Computational Fluid Dynamics for Irregular Pentagon Natural Circulation Loop

Abstract. Electricity is an important needs for everyday life. Nuclear Reactor is a power plant that have low CO 2 emission and the energy is available at any time. Nuclear reactor needs a passive safety system that allow it to run without external power source or any human intervention. One of the passive safety system in nuclear reactor is natural circulation. A study of irregular pentagon natural circulation loop using water as its coolant has been done previously. In this study the natural circulation loop is simulated using ANSYS Fluent. A mesh independence study is done for obtaining mesh with accurate result but at effective computational cost. After that some flow parameters is obtained, namely cold leg temperature, hot leg temperature, and the flow Reynolds number with a value of 34.29 C, 39.93 C, and 86.8-132.6 respectively. Those parameters is compared to a reference study and an error less than 3.5% are obtained. This result means that this simulation model can be used for further study.