Evacuation simulation in FDS6.7.6

[Agnés Durand]

Hi, I'm trying to run a simulation with FDS6.7.6-0-g5064c500c-release with to study only the evacuation of the occupants inside a stairwell. A very similar scenario I can get it to work with FDS5. I attach the txt file. In particular, humans enter the first door, but do not walk down the evss.

Anyone kindly have any suggestions regarding this?

[Agnés Durand]

[Gregor]

Can you specify your problem? Where does the problem occur? At which evss does the problem occur? With which version did your model work?

[Agnés Durand]

I'm using FDS 6.7.6.

The problem is that humans used the first door but don't use the evss. A very similar code (not  identical), with FDS5 work perfectly

[Gregor]

Can you explain your code:

&DOOR XB=-4.2,-2.6, 1.3,1.3, 0,0.2, ID='Door_in_0', IOR=-2,  EXIT_SIGN=.FALSE., TO_NODE= 'Door_out_1', XYZ=  -3.2, 1, 0.1 /

&DOOR XB=-4.2,-2.6, 1.2,1.2, 4.6,4.8,ID='Door_out_1', IOR=+2,  EXIT_SIGN=.TRUE., TO_NODE= 'Door_in_0', XYZ=-3.2, 1, 4.7 /

Why don't you use DOOR->ENTR?

[Agnés Durand]

I used door-> door like i ever use with FDS5.

I see also in the example of stairs evacuation with FDS6 that this code is correctly.  That's right?

[Gregor]

from a post by Timo:

After this, you have somewhere in you stairs a point, where the stair description ends at this floor plan and the stairs are continuing at the lower (agents are going downwards) floor plan. At this point (actually a line in a floor plan) you should put a DOOR in the upper evacuation mesh, and an ENTR at the lower floor plan. NOTE: The DOOR will put a one cell thick automatic OBST behind the line defined by the XB on the evacuation mesh, where the DOOR is (i.e., "upper evacuation mesh" ). You should keep this in mind, it your staircase is tall, i.e., it is going still upper than this "upper evacuation mesh". It might be that the XBs of your DOOR and the correponding ENTR should differ by one grid cell due to this "automatic OBST that is placed in the evacuation geometry". 

Where to put the DOOR=>ENTR: Depends on your stair geometry. If your staircase has intermediate landings, then it might be best to place the door=>entr connection at the intermediate landing (e.g., at the liine between the intermediate landing and the stair flight going down to the intermediate landing from the above floor level). This way the merging flow between the floors and agents already in the stairs is treated better (if you have more than one floor tall stairs and you have 2 floor high stairs). Note, that you could move the XYZ of your DOOR so that it is better seen in the floor, where the agents are. By default, it will be close the DOOR XB, i.e., inside the stairs close to the end of the stair flight going to intermediate landing.

Please use the search here in this group. The topic has already been asked and answered several times.

[TimoK]

Just a note: DOOR => ENTR could be also DOOR => DOOR, but DOOR=>ENTR is easier to write in the .fds file.

Another note: A DOOR with no TO_NODE set is practically same as an ENTR. So DOOR => DOOR(no to_node given) would be fine too.

Third note: DOOR=>DOOR(to_node set) is a two-way door, the agents can go up and down, but this is not working nicely, if there are

agents trying to go both directions at the same time, a traffic jam is occured really easily. And this kind of model is also calculating

the guiding flow fields for evacuation for the both doors. DOOR=>ENTR and DOOR=>DOOR(no to_node) just calculate the guiding flow

field of the "incoming door". Thus, the initialization phase is faster and no agent (accidentally) choose the "outgoing door" as its target.

NOTE: FSD 6.7.6 has a new evacuation strategy to do fire+evacuation simulation. But a fire drill (evacuation drill) mode is simple: You just add EVACUATION_INITIALIZATION=.TRUE. to the MISC-namelist (and EVACUATION_DRILL=.TRUE., if not there already). And if you want to read in the EFF file, take the initialization=T away and put there EVACUATION_MC_MODE=.TRUE. (FDS+Evac is a stochastic programme, so you should run it many times using the same input, the MC mode make it faster.)

TimoK

TimoK