Calculation of Reynolds number
 

Hi friends,

I am doing cfd simulation for two phase flow (water and air. Have anyone idea how to calculate reynolds number for such systme and define turbulence parameter for that?

Thanks

Abid

Re: Calculation of Reynolds number
 

I think there are many approaches to Re definition for two phase flows. Cavallini at al. introduce Re numbers separately for gas and liquid. For example,they define liquid ReL in channel as follows:

ReL = 4*G*(1-x)*delta/((1-epsilon)*MuL)

where

G - total mass velocity of liquid and gas [kg/(m^2 s)] x - gas quality [kg/kg] epsilon - void fraction of gas [ m^3/m^3 ] delta - liquid film thickness of annular ring, [m] MuL - liquid dynamic viscosity [N s/m^2]

Details see in J.R.Thome, J.El Hajal, A. Cavallini, Condensation in horizontal tubes, part 2: new heat transfer modeel based on flow regimes// Int. Journal of Heat and Mass Transfer, v. 46 (2003), pp. 3365-3387.

Best regards.

Alexey.