Impact Sprinkler - HRR

[LenaAhnungslos]

Hello,
I have another question.
I tried to simulate a fire that ist controlled by a Sprinkler.
The Sprinkler affects the temperatures, they are lower, however the HRR always rises up to its maximum. Normally the Sprinkler should keep the HRR on a lower level. How can I affect the HRR ?

I hope you can help me.
Lena

[LenaAhnungslos]

Do I have to fix the HRR maximal that will reach the fire with the effect of the Sprinkler instead of the HRR of a "free" fire ?
So I have to calculate the HRR of the fire under Sprinkler control?

[Charlie Thornton]

If you are using a layered surface that has ignited, the water droplets should operate naturally on the fire. However, if you are using a burner surface (one where you set the HRR), then you also need to set the extinguishing coefficient. For more information, check out the FDS Users Guide, section 12.5: "Special topic: Suppression by Water (Mixture Fraction Model Only)".

[LenaAhnungslos]

Thank you for your help.
Now I'm a little confused because of the unities.
FDS user's guide and "my" PyroSim Edit-Surface-burner says that extinguishing_coefficient is expressed in m^2/kg/s. PyroSim Example guide 2010.2 expresses the coefficient in 1/s (page 12).
Finally, to define the extinguishing coefficient do I habe to enter the e-coefficient or the k(t) that is calculated with th e_coefficient?

[LenaAhnungslos]

I'm sorry. I found the solution. :-)
http://groups.google.com/group/fds-smv/browse_thread/thread/41af248e0e691d36