My problem is to find a way to add some time-dependent value to wall atoms' velocity while their temperature is controlled by another fix such as fix nvt or temp/berendsen+fix nve.
In fact I want to have an oscillating heat source wall.
I tried "velocity set" command with "sum yes" keyword but the error message says that you can not add a time-dependent value. On the other hand I can not use "fix move" command because I want to control the temperature with another appropriate fix command.
Any help would be appreciated.