Problem with Pneumatic Conveying of flyash
 

I am trying to model pneumatic conveying of flyash.
1.) What value of granular temperature for flyash at inlet boundary condition should i chose for this calculation?
2.) What value of viscosity of flyash have you chosen for calculation? Is it equivalent to viscosity of primary phase i.e. air?

Reading material I am using does not provide this value.
First I tried to model by using default value of granular temperature (i.e. .00001) but during the iteration I got an error regarding turbulent viscosity ratio limited to 1.10^5 in XXX cell which is 0.5% of total number of cells. Then I tried to reduce the mesh size but this problem remain their. I tried other solutions provided in this forum but nothing work out.

According to Gidaspow et al. (1992), Lun et al. (1984) and Gidaspow and Huilin (1998) solid shear viscosity, solid bulk viscosity and solid pressure are all functions of granular temperature. So, is this problem is because of chosing wrong value of granular temperature at inlet??

Thanks in advance...

Regards
Shubham

Please help me guys...

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