Thermal hydraulic analysis of nuclear reactor core and its associated systems can be performed using analysis system, subchannel or computational fluid dynamics (CFD) codes to estimate the different thermal hydraulic safety margins. The safety margins and operating power limits under different conditions of the primary as well as secondary cooling system such as the system pressure, coolant inlet temperature, coolant flow rate, and thermal power and its distributions are considered as key parameters for thermal hydraulic analysis. Considering the complexity of rod bundle geometry, boiling heat transfer and different turbulent scales bring about the many challenges in performing the thermal hydraulic analysis to ensure the safe design and operation of nuclear reactor systems under normal and abnormal conditions. A comprehensive review is presented of past, present and future challenges in state-of-the-art thermal hydraulic analysis covering various aspects of experimental, analytical and computational approaches.

Fire simulation utilizing computational fluid dynamics (CFD) techniques was employed to reconstruct the aged-care facility fire incident that occurred in Quakers Hill, Sydney, in Nov 2011. Based on the sentence descriptions by the suspect and witnesses, the fire was intentionally lit on hospital beds sheets in an empty room and eventually spread to the entire building. The main objective of this simulation is to determine the fire origin and to gain insights into the fire development that resulted in three fatalities in the burn room. Preliminary numerical studies were initially performed in the model to investigate possible locations of the fire sources before the mock-up experiment was carried out in an actual size test room facility. The measured and predicted gas temperature from the thermocouple readings compared well, particularly with the peak temperature reaching approximately 900℃. Numerical simulation indicated that fire spread within the room was quickly established due to large amount of combustible materials being present and ample entrainment of air from the surroundings into the room through the window and doorway. This article illustrates the promising application of CFD for building fire modelling and simulation to provide evidences of criminal identification for fire investigation.