death throughout the world, and its incidence is constantly increasing. Isolation of circulating tumor cells is one of the most critical steps in diagnosing and controlling cancer progression. Due to the rarity of cancer cells compared to other cells in the blood sample, the isolation process requires optimal and high-precision devices. With the advent of inertial microfluidics, the ability to control the particles movement, the processing of blood samples as quickly and accurately as possible, and the viability of cells with a high percentage, introduced microfluidic systems as a... 

A finite volume algorithm to assess hydrodynamic aspects of a rigid and up to three degrees of freedom marine structure in the context of transient two-phase flow o viscous incompressible fluids is presented. Different components of the algorithm are selected just after a complete review of all probable choices. Using a collocated arrangement to save data, a fractional step method is applied to satisfy Navier-Stokes and continuity equations, as an appropriate choice in transient flows. Also, a volume fraction transport equation is solved to capture large and complex deformations of the interface between two phases. So, an effective fluid is introduced by combining two immiscible phases in... 

In the present study a through comparison has been made between different free surface modeling methods. Methods for improving the current schemes are analyzed and studied. Among different proposed methods and based on the current in-house CFD solver’s limitations and capabilities, the Flux-Blending Strategy has been used for interface capturing in the framework of the Finite Volume Method (FVM). The proposed scheme has been coupled with other algorithms for improving the capabilities and functionality of the general computational fluid dynamic software, NUMELS, in order to simulate fluid flows with sharp interface.
The improved interface capturing scheme uses the continuous switching... 

The Present Study Deals With The Numerical Modeling Of Free Surface Flows Using Unstructured Grids, That Is An Extension Of Later Studies At Research Institute Of Marine Engineering With The Goal Of Developing A Robust CFD Code. One Of The Most Applicable Aspects Of This Software Is Simulation Of Ship Maneuver And Calculation Of Hydrodynamic Resistance Of Floating Structures That Arises From Combination Of Equations Governing The Flow And 6DOF Rigid Body Equations. This Study Represents Some Proposed Algorithms For Solving Navier-Stokes Equations, Volume Fraction Equation And Rigid Body Equations In A Time Marching Manner. These Equations Are Discretized Based On A Collocated Arrangement For... 

One of the most important components of the noise produced by ships is the propeller noise, which reducing it can significantly reduce the overall noise of the ship. The purpose of this research is to reduce the propeller noise by combining the boundary element method, solving noise equations, and inverse method. In the first section of this thesis, a numerical flow solver software is developed that solve the flow around the impeller using the boundary element (panel) method and calculate the pressure distribution, velocity distribution, thrust, and torque of the propeller. Results show that for low skew and rake propellers, the error of numerical results is between 4 to 7 percent, and for... 

Nowadays, the use of gas turbines with low capacity have acceptance in large quantity. This type of gas turbines with a capacity of approximately 5-200kW are known as microturbines. This type of turbines due to the existence of limitations on increasing of turbine inlet temperature and compressor pressure ratio has low efficiency compared to the turbine with high capacity. Therefore the use of a recuperator in the cycle is necessary. Optimum design of heat recuperator has important effect on improving of gas turbine cycle efficiency. In this project for optimum design of heat recuperator, the effect of recuperator on gas turbine cycle efficiency is studied. By determining geometric... 

The Study of antecedents and considering the status of Project-Based Organizations (PBOs) in our country such as MSA, Azarab, Sadad Machine, etc indicates that they are facing lots of problems in different aspects. This bad situation is in a way that amendment of part of sections guarantees the continuity of bad performance of these companies and we have to apply Business Process Reengineering and establishing a radical change in these firms. So the present research according to managers and experts opinions, several year observations of the writer and review of the literature of BPR, Project Management (PMBOK) and PBOs; and based on a library research, introduces the processes of PBOs in 3... 

In this thesis fluid flow stability will be studied using Chebychev collocation spectral method. In general instability occurs between layers of a single fluid or at the interface of two different fluids. In case of an unstable flow small imposed perturbations on the flow will grow with time and their amplitudes will grow larger. Instability in most cases is an unfavorable phenomenon and therefore should be avoided.Two-phase flow processes in horizontal or vertical pipes under various conditions like natural or forced convection are of considerable importance in industrial applications. Two-phase flow can be found in many devices and industries like boilers, nuclear reactors, cooling and...