Evaluation of pressure losses at inlet and outlet regions of 55 rods fuel assembly

Single phase pressure loss models for inlet (upstream of grid to lower portion of rod bundle) and outlet (head pipe to exit flow hole) regions of 55-rods fuel assembly have been developed. First, component geometry has been simplified by considering flow path shape, flow area, hydraulic diameter, and inlet shape affecting flow characteristics. Secondly, information of pressure loss correlations obtained from the open literature have been applied to the simplified geometry. Finally, a total pressure loss coefficient of the component has been acquired as an additive form. Pressure loss models for the grid and the exit flow hole have been compared with the measured data and an independently approached model, respectively. The effects of Reynolds number on the pressure loss coefficient have been discussed