TY - JOUR
TI - Experimental approach to investigate the dynamics of mixing coolant flow in complex geometry using PIV and PLIF techniques
AU - Hutli Ezddin
AU - Gottlasz Valer
AU - Tar Dániel
AU - Ezsol Gyorgy
AU - Baranyai Gabor
JN - Thermal Science
PY - 2015
VL - 19
IS - 3
SP - 989
EP - 1004
PT - Article
AB - The aim of this work is to investigate experimentally the increase of mixing  phenomenon in a coolant flow in order to improve the heat transfer, the  economical operation and the structural integrity of Light Water  Reactors-Pressurized Water Reactors (LWRs-PWRs). Thus the parameters related  to the heat transfer process in the system will be investigated. Data from a  set of experiments, obtained by using high precision measurement techniques,  Particle Image Velocimetry and Planar Laser-Induced Fluorescence (PIV and  PLIF, respectively) are to improve the basic understanding of turbulent  mixing phenomenon and to provide data for CFD code validation. The coolant  mixing phenomenon in the head part of a fuel assembly which includes spacer  grids has been investigated (the fuel simulator has half-length of a VVER 440  reactor fuel). The two-dimensional velocity vector and temperature fields in  the area of interest are obtained by PIV and PLIF technique, respectively.  The measurements of the turbulent flow in the regular tube channel around the  thermocouple proved that there is rotation and asymmetry in the coolant flow  caused by the mixing grid and the geometrical asymmetry of the fuel bundle.  Both PIV and PLIF results showed that at the level of the core exit  thermocouple the coolant is homogeneous. The discrepancies that could exist  between the outlet average temperature of the coolant and the temperature at  in-core thermocouple were clarified. Results of the applied techniques showed  that both of them can be used as good provider for data base and to validate  CFD results.