中文摘要：

提出了实验中发现的一种挖泥船管道水力输送粗砂阻力特性的新类型——多峰阻力特性，而现有理论根本无法解释这一现象。应用两层模型方法，对出现多峰阻力特性的管道水力输送粗砂实验数据进行了计算，分析了多峰阻力特性与内部流动分层结构的关系。研究表明，这种新型的多峰阻力特性的出现，是由于管道内部流动结构特性，如上下两层分界面位置、两层浓度差、速度差等，随着浆体水力输送平均速度的变化，出现了增减交替而非单调的变化。

英文摘要：

A new pattern of flow resistance, called muhi-peak flow resistance, of coarse sand hydraulically transported in a dredger pipeline is proposed. The phenomenon can not be interpreted by the existing hydraulic transport theories. By employing the two layer model, the measured resistance data of coarse sand flow with multi-peak is calculated. The relation between the multi-peak flow resistance and the internal layered-flow structure characteristic is analyzed. The study shows that the multi-peak flow resistance is due to the alternating up and down instead of monotonic change of the internal layer-flow parameters, such as the interface position, solid concentration and velocity differences between the upper layer and the lower layer, etc., under different transport velocities.