Flow Distribution and Pressure Drop for Parallel Flow

On the basis of subchannel analysis, a simple model to predict the flow distribution and the pressure drop for a turbulent flow through rod bundles is developed. The model is applicable to an isothermal, fully developed flow. The most significant feature of it is that the geometry factor of a turbulent flow for a subchannel is evaluated from that of a laminar flow. The proposed model is tested by the experimental data of the other investigators as well as the authors. The calculated values of the flow distribution and the pressure drop are in good agreement with the experimental data. The dissipation of energy due to wall friction in a rod bundle is discussed. The result shows that the condition of the minimum dissipation is equivalent to that of equal frictional pressure gradient in each subchannel.