How to Calculate Reynold's No
 

Dear all,
I am trying to calculate Reynold's no of the fluid. Is it possible to calculate? please tell me how?.

Moreover, i am also trying to calculate the Nusselt no by Reports -> surface intetgral->wall fluxes-> surface nusselt no. The CFD value is quite higher than the Experimental value. Kindly suggest me how to find in a corrective way. Thanks.