Backward facing step control with variable inlet
 

Hello,
I am a very new user to OpenFOAM, I am working on the simulation and control of incompressible flow over a backward facing step.
I have managed to run simulations of 'normal' BFS in OpenFOAM, but I would like to run the simulation in the presence of an input defined by me.

This input needs to be variable (more like random noise not sinusoidal for example), and I am not sure how to do this since I tried to use the 'UniformValue' but I think this needs for the entire input sequence to be added before the start of the simulation in a table, whereas when I apply the control the values needed to be applied would be updated at each timestep, so this would not work for me.
Has someone worked on something like this or could you point me in the right direction?

Thanks