Problem with fluent fluind inputs
 

Hello guys!
I am a new in this forum and also new with Fluent. I am trying to find out pressure lost in pipe annulus and for this my fluid is power low. When I am trying to enter inputs of the fluid such as Konsistency index K and n the program asks me the viscosity limits maximum and minimum. So the problem is that i dont know how to find thes limits. Actually I found by calculation but the pressure not suits with these limits. Could someone help me?:(