[sagar_saroha]

I have been using:

pisoFoam -postProcess -func "grad(U)"

and it works well... but when i try using:

pisoFoam -postProcess -func "grad(UMean)"

for calculating mean velocity gradient - it show the following error


--> FOAM Warning : functionObjects::grad grad(UMean) cannot find required object UMean of type volScalarField
--> FOAM Warning : functionObjects::grad grad(UMean) cannot find required object UMean of type surfaceScalarField
--> FOAM Warning : functionObjects::grad grad(UMean) cannot find required object UMean of type volVectorField
--> FOAM Warning : functionObjects::grad grad(UMean) cannot find required object UMean of type surfaceVectorField
--> FOAM Warning : functionObjects::grad grad(UMean) failed to execute.

Please help me identify the mistake or suggest an alternate way to calculate gradient of mean velocity.