Interphase force analysis for air-water bubbly flow in a multiphase rotodynamic pump

Abstract

(2015),"Comparative study of SGS models for simulating the flow in a centrifugal-pump impeller using single passage", Engineering Computations, Vol. 32 Iss 7 pp. 2120-2135 <a href="https:// doi.org/10.1108/EC-09-2014-0193">https://doi.org/10.1108/EC-09-2014-0193</a> Access to this document was granted through an Emerald subscription provided by All users group For AuthorsIf you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation.*Related content and download information correct at time of download. Purpose -Interphase forces between the gas and liquid phases determine many phenomena in bubbly flow. For the interphase forces in a multiphase rotodynamic pump, the magnitude analysis was carried out within the framework of two-fluid model. The purpose of this paper is to clarify the relative importance of various interphase forces on the mixed transport process, and the findings herein will be a base for the future study on the mechanism of the gas blockage phenomenon, which is the most challenging issue for such pumps. Design/methodology/approach -Four types of interphase forces, i.e. drag force, lift force, virtual mass force and turbulent dispersion force (TDF) were taken into account. By comparing with the experiment in the respect of the head performance, the effectiveness of the numerical model was validated. In conditions of different inlet gas void fractions, bubble diameters and rotational speeds, the magnitude analyses were made for the interphase forces.Findings -The results demonstrate that the TDF can be neglected in the running of the multiphase rotodynamic pump; the drag force is dominant in the impeller region and the outlet extended region. The sensitivity analyses of the bubble diameter and the rotational speed were also performed. It is found that larger bubble size is accompanied by smaller predicted drag but larger predicted lift and virtual mass, while the increase of the rotational speed can raise all the interphase forces mentioned above. Originality/value -This paper has revealed the magnitude information and the relative importance of the interphase forces in a multiphase rotodynamic pump.

A Review of Experiments and Modeling of Gas-Liquid Flow in Electrical Submersible Pumps

“…Magnitude analysis of interface forces by CFD simulations [112], (a) magnitude ratios of non-drag forces to drag force; (b) bubble size effect on drag force magnitude. pressure increased by 4% for single-phase flow and 23% for two-phase flow at inlet GVF = 20% by optimizing the meridional profile and number of blades.…”

“…pressure increased by 4% for single-phase flow and 23% for two-phase flow at inlet GVF = 20% by optimizing the meridional profile and number of blades. Yu et al [112,113] conducted unsteady numerical simulation on gas-liquid flow in a multiphase centrifugal pump. Considering multiple interfacial momentum transfer components, such as drag force, lift force, virtual mass force (VMF) and turbulent dispersion force (TDF), they concluded that the two-fluid multiphase model was able to capture the transport process more accurately than the homogeneous model.…”

“…Figure 15. Magnitude analysis of interface forces by CFD simulations [112], (a) magnitude ratios of non-drag forces to drag force; (b) bubble size effect on drag force magnitude.…”

Numerical Study of Pressure Fluctuation in a Gas- Liquid Two-Phase Mixed-Flow Pump

“…As shown in Table 2, the pressure fluctuation coefficients at corresponding points C 1 -C 3 increase as IGVF increases. On the one hand, this is because their locations are relatively far away from the rotor-stator interaction region, thus the influence of the rotor-stator interaction is weak; on the other hand, taking into account the rotation effect of impeller, the interaction mode between the gas and liquid is more complicated as IGVF increases [25] Figure 6. It can be seen that the average pressure of point C 4 decreases as IGVF increases.…”

“…In the normal running phase of a pump, with the condition of small bubble size or low spin velocity of the bubbles, the Basset effect and the Magnus effect can be neglected [23,24]. In addition, the turbulent dispersion force can also be neglected according to the magnitude analysis by Yu et al [25]. Therefore, the interphase force herein is associated only with drag, lift, and virtual mass.…”