FLOW AROUND A CYLINDER - istiarto

5.3.3 Calibration results
– 5.6 –
The computed flows with different values of the bed equivalent-roughness and the flow
depth are depicted in Fig. 5.2. Shown are the computed distributions of the velocity, eddy
viscosity, and the shear stress. The corresponding measured data are also plotted in the
same figures. Presented in the first figures (Fig. 5.2a-f) are the computed values obtained
for Yulistiyanto data and in the second figures (Fig. 5.2g-l) are those for the present
measurements. Note that for the eddy viscosity and the shear stress, different expressions
were applied to the computed and measured values. For the computed ones, the following
relations were used:
k
�� t�
� c
computed �
2
� , with c� � 0.09 is the model constant, and
�� zx ��
� �
���u
�w
computed t �
��
���z
�x ��
(5.1)
where k, �, and the velocity gradients (computed by using finite volume techniques) are
directly obtained from the mathematical model. For the measured data, the corresponding
values were obtained by:
�� t�
�
measured
��zx ��
� �u �� w ��
measured
�u ��w
�� �u �� ��
�
�u �z � �w �x w
, since �w �x