| Summary: | The WOSUB-codes are spin-offs and extensions of the
MATTEO-code [1]. The series of three reports describe WOSUB-I
and WOSUB-II in their respective status as of July 31, 1977.
This report is the first in a series of three, the
second of which contains the user's manual [2] and the third
[3] summarizes the assessment and comparison with experimental
data and various other subchannel codes.
The present report introduces the drift-flux and vapor
diffusion models employed by the code, discusses the solution
method and reviews the constitutive equations presently built
into the code. Wherever applicable, possible exteriors of the
models are indicated especially with due regard of the findings
presented in [3].
Overall, the review of the model and the package of
constitutive equations demonstrate that WOSUB-I and II
constitute true alternatives for BWR bundle and PWR test bundle
calculations as compared to the commonly applied COBRA-IIIC,
and COBRA-IIIC/MIT codes which were primarily designed for PWR
subchannel and core calculations, respectively. In fact, the
incorporation of the drift flux and the vapor diffusion pro-
cesses into a subchannel code has to be cdnsidered.a major step
towards a more basic understanding and a well balanced engineer-
ing approach without the extra burden of a true two-fluid two-
phase model.
Recommendations for improvements in the various areas
are indicated and should serve as guidelines for future develop-
ment of this code which in light of the encouraging results pre-
sented in [3] seems to be highly warranted.
The WOSUB-code is still in the stage of evolutionary
development. In this context, the review reflects the achieve-
ments as of July 1977.
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