I a performing a simulation of oscillating plate in a channel with fluid. I am trying to spatially average as well as make an ensemble average of velocities at time= T & 2T where T is the time period of oscillation of the wall. In order to check if averaging is performed as per my intentions I tried it into 2 ways once by dumping all velocity values and then averaging at time T & 2T manually i.e. (v(T)+v(2T))/2. And then using fix ave spatial to average it(find the portion of the code used at the end). But in the 2 ways I am not getting exact match of values even though I performing the averages in the same simulation. Is this because of rounding errors or am I doing something wrong.
Any help would be appreciated.
fix 8 upper move wiggle 4.0 0.0 0.0 80.0 units box
fix 9 flow ave/spatial 1 25 2000 x center 11.95 z center 1204.14 y 54.4 0.25 vx region fix_fluid file vel_fb_1.profile units box
fix 5 flow ave/spatial 40000 2 1680000 x center 11.95 z center 1204.14 y 54.4 0.25 vx region fix_fluid file vel_fb.profile units box