nusselt calculation in patch
 

i want to calculate the following expression


Nu=L*/(Tw-T0)d(T)/dy @y=0


how can i define d(T)/dy @y=0 at patch i in openFoam ?

follow the below link its totally helpful
http://www.cfd-online.com/Forums/ope...l?nojs=1#links

gradT.boundaryField()[patchi] =T.boundaryField()[patchi].snGrad();