[ehsan]

Dear All

Please see Eq. 4 in the paper below:

http://www.marinepropulsors.com/proc...0Propulsor.pdf

May I ask you whether in OpenFOAM the same equation including turbulence effects are used for viscosity of two phase flow or only simple averaging from laminar values are employed?

Best Regards

[salehda]

any news about this issue , I am using a Herschel Bulkely model and tried setting the momentum predictor On or Off and I usually get unstability in case of turniing the momentum predictor on and less gravitional effect when turninhg it off ??
this problem is becoming annoying and i had no clue about it now!!1

[cfdonline2mohsen]

Originally Posted by ehsan

Dear All

Please see Eq. 4 in the paper below:

http://www.marinepropulsors.com/proc...0Propulsor.pdf

May I ask you whether in OpenFOAM the same equation including turbulence effects are used for viscosity of two phase flow or only simple averaging from laminar values are employed?

Best Regards

Dear Ehsan,

please take a look at the interFoam solver. you will see sth like this:

surfaceScalarField muEff
(
"muEff",
twoPhaseProperties.muf()
+ fvc::interpolate(rho*turbulence->nut())
);

So OF will Consider both viscosities

Best Regards,
Mohsen

[kk415]

Hello All


I am performing a test case of static bubble where the bubble column is kept at zero gravity. The test case is from M.Hermann paper http://multiphase.asu.edu/paper/jcp_2007.pdf of density and viscosity ratio 1. Here we plot La vs Ca to evaluate the spurious current generated. He has chosen viscosity=0.1, surface tension coefficient=1 and varied the density to vary the La number and obtain Ca of the order of 1e-6.



But for interFoam I am getting Ca of the order of 1e-4 for viscosity=0.1 and Ca of the order of 1e-6 for viscosity=1 keeping value of La same. Is it possible to get a solution independent of viscosity value for this problem? How can I optimize the solution parameters?


The current solution parameters that I am using is attached here.

[vonboett]

Hello


Your Mesh is qite coarse, as the volume-of-fluid method is quite sensitive to grid resolution. you have the same high density for water and air and your solution is affected by sigma in your transportProperties dict and your simulation neglects turbulence. I suggest you look at interFOAM tutorial cases.