Code Manual for CONTAIN 2.0 - Federation of American Scientists

With nondefault forced convection modeling, it should be noted that structure input order could be
important because the trapping model uses the calculated forced convection velocity across the inner
face of the first two structures in the TOF/KU trapping model, as described in Section 6.3. The
velocities for the frosttwo structures are the VIand Vzparameters in the trapping model described in
that section. If there are no structures in the cell, then the TOF/KU trapping model will be bypassed
and the GFI’ trapping rate will be used. If only one structure is in the cell, then the trapping model
will use the velocity for the fmt structure for both impacts considered by the TOF/KU model.
14.3.1.4 Convection and Condensation. This block activates condensation and evaporation of
coolant from all surfaces (structure, lower cell, and engineered system) for the entire cell. In contrast
to previous code versions, in the absence of the CONDENSE keyword for a cell, the treatment of
heat transfer for surfaces within the cell of definition is not downgraded to the simplified treatments
previously associated with dry heat transfer. All options associated with CONDENSE are available
without CONDENSE, including the Grashof number changes, enhanced output, and user flexibility
options; without CONDENSE, the Sherwood number N~~for mass number transfer is simply set to
zero, regardless of other input. Otherwise all other options previously associated with the
CONDENSE option are available. The heat transfer options previously associated with dry heat
transfer, such HCOEF, are presently reserved for structure surfaces that are not in the cell of
definition. These include the outer surfaces of structures that are exposed to the gas in some other
cell or given an external boundary condition.
The FORCED forced convection table options previously available with the CONDENSE input
block have been combined with the table options previously available with the BCINNER and
BCOUTER blocks of each structure. Tables for forced convection velocity, Reynold’s number, and
forced-convection Nusselt number (i.e., VELOCITY, REY-NUM, and NUS-NUM tables) are now
available in the latter blocks. (The NUS-NUM table has been given the new name NUS-FORC for
clarity, although NUS-NUM is also accepted.)
The new keyword MINDEPTH (discussed in Section 14.3.1.3) also supersedes FLMAX and allows
the user to set the minimum film depth for structures in the cell; any excess condensate will either
drain to a pool or be lost from the problem. The destination pool can be specified through the cell
OVERFLOW option discussed in Section 14.3.1.12.
***** ***** ***** ***** ***** ************************************************
CONDENSE
***** ***** ***** ***** ***** ************************************************
CONDENSE the keyword to enable condensation heat transfer on all surfaces but those of
aerosols in the cell. In the absence of CONDENSE, the Sherwood number
for mass transfer will be set to zero, but all other modeling options will be
available.
Rev O 14-93 6/30/97