Issue running Complex Stoichiometry -

[Heidy Fajardo]

Dear Dr. Floyd  and Dr. McGrattan  

I'm trying to run a combustion of n-dodecane using two models : Simple Chemistry  and Complex Stoichiometry. However, I have the following problems :  

1. For the "Simple Chemistry" (File FODR8), the MLR_DODECANE does not seems to match with the bibliography. What is the reason ? 
2. Even if I have the same product and characteristics for the Complex Stoichiometry  (File FOD3R1)  , the combustion does not occur as per the "simple chemistry". The fuel is not burning. Where is my mistake or why is that happening ? 
   

Thank in advance you for your reply

[dr_jfloyd]

1.  You are predicting the burning rate for the SURF NAPPE.  Have you looked at the Validation Guide to see how well FDS does with other cases where the burning rate of a liquid pool is being predicted?  Are you faithfully representing the conditions in the test where the burning rate was measured? Have you performed a grid study?

2. You have a high molecular weight fuel with no thermophysical properties specified.  Please review the FDS User's Guide Chapter on defining species and what it has to say about this.

[Heidy Fajardo]

Thank you for your reply, 

For the point 2. I included the thermophysical properties, but still there is no combustion. What would be the reason ?

[dr_jfloyd]

You did not specify a gas specific heat.

The enthalpy of formation of FOD gas cannot be 9000 kJ/mol if you have a heat of combustion of 43010 kJ/kg.

[Heidy Fajardo]

Thank you !

I modified the values and I took the enthalpy of formation of Dodecane.