Experimental study on the effect of spacer grid in two-phase flow through 1x3 rod bundle
Open Access
Author:
Green, Chad R
Graduate Program:
Nuclear Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
None
Committee Members:
Seungjin Kim, Thesis Advisor/Co-Advisor
Keywords:
air-water two-phase rod bundle spacer grid conductivity probe coalescence breakup
Abstract:
This study investigates the effects of a spacer grid on the transport of two-phase
flow parameters in an air-water two-phase flow test facility. The test facility consists of a
1x3 rod bundle scaled based on the four-loop Pressurized Water Reactor (PWR). First, a
flow visualization study is performed for flow conditions before the spacer grid, at the
spacer grid, and after the spacer grid in order to understand the effect of the spacer grid on
the flow regime boundary. Secondly, the local two-phase flow parameters are measured
before and after the spacer grid by the four-sensor conductivity probe for six different flow
conditions within the bubbly and the slug flow regimes. Both the flow visualizations and
local two-phase flow data suggest that the spacer grid has a significant impact on the two-phase flow structure and is responsible for both the coalescence and breakup of the void
structure, depending on the flow condition.
