Sharif Digital Repository

Liver is the largest internal organ of the human body which serves many vital functionalities. Recently, liver-on-a-chip systems have been used to model some of the vital liver specific-functions and to investigate its related diseases. The purpose of the present study was simulation of some of these liver specific functionalities on-a-chip and using the obtained results in predicting hepatocellular functionalities i.e. production of some metabolites and modeling some of the liver-related diseases which have been done numerically and experimentally. Numerical simulations have been developed in two-dimensional and three-dimensional forms. In the 2D simulation, the governing equations i.e.... 

Resistive pulse sensing (RPS) has proved to be a viable method for detection and characterization of micro and nano particles. This method works based on ionic current variation inside nanopores. Modern fabrication methods have introduced different nanopore geometries for resistive pulse sensors therefore studing the effects of geometry on sensing performance of nanaopores is important. Numerical simulation has been used to study a wide variation of nanopore’s geometry configurations and study the physics behind this phenomena. Based on the results, numerical simulation could be used as a fast and easy tool for size determination for nanopore. To compare the sensing performance of different... 

Inlets must decelerate the air with lowest loss and drag together with a given pressure and Mach number with best quality and uniformity to the engine. This is done based on flight Mach number, by an arrangement of shock waves and surfaces gradient in the inlet. Any distortion in the flow field and the inlet geometry parameters may disrupt such arrangement and influence on the inlet performance, in addition, under critical conditions, it might affect the stability of the intakes. Any distortion in the flow field and the inlet geometry parameters may disrupt such arrangement and influence on the inlet performance, in addition, under critical conditions, it might affect the stability of the... 

Discovering new medicines and generally medical researches, are time consuming and expensive. But recent achievements in cell culturing methods and micro and nano-engineering techniques have enabled the researchers to investigate new medicines in a lesser time and price. Huh et al. successfully fabricated the lung on chip device. This device is consisted of three chambers. The middle chamber is separated in two equal parts and side chambers were considered in order to apply normal breathing. Periodic deformation was needed to apply the natural condition of cultured cells by expansion and contraction. Numerical simulation was needed to investigate the properties of flow in this kind of... 

Many species in nature exist which human can reach the aims of flying and swimming by inspiring from them. Observations show that fish can use their especial undulating motions of body/fins to crusing, increase performance, suddenly acceleration, and maneuvering. To design a robot fish and benefit the characteristics and abilities of a live fish, using its real geometry and kinematics in the robot is vital. Therefore, simulations are essential to better exploiting the fish behavior, which can obtain useful consequences by using computational fluid dynamics. In this thesis, first the kinematics of sharks is investigated. Then, investigations are accomplished by utilizing an unsteady finite... 

Often in a vacuum test facility, a supersonic exhaust diffuser uses the energy of the outflow from the nozzle to create and maintain a vacuum condition in the engine test chamber. In this system, the temperature of the motor exhaust gas, which directly hits the diffuser walls, is much higher than the tolerance of the metal body of the diffuser. The purpose of this research is to design a cooling system for thermal protection of diffuser walls of a vacuum simulator using a water-jacket tool. At the beginning of this study, the effective parameters in the design of the water-jacket cooling system were identified. Then, a new algorithm to design and optimize the water-jacket cooling system was... 

Hydraulic fracturing, as an industry-leading technology, has proven to be very efficient in increasing the productivity of oil and gas wells. Therefore, this technology has been taken into attention in recent years and the number of hydraulic fracturing operations has been increasing. In order to enhance the efficiency of this technology, the final transmissibility of the fracture needs to be at the maximum possible value. To do so, proppant injection is the most common way to maintain a fracture open. To achieve a successful hydraulic fracture operation, detailed knowledge of the particle's transport and distribution inside the fracture is needed.In this study, a static fracture geometry... 

The purpose of this study is design and simulation of morphing flap for a slotted airfoil to reduce drag and increase lift. Increasing lift results in a smaller flap for the same lift, resulting in less weight and less drag. Drag reduction due to morphing nature causes growth in aerodynamic efficiency. In this work, a flap designed for 0.2 and 4,700,000 Mach and Reynold numbers, respectively. Our simulation was performed using ANSYS FLUENT flow solver and POINTWISE for grid generation. Here, morphing has been applied by changing the flap mean camber line and slots, so that they have minimum interferences with the flow. For this purpose, the flap mean camber line was discretized and various... 

Due to the suitable performance characteristics and the widespread use of Surface Piercing Propellers (SPPs) in high-speed crafts, many experiments and numerical studies have been conducted in this field. Due to the lack of a comprehensive series similar to conventional propellers in the field of SPPs, in this thesis, it has been tried to personalize the suitable basis by conducting two separate experimental tests in the National Iranian Maritime Laboratory (NIMALA) towing tank and the cavitation tunnel at Sharif University using computational fluid dynamics method and the commercial code STAR-CCM+. For this purpose, a wide range of phenomena and effective parameters on hydrodynamic... 

One of the main components of any solar power plant is the heat storage. Implementing heat storage reduc-es the cost of power generation by increasing the capacity factor of the system. This Thesis aims to analyze the operation of heat storages by modeling latent heat
storage. In this regard, an efficient method named "Method of Characteristics" is utilized. Models developed based on this method are possible to be used for comparison, sensitivity analysis, and optimization due to their low computation time. Sensitivity analysis was carried out based on various parameters such as void fraction, fiUer material size. Results show that using latent heat storage, storage c-apacity is... 

The vortex tube is a simple device that injects compressed gas (air) tangentially into the vortex chamber through one or more injection nozzles. After entering, the flow becomes rotational and an axial cold flow goes towards the cold outlet and a peripheral hot flow goes towards the hot outlet. Besides all the different applications of the vortex tube, the main application of this device is cooling. Here, the goal is to optimize the geometry and physical conditions to improve the performance, which is done by using a commercial software and numerical analysis of a vortex tube to understand the flow physics and optimization. In this research, we use experimental and numerical data for...