Sharif Digital Repository

gas adsorption in porous solids and adsorbent,is the important cases in gas processing industries. Including the removal of compounds such as carbon dioxide, hydrogen sulfide and mercaptans from sour gas in natural gas sweetening industry is of great importance.Also in solving the greenhouse phenomena extraction of gases such as methane and carbon dioxide of important environmental issues.To understand and predict the behavior of the absorption capacity of various adsorbents and thus the possibility of absorption systems, a mathematical model is needed.Library resources available in order to determine the kinetics and thermodynamic processes of gas adsorption on solid absorbents use... 

In this study, the numerical simulation of cavitating flows with compressibility effects is performed. The algorithm employs the multiphase Euler equations with homogeneous equilibrium model. The baseline differential equations system is similar to the one-phase system of equations and comprised of the mixture density, mixture momentums and mixture energy equations. Thephases considered for cavitating flows is liquid-vapor and liquid-gas fields. The system of governing equations is discretized using a cell-centered finite volume AUSM’s upwind scheme. The computations are presented for steady noncavitating/cavitating flows around 1D/2Dproblems for different conditions. A sensitivity study is... 

To answer how large the welfare gains from international trade are, this thesis uses two main ideas: linkages and complementarity. A problem along the production chain can sharply reduce output under complementarity. In such a circumstance, international trade and importing in the sectors which are the weak links of the production chain, help solve this problem. Using a general equilibrium model, it is shown that, the complementarity of the intermediate goods assumption results in much higher welfare gains from international trade compared to similar international trade models which assume the substitutability of the intermediate goods  

In this work a generalized non-equilibrium model of three-phase flow in porous media including gravity as well as capillary terms is developed and used for analysis of Riemann’s problem in several three-phase systems. The proposed model uses the extension of Barenblatt model to three-phase systems considering dynamic effects in both relative permeability and capillary pressure functions. We compare the solution of the Riemann’s problem when non-equilibrium effects are included. While equilibrium formulation develops unstable oscillatory solution in the elliptic region, non-equilibrium solution is smooth and stable. The proposed non-equilibrium model is validated by the experimental data of... 

In the present study, the numerical simulation of 2D inviscid compressible cavitation flow is performed by using the compact finite-difference method. The problem formulation is based on the multiphase compressible Euler equations with the assumption of the homogeneous equilibrium model and the system of baseline differential equations is comprised of the continuity, momentum and energy equations for the vapor-liquid mixture. To complete the system of governing equations, the ideal gas relation is used for the vapor phase and the Tait relation is applied for the liquid phase, and therefore, the compressibility effects are considered for both the vapor and liquid phases. To analyze the flow...