Sprinkler definition on defined HRR ramp

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marcelo

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Aug 5, 2018, 11:10:01 AM8/5/18
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Hello everybody!
I have a fire with defined hrr ramp, and after read about the difficult to quantify reduction of the buning rate i'm trying to set up sprinkler to see how long it turns on.
I run a simple test, but i have something that i dont understand.

&SPEC ID='WATER VAPOR' /
&PART ID='my droplets', DIAMETER=1000., SPEC_ID='WATER VAPOR' /   
&PROP ID='Spk'
QUANTITY='SPRINKLER LINK TEMPERATURE'
FLOW_RATE=50
RTI=350.
ACTIVATION_TEMPERATURE=79.
OFFSET=0.10
SPRAY_ANGLE=0,51
PART_ID='my droplets'
C_FACTOR=0
PARTICLE_VELOCITY=10.
SMOKEVIEW_ID='sprinkler_upright' /  
&DEVC XYZ=2.5,2.5,4.5,ID='sp_1', PROP_ID='Spk' /

I'm triyng to set  up simple spray full cone like attached fig. 1 (90-39=51).
If i set a flow rate of 100 l/min i have a pattern similar to what i want (see attached fig. 2)
If i set a flow rate of 50 l/min i have a strange pattern (see attached fig. 3)
For the purpose of simulation, i must specify part diameter, flow rate, spray angle, particle velocity ? I would like to define how long sprinklers turns on and see that on smokeview.

Thanks everybody


fig1.PNG
fig2.PNG
fig3.PNG

dr_jfloyd

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Aug 6, 2018, 7:04:17 AM8/6/18
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If you want a solid cone 39 degrees away from the -z-axis then SPRAY_ANGLE=0,39.  The angle is with respect to the ORIENTATION of the sprinkler and has a default value of (0,0,-1). 

marcelo

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Aug 6, 2018, 7:59:17 AM8/6/18
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For the purpose of my test i must set all parameters velocity, flow rate, diameter ?
Con you suggest some value ?

Brad Casterline

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Aug 6, 2018, 8:16:39 AM8/6/18
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https://www.hsdl.org/?abstract&did=685121

Have a look at this Marcelo, if it is what i think it is-- 6 years ago or so it was easy to search for 'dave Sheppard nist velocity and diameter of fire sprinkler droplets'-- the pdf came right up. It is an excellent research project. 

Brad

On Aug 6, 2018 06:59, "marcelo" <a.sam...@gmail.com> wrote:
For the purpose of my test i must set all parameters velocity, flow rate, diameter ?
Con you suggest some value ?

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Brad Casterline

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Aug 6, 2018, 10:37:55 AM8/6/18
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The flow rate is based on Hazard Classification. 
The actual foot print of the spray pattern on the floor doesn't change that much from 60 to 240 lpm in real life. It is interesting to do a "bucket test" at the fuel surface, with AND without burning, with that burning both specified (E_COEFFICIENT), and predicted (let her rip).

marcelo

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Aug 6, 2018, 11:22:37 AM8/6/18
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Thank you so much. 
For pratical desgin purpose its right that i only evalute how long the sprinkler activate and i cant evaluate hrr redcution if i havent e_coefficent ?
My intention is to evaluate how long sprinkler activate and then have a costant hrr. 
Thanks 



Il giorno lunedì 6 agosto 2018 16:37:55 UTC+2, Brad Casterline ha scritto:
The flow rate is based on Hazard Classification. 
The actual foot print of the spray pattern on the floor doesn't change that much from 60 to 240 lpm in real life. It is interesting to do a "bucket test" at the fuel surface, with AND without burning, with that burning both specified (E_COEFFICIENT), and predicted (let her rip).
On Aug 6, 2018 7:16 AM, "Brad Casterline" <bcaste...@gmail.com> wrote:
https://www.hsdl.org/?abstract&did=685121

Have a look at this Marcelo, if it is what i think it is-- 6 years ago or so it was easy to search for 'dave Sheppard nist velocity and diameter of fire sprinkler droplets'-- the pdf came right up. It is an excellent research project. 

Brad
On Aug 6, 2018 06:59, "marcelo" <a.sam...@gmail.com> wrote:
For the purpose of my test i must set all parameters velocity, flow rate, diameter ?
Con you suggest some value ?

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