Upper layer temperature is the same for various mechanical flow rates.

atwhaley / cfast

Automatically exported from code.google.com/p/cfast

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What steps will reproduce the problem?
1.   One compartment (7.92mW x11.46mD x4.48mH); the walls, floor, ceiling are 
all concrete.

2.   No horizon flow vent and no vertical vent.  One mechanical flow vent (from 
outside to compartment 1), with various flow rates, e.g., 0.0 m3/sec, 0.1 
m3/sec, 0.236 m3/sec, 0.493 m3/sec, and 5.0 m3/sec.

3.   One fire object; the growth time is 300 sec., the maximal Q is 9690 kW.

What is the expected output? What do you see instead?

The upper layer temperature as a function of time should be different for 
different mechnical flow rate.  But it turns out the temperature is the same 
for the aforementioned various mechanical flow rates.

What version of the product are you using? On what operating system?

CFAST v6.2.0, Window 7.

Please provide any additional information below.

Original issue reported on code.google.com by m...@llnl.gov on 22 Apr 2014 at 7:03

Attachments:

[Mechanical flow question .docx](https://storage.googleapis.com/google-code-attachments/cfast/issue-113/comment-0/Mechanical flow question .docx)

With no normal vents to relieve the pressure, the compartment nearly instantly go to a very high pressure. Which causes the mechanical ventilation system to shutdown (default is for the system to stop flow when pressure in compartment reaches 300 Pa. With the fire specified, the pressure reaches nearly 50000 Pa, hopefully a non-physical result for an actual space. Thus, there is no real difference regardless of the flowrate specified. The solution would be to include appropriate leakage or other ventilation so that pressure did not build to unrealistic levels.

atwhaley / cfast

Upper layer temperature is the same for various mechanical flow rates. #113