I was trying to simulate a fluid in a channel with one wall stationary while the other oscillating with an amplitude 'A' and time period 'T'. I wanted to average the velocity spatially as well as in time. With time average being over the following time steps t+T,t+2T,t+3T....t+nT. I looked into fix ave/spatial but it limits us by saying Nfreq must be a multiple of Nevery, hence can use it only for t=0.
I would like to know if there is a way that I could do it with in build functions in LAMMPS or do I need to edit the code.
Any help would be appreciated.
BR/Joseph
Can you reset the timestep to 0 before starting
the run in which you turn on fix ave/spatial? Then
t = 0 in your formula below.
Steve
But by resetting the time to t=0 would not that effect the oscillation of the wall.
I was using fix move for oscillating it and its position is given by X=Xo+Asin(wt).
So by changing the time I believe it would change its position and velocity as well.
BR/Joseph
You can easily write a formula that sets the osciallations
you want from any offset in t. What I suggested was
a way to make fix ave/spatial work, if I understood
the problem you were having with it.
Steve