Hi Lammps,

I am simulating a flow with time dependent body force. I could manage to create sinusoidal body force using

the variable and jump commands. However the temperature of the system is gradually decreasing with time.

Here is part of my input script where I do this.

variable pi equal 3.14159265

variable tp equal 1000

variable alpha equal 0.005

variable con equal 2*{pi}/{tp}

variable neq equal 200000

variable navg equal 400000

reset_timestep 0

label loop

variable t loop {neq}
variable f equal 0.05+{alpha}*sin(${con}*$t)

fix 4 flow addforce $f 0.0 0.0

run 1

unfix 4

next t

jump equil.in loop

Thanks

Srikanth