Ramping
 

I am using Fire Dynamic Simulator, FDS code for modelling fire scenario. In one case I am defining mass flux of fuel, when I cross check the output, the converted velocity profile shows continous fluctuations around mean valus. Even if I am defining the mass flux for 15 sec, in that 15 sec, the velocity calculated is not remaining fix. I am unable to find out the solution, can anybody help me in this matter. Is it becasue of GRID generation. I am using COARSE grid