Computational Modeling of Flow in Annular Non-Rotating Pipe

Abstract

The flow through annulus with rotation of the inner cylinder is important, and one of its applications is with drilling of oil wells where drilling fluid flows between the drillstring and the well casing or the open hole to transport cuttings to the surface. The drilling fluids usually have non-Newtonian properties and the rheological requirements are that they should have low effective viscosity, consistent with transporting drilled cuttings back to surface, and high effective yield stress to keep solids in suspension during stationary periods ]1].

As a first step towards good understanding of flow through annulus with rotation of the inner pipe, a study of flow through the annulus of stationary pipes may became necessary, This paper amid at presenting results of a computational study of steady, compressible flow with different Reynolds numbers through a Axisymmetric geometry, then the computational results was compared with previously experimental work performed by Quarm by 1967 ]2] for the same geometry and same fluid type and parameters. In the present work the commercial CFD code Fluent v6.0.20 ]3] is used to compute the results of computational study. Computational results shows that modifying the wall function constants considering experimental values has no great effect on solution accuracy (Fig 5 and 8). Good agreement between computational and experimental results was obtained once the specified flow rates had been corrected, as shown in (Fig 11).