| Abstract: | An experimental investigation, covering a Reynolds number range from 1900 to 9800, was conducted to study the influence of a non-coplanar blockage on the velocity and turbulence intensity distributions in an unheated 7 X 7 rod bundle. Using the blockage sleeves from a previous 61% coplanar blockage study, the non-coplanarity was obtained by axially staggering these sleeves in a prescribed manner. The results showed that the introduction of non-coplanarity did not result in significant changes from the overall bundle flow behaviour with a coplanar blockage. The effect on the flow immediately upstream and downstream of the blockage and within the blockage was less pronounced, thereby resulting in a smaller degree of flow diversion. The blockage zone, despite being effectively longer than the coplanar geometry, did not seem to adversely influence the downstream flow recovery process. Indeed the recovery to an undisturbed flow profile was more rapidly established. Complete flow recovery was attained for both the non-coplanar and coplanar blockage geometries at the same axial location in the rod bundle. Predictions from the COBRA subchannel computer code again agreed reasonably with the experimental data. |
