Three major regimes are identified for particle transport in pipe flow: flow with a stationary particle bed, flow with moving particle bed or dunes, and flow of fully dispersed particle-liquid mixture. In this work, analysis of experimental data showed the flow regimes can be defined by two dimensionless parameters, which are the ratios of the flow velocity and turbulent shear velocity to the particle settling velocity.
A flow regime map was developed by using these two dimensionless parameters. This flow regime map is applicable to a wide range of conditions. In the considered experiments, the size of the solid particles varied from several micrometers to 1 cm, the solids fraction varied from less than 1% to approximately 40%, and the solid phase was formed by different particles, such as glass spheres (1.24 sg) and sand (2.5 to 3.0 sg). The inclination angle of the flow counted from the vertical changed from 0 to 180°.
Three mechanistic models are proposed to simulate the three solid-liquid flow regimes. By integrating the flow regime map and mechanistic models, a numerical workflow for particle transport has been developed, yielding the flow regimes and dynamic parameters, such as total pressure drop, friction pressure drop, and local particle volume fraction. The results of numerical tests have been compared with experimental data and 3D simulations using commercial CFD software.
This mapping method has important applications in sand-related flow assurance problems, such as sand cleaning during heavy oil production. It can also be used in other operations involving solids transport in fluid flow, such as cuttings transport in drilling, proppants transport during hydraulic fracturing, and hydraulic transport of the mining industry.
See more of this Group/Topical: Topical 2: Innovations in Process Research and Development