[Paraview] Integrating drag and lift over time

[SanjeebPal]

Hello:

I have transient simulation results that I read into Paraview. I would 
like to calculate drag and lift at each time step. I have the normal and 
tangential wall stresses output at every time step. How do I accomplish 
this ?

For a given time step, I understand that I can use the sequence of filters

Extract Boundary surface -> Generate surface normals -> Multiply stress 
by area -> Multiply by normals -> Integrate Variables Filter

How do I get this drag and lift output written out at each time step ?

Regards,
Sanjeeb Pal