Sharif Digital Repository

In this study a new SPH model for solving free surface and fluid-fluid interaction problems is presented. The numerical model is capable of simulating two dimensional hydraulic problems with arbitrary boundary and initial conditions and large number of particles. It has the ability to model multi-fluids domain with different densities and viscosities. Several corrections are implemented in SPH formulation such as treatment of free surface and correction of viscous term in order to conserve the angular momentum. Several examples are conducted in fluid-fluid domains to measure the capability of model in this area of study. This new model use Incompressible SPH method for more accurate... 

The present study aims at investigating the stability of flexible spinning cylinders conveying flow in an external fluid Medium. Using the linearized Navier-Stokes equations for the flow, a two-dimensional model is developed governing the fluid motion. The resultant force exerted on the flexible cylinder wall due to the fluid interactions is calculated as a function of the lateral acceleration. Applying the Hamilton principle, the governing equations of flexural vibration of the rotary flexible cylinder mounted on simply supported axles are derived. Having the forces due to the conveying fluid calculated and substituting into the governing equations, a coupled field governing equations of... 

Visual investigation of the low salinity water injection into micromodel is the goal of this research. Although many researches have been performed to realize the dominating mechanism behind the increased oil recovery after low salinity water injection, many contradictions exist among the studies. Mechanisms are generally divided into two classes. One class is due to fluid/fluid interactions and the other one is due to fluid/rock interactions. A comprehensive set of experiments are conducted in this study to find out the dominating mechanism behind low salinity water injection under the existing conditions of the experiments. Effect of different wettability condition and presence and absence... 

Many of oil reservoirs in Iran that are fractured, do not have high Recovery Factor (RF), therefor Enhanced Oil Recovery (EOR) methods are exerted in them. In fractured reservoirs, due to high capillary pressure in matrix and low amount of it in fracture, the wetting phase tends to imbibe to the matrix from the fracture. Altering the wettability of reservoir rock from Oil-Wet (OW) to Water-Wet (WW) enables the injected water to imbibe to matrix and sweep its oil. Also reducing oil/water IFT turns oil to small droplets, helps them to pass narrow pores and be produced. In one of the new EOR methods called chemical EOR, chemical additives are injected to the reservoirs along with water to... 

Low salinity water injection is one of the new and important methods of enhancing oil recovery. Experimental studies show the fact that the change in water salinity affects the interfacial properties of water-oil (Fluid-fluid interactions) And the change in wettability that represents the porous media (Rock-fluid interactions) is effective for Oil-recovery. Recently, progress have been made in simulating the process of injecting low-salinity water into the field or core dimensions. However, the simulation of the low salinity water injection process has been much less studied considering the fluid / fluid and fluid / rock interactions at the pore scale. The purpose of this study is to... 

Recent studies have shown that the injection of low-salinity water would enhance the oil recovery factor for both the core scale and the field test. The evidence obtained from laboratory studies showed that the control of salinity and the composition of injected water has successfully affected the oil release, hence enhancing the oil recovery efficiency. In this method, by changing the type and amount of dissolved ions in the injected water, the water/oil/rock interactions are altered. Based on this, extensive studies have been focused on the mechanisms for the trapped oil release at the pore scale. Several mechanisms have been proposed to explain this phenomenon, which can be divided...