Experimental Measurement of the Thermal-hydraulic Characteristics of subchannels in $6{\times}6$ rod bundles using LSVF mixing vanes

LSVF 혼합날개를 이용한 $6{\times}6$ 봉다발의 부수로에서의 열수력적 특성에 관한 실험적 측정

In present study, the thermal-hydraulic characteristics of the subchannels are investigated as measuring single-phase heat transfer coefficients and the cross sectional velocity field using LDV in the downstream of support grid in $6{\times}6$ rod bundles. Support grid with mixing vanes make enhancing heat transfer in rod bundles by generating turbulent flow. But this turbulent flow only is reserved in a short distance. Support grid with LSVF mixing vanes keep the turbulent flow a long distance. The experiments are performed at the nominal Reynolds number 30,000 and 50,000. The heat transfer coefficients are measured using heated and unheated copper sensor. In this study, the comparison of local heat transfer coefficients for LSVF mixing vane and split mixing vane is represented.