I will give you some guides using Darcy's formula to get abetter accuracy, these notes actualy based on the persure drop value:<br>
1-If the pressure drop (P1 - P2) is about 10% of the inlet pressure P1 then you can use Darcy's by getting fluid properties either upstream or downstream conditions.<br>
2-If (P1 - P2) is between 10% to 40% then Darcy could be used with average properties between upstream and downstream .<br>
3-If higher then there is some limitations on Darcy's formula and there is some other imperical formulas could be used but you have to advise your conditions such as if isothermal conditions could be applied.<br>
<br>
Please contact me if you need further details :<br>
e-mail : <A HREF="mailto:mmsco@go.com.jo">mmsco@go.com.jo</A><br>
regards,<br>
<br>
Khaled Muhsen <br>
<br>
<br>