[iampolaris]

Hello, every one!
As defining inlet velocity of a two-phase flow bed, in which the voidage is constant, i need to ensure that the inlet mass flux of one phase is equal to the outlet flux from the top patch. Based on the groovyBC utility, i have defined Ua(volvectorField of one phase) in the inlet boundary, as shown below. UsL and UsR are both the inlet boundary.
boundaryField
20 {
21 UsL
22 {
23 type groovyBC;
24 valueExpression "0.5*flux";
25 variables "totalArea@UsL=sum(mag(Sf()));
flux@top=sum(phia())/totalArea/ 929.5;";
26 value uniform ( 0 0 0 );
27 }
28
29 UsR
30 {
31 type groovyBC;
32 valueExpression "0.5*flux";
33 variables "totalArea@UsR=sum(mag(Sf()));
flux@top=sum(phia())/totalArea/ 929.5;";
34 value uniform ( 0 0 0 );
35 }

35 }
........
However, when i ran the case, there were errors displayed on the screen.
"
--> FOAM FATAL IO ERROR:
problem while reading header for object Ua

file: /home/zhouquan/OpenFOAM/zhouquan-1.7.1/run/tutorials/multiphase/twoPhaseEulerFoam/bed3/0/Ua at line 1.

From function regIOobject::readStream()
in file db/regIOobject/regIOobjectRead.C at line 69.
"
Who can tell me how to do with it?
Thank you!