[Nek5000-users] Time-dependant boundary condition

[nek5000-users at lists.mcs.anl.gov]

How should I impose time-dependant BC for velocity on the left vertical boundaty for a 2D box geometry.
The velocity profile should be
Vx=cos(pi*y)*cos(2*pi*t) 
Vy=0

To illustrate the idea here are the pictures.
 Instead of constant velocity Vx=c on the left (inflow) boundary of a channel
 V __________________
  |
  |
  |
  |__________________

I would impose Vx=cos(pi*y)*cos(2*pi*t) 
so for t = 0 velocity profile is
 ____________________
\   
 \ 
  \
   \_________________
for t=1 velocity profile is
    _________________
   /
  /
 /
/____________________
 
and so on.

I know it should be possible in nek5000, but still not very familiar with syntax and fortran.

Thank you in advance.