弯管中流体在简谐摇摆条件下的附加力模型分析

为了给浮动式核动力平台给水泵或凝水泵在海洋条件下的稳定运行提供计算依据，对弯管中流体在简谐海洋条件下所受附加力的模型进行了理论推导，根据模型推导结果对凝水泵入口管道中的一段弯管进行计算，并与直管中流体的附加力模型计算结果进行了对比。研究表明，直管与弯管模型计算的附加压降的差异幅度很小，差值随时间为周期性变化；摇摆周期越大，摇摆角度越小，弯管与直管的附加压降差别越小；在一般的工程计算中可将弯管近似为直管，从而简化计算。

The model analysis of the additional force of fluid in a bend under the condition of simple harmonic sway

In order to provide calculation basis for the stable operation of the feed pump or condensate pump of the floating nuclear power platform under the ocean condition, cyclical change of additional force generated by fluid in the pipeline under simple harmonic ocean conditions is derived, and a section of pipe bend in the condensate pump inlet pipe is calculated according to the results of model derivation and compared with the calculation results of the fluid additional force model in the straight pipe. The results show that the difference of pressure drop between straight pipe and bend pipe is small, and the difference changes periodically. The larger the swing period and the smaller the swing Angle, the smaller the difference of pressure drop between the bend and the straight pipe. In the general engineering calculation, the bending pipe can be approximated to the straight pipe, so as to simplify the calculation.