Safe and effective loading of nuclear reactor fuel assemblies demand qualitative and quantitaive analysis of the relations between the coolant temperature in the fuel assembly outlet, measured by a thermocouple, and the mean temperature of the coolant in the thermocouple plane position. In the laboratory at the Institute of Thermal Power Engineering of the Slovak University of Technology in Bratislava, an experiemental physical fuel assembly model of the VVER 440 nuclear power plant with V 213 nuclear reactors was installed The aim of the measurements on the physical model was to analyze the temperature and velocity profiles in the fuel assembly outlet. The following article deals with the analyses of these measurements based on different mass flow of the water through a physical model of the fuel assembly outlet. The following arficle deals with the analysis of these measurements based on different discontinuity generated by cold water flowing through triplet tubes and central tube in plane 1, and the positioning of the mixing CFD grid simulations of a fuel assembly outlet. All analyses were validated by means of measurements on the physical model of the fuel assembly. and Obsahuje seznam literatury
Dams have an important role in the industrial development of countries. Irrespective of the reason for dam break, the flood can cause devastating disasters with loss of life and property especially in densely populated areas. In this study, the effects of the vegetation on the flood wave propagation in case of dam break were investigated experimentally by using the distorted physical model of Ürkmez Dam. The horizontal and vertical scales of the distorted physical model are 1/150 and 1/30, respectively. The dam break scenarios were achieved by means of a gate of rectangular and triangular shape. The results obtained from experiments performed with vegetation were compared and interpreted with those obtained from experiments at which the vegetation configuration was absent. The analysis of the experimental data showed that the presence of vegetation causes a significant decrease in water depths as the flood wave propagates to the downstream and greatly reduces its impact on the settlements. It is also revealed that dam break shape plays an important role in temporal variation of flood wave.