Analytical study on the Subchannel Pressure Loss for Turbulent Flow in Bare Rod Bundles

핵연료봉 주위에 형성되는 난류유동장에서 부수로 압력손실에 대한 해석적 연구

A theoretically based prediction for the determination of the subchannel friction factor at low pitch to the rod diameter ratio (P/D < 1.2) in the bare rod bundle flow has been developed. The present model assumes the validity of the Law of Wall over the entire flow area. The algebraic form of the Law of the Wall is integrated over the entire flow area and the local friction velocity variation along the rod periphery is considered in this study. The present method is applied to the rod bundles with P/D < 1.2, and the prediction results show good agreement with the available experimental data.