Computing spatial averages on the fly

[makrandak]

Hello,

I am trying to compute x and z averages (imagine a statistically stationary channel flow periodic in x and z) of velocities at every timestep. I further want to do the following calculation at the end of each timestep,

u_new = u (solution at the end of the timestep) + ( u_avg_xz (calculated above and a function of y) - u_avg(y) );

"u_new" becomes the new solution, "u_avg(y)" is some analytical function I can evaluate. I am thinking of using the limiter kernel in k-tau implementation for this. But I am stuck at getting the "u_avg_xz (calculated above and a function of y)" on the fly on GLL points/nodes to do the above calculation.

I was looking at the tavg.cpp plugin (I am assuming they are running time averages), and I am wondering if I can use those kernels (modifying them) to do the averaging calculation I want.
If there is any documentation available for doing such averages I would be very grateful if you point me to it.

With sincere appreciation for your help,
Makrand

[stgeke]

Look for planarAvg e.g. in the gabls1 example.

[makrandak]

Hello,

I am looking into planarAvg; thanks for the help.

Is there an example where the entire spatial average (in all directions is computed)? I want to subtract the average of a field at every timestep from itself after every timestep.

Thank you for your time and help.

With sincere regards,
Makrand