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Code Manual for CONTAIN 2.0 - Federation of American Scientists

Code Manual for CONTAIN 2.0 - Federation of American Scientists

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Table 14-1<br />

Types <strong>of</strong> Bums Allowed <strong>for</strong> Different Ignition Sources<br />

I<br />

Type <strong>of</strong> Bum<br />

Ignition Criteria I Deflagration I Diffusion Flames I BSR<br />

Igniters, or equivalent x Xb<br />

ignition source’<br />

Cell<br />

Gas Temperaturec<br />

I<br />

Upstream Cell x x<br />

Gas Temperaturee<br />

x Xd<br />

Debris Loadingf x x<br />

Pro~azationg x<br />

‘Assumedoperatingin thetimewindowboundedbyTACTIVandTDEACT<strong>for</strong>thebumcell<br />

bAllowed<strong>for</strong> flowin unsubmergedgasflowpathsonlyif the gasinflowtemperatureexceeds<br />

DFI’EMP<br />

ThresholdgivenbySRTEMP<br />

!13SRbased on gas temperaturenotallowedduringa deflagrationtopreventa spurious transition<br />

from a deflagration to BSR<br />

‘Threshold given by DFAUTO outside <strong>of</strong> the time window, <strong>for</strong> unsubmerged gas inflow into the<br />

downstream cell that is not from an external source<br />

Debris concentration > DEBCONC; debris temperature> DEBTEMP<br />

‘Propagation from a deflagrating cell through a flow path occurs after a time delay controlled by<br />

KPROP, provided the conditions in the propagation cell are suitable; namely, the flame velocity is<br />

sufficient to overcome the flow velocity from the propagation cell to the deflagrating cell, and the flow<br />

is not submerged in either cell.<br />

The H-BURN input block is required to enable the modeling <strong>of</strong> deflagrations. In addition, the<br />

CONTBURN input block is required to model continuous burning processes like diffusion flames<br />

and BSR. Three types <strong>of</strong> inflow are modeled with respect to diffusion flames: (1) flow from each<br />

gas flow path that is not scrubbed by the pool in the inflow cell, (2) the collective gas flow from all<br />

gas paths venting under the pool surface at the inflow cell, as modified by the equilibration or partial<br />

equilibration <strong>of</strong> the gas with the pool, and (3) the (positive) mass sources to the cell, considered<br />

collectively. Each type <strong>of</strong> inflow is treated independently with respect to diffusion flame burning.<br />

For example, one diffusion flame in a cell is not allowed to ignite another diffusion flame, in the<br />

absence <strong>of</strong> all other potential ignition sources.<br />

Rev. O 14-98 6/30/97

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