KURENAI : Kyoto University Research Information Repository

• For
A scale model can be designed by first determining the size of the model
or QR. This factor and the available power determine the velocity scale from
Eq. (50). It is important to note that the time scale will be shifted by the
factor
t=uR(56)
R •
Therefore, for a real time simulation an additional condition of
2.
tR=1 oruR=1(57)
R should be imposed. In this case, the power level can be uniquely determined
by
qoR = QR .(58)
Then one obtains
dR = dR = 1 .(59)
VI .2.4 Sample Calculations (Real Time Scale)
As an example, a simulation of natural circulation flow in a typical
light water reactor by the LOFT facility is considered. The representative
geometry of PWR relevant to the natural circulation study is shown in Fig. 2
and that of LOFT facility [8] in Fig. 3. Here the PWR geometry is that of CE
System 80. Some of the important design parameters are listed in Table I.
range of
In view of the elevation AF and AB, the axial length ratio tR is in the
R = 0.4 ti 0.44 .(60)
a real time simulation, the velocity should be reduced by the same factor
as given by Eq. (57). Then
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