Is there a simple way to predict turbulence in a dilute suspension of spherical particles (say ~ 10% w/v) which are travelling in a tube under very high pressures (> 8000 psi) but low flow rates (ca. 3-4 mL/min)? Is it possible to predict (just an estimate) Reynolds number if we know the particle diameter, tube diameter, and viscosity of the continuous medium rather than the suspension itself?
Thanks.
Try Elmer GUI. This open source FEM software should be able to make fairly accurate predictions of your system. High pressures alone should not change the behavior of incompressible liquids. It's the pressure differentials that drive the flow rate that dictate the fluid behavior. High differentials implies high flow or high viscosity. Low pressure differentials will have low flows even at low viscosity no matter what the absolute pressure is.
Ron, Thanks and new year greetings. The software you suggested is quite involved and perhaps requires modelling which is not my area of expertise. I was wondering if there is a Reynolds number for a "suspension" or any other measure. Does the presence of particles lower the threshold for onset of turbulence in the continuous medium and in the suspension itself?
Check out this article.
http://rspa.royalsocietypublishing.org/content/early/2009/12/11/rspa.2009.0445
Elmer does have a bit of a learning curve but it's a great program. If you are interested in modeling fluid flow at some point in the future, you may also want to check out OpenFOAM as well.
It is not clear if you are conducting experiments or determining through software. If it is through experiments, determine pressure drop. Estimate friction factor. Using Moody Chart, you can determine whether the flow is in turbulence. The turbulence is suppressed due to suspended particles. To determine the onset of turbulence in your case, conduct experiments at higher Reynolds number than the conventional value with single phase fluid. The value of Reynolds number where the friction factor lies on the Blasius line can be the critical value for turbulence.
Well, the process described in the question is highly empirical. This process is used in packing stainless steel columns with few micron spheres (packed bed) by pressure filtering a suspension under extremely high pressures. The packed bed is used in chromatography. Making a "good" packed bed of spheres is rather an art with many hit and trials other separation bands are not Gaussian. It is said that turbulence should be avoided during the column packing process.
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