CFD Online Discussion Forums - Flow meter Design

CFD and Mechanical Analysis applied in Flow meter design

The fluid flow analysis software, STAR-CD from the CD adapco Group has recently been used by Schlumberger Industries, the Montrouge Technology Center to make calculations for flow meter design.

Fluid-mechanism interactions occur in a wide range of flow meter categories including turbine and positive displacement systems. Computational methods are used for calculating the dynamic interaction between moving parts and the flow in a flow meter system. Two methods can be used, one with an explicit integration of the equations of motion of the mechanism and the other with implicit integration. The advances in mesh technology including deforming meshes with non-conformal sliding interfaces opens up this new field of application for Computational Fluid Dynamics and mechanical analysis in flow design.

CFD and mechanical analysis has previously been applied to several flow meters groups for the measurement of fluid flow in closed conduits. In the recent study, CFD and mechanical analysis was applied in the study of transient fluid structure interaction for measuring elements or flow control devices comprising moving parts. The principles developed were general and could be extended to include small or large internal deformations of the moving components. Applications were made for the case of a turbine meter and an oscillating piston meter, a meter belonging to the positive displacement group.

The study illustrated that the explicit treatment of fluid rigid-body interaction in unsteady flows can be validated for a highly viscuous flow and a non-viscuous flow, both of which have known solutions. When treating stiff systems, numerical difficulties with the explicit method can be expected and the implementation of an implicit approach is therefore imposed for certain problems. A successful implicit implementation was also carried out with a case of piston movement in a tube. This necessitated several repetitions of the same step with new values of mesh displacement and boundary conditions. Application of the implicit approach demonstrated a positive displacement type of flow meter, namely an oscillating piston flow meter.

STAR-CD was successfully used in this type of application and is also an effective tool for other applications including polymer flows, stirred mixing vessels, porous media flow including filters, chemical reactors and heat and mass transfer.

Mr Driss Abouri, and Dr Andrew Parry SCHLUMBERGER Industries, Montrouge Technology Center

For more information on the CD adapco Group and its products and services, please visit the website at www.cd.co.uk