Function velocity for precursors in Loop App

[smpark7]

I am trying to simulate a ULOF scenario, by exponentially coasting down the pump with a time constant of 5sec.

I first tried using u_func, v_func, w_func to define the velocities as a function of time in PrecursorAction. I got the following error:

Variable, looped precursor advection requires that variable velocity has the values uu, vv, ww set through the controls module, NOT simply specifying functions through the precursors block.

So I tried using u_def, v_def, w_def as instructed in the PrecursorAction.C file, and using the Controls module to vary the velocities with time.

[./flowControl]  
  type = RealFunctionControl  
  parameter = '*/*/u_def'
  function = nullFunc
  execute_on = 'timestep_begin'
[../]

The main input file runs fine for the first time step. But for the "sub.i" input file that I use for the Loop App (inspired by the LOSCA and LOFA problems in Moltres), I get this error:

The desired parameter '*/*/u_def' was not located for the 'flowControl' object, it either does not exist or has not been declared as controllable.

Neither LOSCA nor LOFA apply time-varying velocities to the precursor flow, so I'm not sure how to implement this.

[smpark7]

This issue can be resolved by replacing */*/u_def with */*/uu in the control object.