Computational fluid dynamics (CFD) plays an essential role to analyze fluid flows and heat transfer situations by using numerical methods. Turbomachines involve internal and external fluid flow problems in compressors and turbines. CFD at present is one of the most important tools to design and analyze all types of turbomachinery. The main purpose of this paper is to review the state of the art work carried out in the field of turbomachinery using CFD. Literature review of research work pertaining to CFD analysis in turbines, compressors and centrifugal pumps are described. Various issues of CFD codes used in turbomachinery and its parallelization strategy adopted are highlighted. Furthermore, the prevailing merits and demerits of CFD in turbomachinery are provided. Open areas pertinent to CFD investigation in turbomachinery and CFD code parallelization are also described.

Computational Fluid Dynamics in Turbomachinery: A Review of State of the Art

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CFD for Centrifugal Pumps: A Review of the State-of-the-Art

Experimental study of gas-liquid two-phase flow patterns within centrifugal pumps impellers

Characterization of a centrifugal pump impeller under two-phase flow conditions

Visualization study of gas–liquid two-phase flow patterns inside a three-stage rotodynamic multiphase pump

The behavior of electric submersible pumps (ESP) handling two-phase flow is a subject of primary concern, especially in the petroleum industry, where significant amounts of free gas may be found in oil wells production. In the past, several attempts were made to predict the performance of such kind of pumps, nevertheless, limited success has been achieved due to the complex flow dynamics inside the impeller Geometry, gas void fraction (GVF) and suction pressure seem to be the main parameters affecting ESP performance. Furthermore, the higher the GVF of the mixture is, the higher the degradation of head that is experienced by the pump. So far, this complex phenomenon has not been well understood. In the present work, a two fluid model is used in three-dimensional (3D) CFD simulations to obtain the pressure, liquid and gas velocity fields as well as the GVF distribution inside an ESP impeller of known geometry; using flow rates, bubble diameter and GVF at the suction as independent variables and an incompressible fluid hypothesis. The gas pocket in the impeller blade reported by other researchers is obtained and comparison with experimental results shows good agreement. The obtained variables from the simulations are the cornerstone that allows the prediction of the performance curve of the pump for different GVF and such, lets the head degradation of the pump be estimated.

CFD Analysis of Electric Submersible Pumps (ESP) Handling Two-Phase Mixtures

Throughout the history of turbomachines investigators have tried to develop reliable methods for prediction of centrifugal pump behavior. Among the parameters available to estimate the performance of this kind of machine is the slip factor. In spite of being regarded as a variable of great significance in the analysis of turbomachinery, there seem to be a misconception regarding its concept and application. Indeed, empirical correlations have been widely used to estimate the slip factor, even in the case of two-phase flow applications, where it has not been investigated. Moreover, these correlations provide a constant value of the slip factor for a given impeller only at the best efficiency point, which is an important restriction to the pump performance prediction, considering that slip factor varies with the pump flow rate. In this study, three-dimensional computational fluid dynamics simulations were carried out on an impeller of known geometry (Ns = 1960) from which values of slip factor were calculated for both single- and two-phase flow (water and water-air). These results include curves of the slip factor as a function of the specific capacity and the gas-void fraction. Additionally, results for the slip factor in the case of single-phase flow (water) are given for various centrifugal impellers (N S = 1157, 1447, 1612, and 3513) in order to illustrate the influence of the flow rate on this parameter.

Slip Factor for Centrifugal Impellers Under Single and Two-Phase Flow Conditions

Behavior of Electric Submersible Pumps (ESP) handling two-phase flow is a subject of primary concern, especially in the petroleum industry, where significant amounts of free gas may be found in oil wells production. Several attempts have been made in order to predict the performance of such kind of pumps, nevertheless, limited success has been achieved due to the complexity of the flow dynamics inside the impeller. Geometry, gas void fraction (GVF) and suction pressure seem to be the main parameters affecting ESP performance. Furthermore, the higher the GVF of the mixture is, the higher the degradation of head that it is experimented by the pump. This complex phenomena is not well understood so far. In this work, a two fluid model is used in 3D CFD simulations carried out in order to obtain the pressure, liquid velocity and gas velocity fields as well as the GVF distribution in an ESP impeller of known geometry; using flow rates, bubble diameter and GVF at the suction as independent variables and an incompressible fluid hypothesis. The gas pocket in the impeller blade reported from other researchers is obtained and comparison with experimental results has shown good agreement. The obtained variables from the simulations are the cornerstone that allows the prediction of the performance curve of the pump for different GVF and in this way, estimate the head degradation of the pump.Copyright © 2002 by ASME

José Caridad

Papers

Characterization of a centrifugal pump impeller under two-phase flow conditions

CFD Analysis of Electric Submersible Pumps (ESP) Handling Two-Phase Mixtures

Slip Factor for Centrifugal Impellers Under Single and Two-Phase Flow Conditions

Performance Analysis of Electric Submersible Pumps (ESP) Handling Two-Phase Mixtures