非均匀沙床面阻力特性的实验研究

天然情况下，河流泥沙组成多为非均匀沙。河流床沙及其粒径组成的非均匀性是影响水流阻力的主要因素之一，研究床沙组成的非均匀性对水流阻力的影响，具有重要的理论和实际意义。本文在大量实验和实测资料的基础上，首次系统考虑床沙级配及其组成的非均匀性对水流阻力的影响，认识了床沙组成非均匀性对水流阻力的影响关系，初步得出非均匀性对水流阻力影响的规律，丰富了人们对床面泥沙组成非均匀性的认识，为进一步深入研究奠定了基

Experimental Studies on Bed Resistance Characteristics of Nonuniform Sediment

Under natural circumstances,the bed material of an alluvial channel is generally composed of nonuniform sediment,and its nonuniformity is one of the main factors influencing alluvial resistance.The understanding of such an influence has both theoretical and practical importance.Using one dimensional laser Doppler velocimetor flume,experiments were carried out to analyze the resistance characteristics of open channel flow with the bed sediment composed of different representative particle diameters and different nonuniformity properties.Analyses were made on the basis of laboratory test data and field measurements from other investigators.This influence was considered systematically for the first time,and relationships have been established between nonuniformity and flow resistance.