Ansys Learning Forum Forums Discuss Simulation Fluids Error in spray evaporation calculation due to temperature overflow, Forte Reply To: Error in spray evaporation calculation due to temperature overflow, Forte

jcooper
Ansys Employee

 

Hi:

Yes, Hydrogen combustion is very fast, so simulations are often numerically difficult. 

Hydrogen is a liquid only at very cold temperatures or high pressures, so injecting it under other conditions will cause instantaneous evaporation. Under these (near-liquid conditions) vaporized H2 behaves as a real gas, so density and Cp  change very rapidly with increasing temperature.  This is most likely the cause of the tiny timesteps.

I would check and see if H2 can actually be in a liquid state at the temperature and pressures of the injection.