[manuc]

Dear Foamers

I have two patches (w_l,w_lb --> both of them of different area and mesh distribution) and I want to find combined nusselt No. for them.
When I do the below it crashes:
--------------------------------------------------------------
Test234
{
type patchExpression;
patches (
w_l
w_lb
);
verbose true;
variables (
"Tsat=300;"
"lc2D=0.0786;"
"sumHere{w_l}=sum(snGrad(T)*area()/(T-Tsat);"
/*"dtwl{w_l}=T-Tsat;"
"dtwlb{w_lb}=T-Tsat;"*/
"sumThere{w_lb}=sum(snGrad(T)*area()/(T-Tsat));"
"areaHere{w_l}=sum(area());"
"areaThere{w_lb}=sum(area());"
"totalAverage=(sumHere+sumThere)/(areaHere+areaThere);"*/

);
expression "totalAverage";
accumulations (
max
min
average
sum
);

------------------------------------------------------------------
But when I try to debug and remove the division by (T-Tsat) it runs ,but not what I need..

----------------------------------------------------------------------------
Test234
{
type patchExpression;
patches (
w_l
w_lb
);
verbose true;
variables (
"Tsat=300;"
"lc2D=0.0786;"
"sumHere{w_l}=sum(snGrad(T)*area());"
/*"dtwl{w_l}=T-Tsat;"
"dtwlb{w_lb}=T-Tsat;"*/
"sumThere{w_lb}=sum(snGrad(T)*area());"
"areaHere{w_l}=sum(area());"
"areaThere{w_lb}=sum(area());"
"totalAverage=(sumHere+sumThere)/(areaHere+areaThere);"*/

);
expression "totalAverage";
accumulations (
max
min
average
sum
);

-----------------------------------------------------------------

Also it creates 2 output files w_l and w_lb .Is this expected

Please note : The same was tested for a "single patch" by doing the nusslet number calculation in "expression() " as in
http://www.cfd-online.com/Forums/ope...swak4foam.html

which works finr
-----------------------------------------------------------------------------
Could you please comment on it..

My scenario: A wall cut into two patches so that I could use one of the as inlet for flow if needed.At present both considered as wall. So I want Nusselt number at the whole wall and I need averaging over both patches.