جستجوی مقالات مرتبط با کلیدواژه « دوفاز » در نشریات گروه « مکانیک »

This paper introduces a novel approach to enhance the performance of a two-phase steam and air ejector through primary supersonic nozzle designs with uncircular cross-sections. Experimental tests evaluated the impact of these novel nozzle designs ،which included a star shape ،a simple square ،a square skewed in the direction of the nozzle axis ،a special sketch ،and a simple circular cross-section as the reference nozzle ،on the ejector's performance. The results indicated that the novel nozzles demonstrated the capability to enhance the ejector's entrainment ratio by up to 12% compared to the conventional circular cross-section reference nozzle. To validate and gain further insights into the novel nozzle designs ،computational fluid dynamics (CFD) simulations were also conducted. The integration of CFD simulations and experimental data showcased the potential of these uncircular cross-section nozzles to improve the ejector's performance. The findings offer promising opportunities for optimizing ejector configurations ، paving the way for more efficient and innovative solutions in various engineering applications.

The inducer is an axial Turbo-machinery installed at the inlet of Rotary Gas Separators of Electrical Submersible Pump to increase the head and overcome the pressure drop of the outlet pipes. In this study the inducer optimization in order to increase the head and the efficiency has been addressed using the computational fluid dynamics,. After the initial design, the inlet angle and outlet angle on the shroud, the position of the leading edge and trailing edge on the shroud as well as the blade thickness, selected as effective parameters. To reduce the computational cost a Surrogates model based on the Kriging model is used to predict the objective function. Flow analysis of the single and two phases are conducted by solving three-dimensional steady Navier–Stokes equations. Inhomogeneous two-phase flow is modeled in the ANSYS-CFX software using the Euler-Euler approach and considering interphase forces. From the genetic algorithm, the values of the parameters in the optimal points are calculated and the results are used for sensitivity analysis. Regarding the sensitivity analysis, the input angle and the blade thickness have the greatest impact on the head and also the outlet angle has the greatest impact on the inducer efficiency. Numerical simulation results show that the optimum geometry in single-phase and two-phase conditions provide more head.

Underbalanced drilling and managed pressure drilling with foam have been gained attention of the world oil companies due to its many benefits. The advantages of this method include oil and gas production during drilling, high-speed drilling, drill bit life increase, better cutting transfer and reduced formation damage. In this paper cutting handling by foam was investigated in which foam was assumed to be a homogeneous, single-phase, compressible and non-Newtonian fluid whose rheological properties can be well described by power law model. The assumptions and governing equations of transient two-fluid model were expressed in Euler-Euler coordinate for fluid-particle (foam-cuttings). The upstream method is used to discretizing the equations and the results of the numerical solution are reported in the form of pressure, speed, cutting concentration, quality and density of the foam logs along the well. The impact of back-pressure, ROP, injection rate of gas and liquid, shape and size of cuttings, water influx and oil production on cutting concentration and bottom-hole pressure have been investigated. With increasing parameters such as back-pressure, liquid and gas flow rate, size of the cuttings and ROP, bottom hole pressure and cutting concentration increases. Cutting concentration decreases with increasing liquid and gas flow rate and increases by increasing back-pressure, cutting size and ROP. For validating, the results of the numerical solution are compared with field data obtained from well FR-1 located in the Santa Catarina state of Brazil which show about 16.5 percent errors.