Numerical simulation of thermal stratification in an elbow branch pipe of a tee junction with and without leakage

摘要: Abstract Thermal stratification can cause thermal fatigue of the piping system a nuclear power plant. One regions most at risk suffering from is small elbow pipe branching off main coolant loop for drain or letdown in chemical and volume control (CVCS). This work focuses on fundamental description caused by turbulent penetration buoyancy effects branch using large-eddy simulations (LESs). The LES results normalized temperature, mean root-mean square (RMS) temperature were found to be good agreement with available experimental data which confirms that predict closed where cold fluids are stagnant. Subsequently, flow heat transfer numerically predicted when leakage occurred pipe. numerical show region pushed towards horizontal part may remain there long time ratio 1%. However, quickly eliminated 5%, although higher spectrum density (PSD) early stages leakage. It concluded result being high stratification.