Resistance heads in pipes under conditions of local resistances interference. Approach to experimental globalization

The hydraulic loop of the nuclear power plant has the complicated spatial layout. The local hydraulic resistances (LHR) are located, as a rule, at the relatively short distances to each other. As a result of this, during the plant operation the resistance heads of a pressure along the loop can considerably differ from the designed ones. The main reason of this is a lack of the practical recommendations on the calculation of the LHR interference on the total resistance heads. The development of the recommendations, in the authors opinions, is an important factor for the increasing of the designed hydraulic codes accuracy. The method of globalization of the experimental data on the resistance heads in the channel having two adjoined LHR, for the variant with several LHR in the loop section is described below. The method is based on the using of the experimental functions of interference of two LHR and the notion of effective LHR of the system having several LHR. This method is aimed at the reducing of the experimental information volume required for the enhancement of the accuracy of the loop hydraulic calculations. The experimental data are obtained for 17 systems having two and more LHR in the form of the rectangular projections and the grids located close to each other in the section of the rectangular cross section channel. On the base of these data the interference functions for the systems