# Discussion Forum

## Cement flowing around funky 3D shape and displacing mud

 Topics: 4.3, CFD, Fluid Flow, Physics
RSS feed   |   Turn on email notifications   |   2 Replies   Last post: February 3, 2013 11:11pm UTC

John Lovell

December 12, 2012 6:22pm UTC

Cement flowing around funky 3D shape and displacing mud

Hi, I have an interesting fluids problem. 3D object in a snug fit inside a water filled tube. Pump heavy cement in one end, will it displace all of the water as it flows around the object or leave some trapped fluid.

Any recomendations on a CFD module to use?

Regards, John

David Kan
COMSOL Employee
USA

December 19, 2012 6:19pm UTC in response to John Lovell

Re: Cement flowing around funky 3D shape and displacing mud

Hi John,

I heard back from one of our in-house experts and here are some snippets:

> This sounds difficult. The implementation would need a two-phase flow, where one of the phases (cement) is a non-newtonian fluid. Whether to use level-set, phase-field or euler-euler is not clear to me. Which thixotropy model to use for the concrete is also a research area.

How well the COMSOL solvers are suited for this task is also unknown. But you can give it a try!

David

John Lovell

February 3, 2013 11:11pm UTC in response to David Kan

Re: Cement flowing around funky 3D shape and displacing mud

Hi, I found some empirical information that may significantly simplify the problem. for a first order approximation: if the flow is turbulent then the cement slurry will displace the drilling mud. So the problem becomes one of 3D flow to identify whether any zones around the object will have only laminar flow,

What I think would then be valid is to assume turbulent flow, solve with k-e, find the lowest Reynolds number, and check that the Re is large enough that the turbulent assumption is valid. Do you agree?

Regards, John

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