Changeset 408 for trunk

Timestamp:

Nov 19, 2007, 2:45:03 PM (16 years ago)

Author:

gerson bicca

Message:

a better formulation on effectiveness equation to solve convergence problems

File:

• trunk/eml/heat_exchangers/DoublePipe.mso (modified) (1 diff)

trunk/eml/heat_exchangers/DoublePipe.mso

@@ -1435 +1435 @@
         case "counter":
 
-if Method.Cr equal 1
+if Method.Eft >= 1
         
         then
         
 "Effectiveness in Counter Flow"
-        Method.Eft = Method.NTU/(1+Method.NTU);
+        Method.Eft = 1;
         
         else
         
 "Effectiveness in Counter Flow"
-        Method.Eft = (1-exp(-Method.NTU*(1-Method.Cr)))/(1-Method.Cr*exp(-Method.NTU*(1-Method.Cr)));
-        
+        Method.NTU*(Method.Cr-1.00001) = ln(abs((Method.Eft-1.00001))) - ln(abs((Method.Cr*Method.Eft-1.00001)));
 end