Hydrogen Injection Rate

[Abdelrazik Elfar]

Hi,

 

I am trying to input the injection rate of hydrogen very low such as 10E-14 since my model is small. But the model gets the steady state after two seconds of starting and gives no results. Is the system valid for range of values only. Also, I insert the value of enthalpy of 4E-6 at 25c for the temperature, but I am not sure that this value is valid or not. I get it from a table on google.

 

 

Kind Regards,

Abdelrazik Elfar

[Alison]

Abdelrazik,

 

You can probably avoid the model hitting state very quickly by increasing your initial time step (DELTEN) under the Analysis | Solution Controls window.

 

If you are trying to inject at a constant temperature, then you can assign a very high material density to the injection cells.  This gives the cells a very large heat capacity, and any gas that leaves those cells will have the temperature of the cells (set as the initial temperature).

 

Best Regards,

Alison

[Abdelrazik Elfar]

Hi Alison,

 

I have tried to increase the initial time step as advised but the simulation gives me an error. I am not sure why. If I increase the injection rate by magnitude of on or two, it works. but if I decreased more than power -12 it shows this error.

 

Kind Regards,

Abdelrazik Elfar

[Alison]

Abdelrazik,

 

I would turn on the print options for cell Z61, and then rerun the model.  You can then view a cell history plot of parameters at this cell at each time step.

 

If you continue to have problems, please send me your SIM file and I'll take a look at it (tech@rockware.com).

 

Best Regards,

Alison