鄱阳湖实体动床模型设计

摘要

模型沙选择是动床模型设计的关键因素。鄱阳湖模型变率大、入湖泥沙细，动床模型宜选用轻质模型沙。本文采用泥沙运动相似条件的研究成果，进行模型沙粒径比尺的初步设计，结合水槽起动流速试验，选取适合的模型沙，并和国内几种轻质塑料沙起动流速计算公式对比，推荐了估算塑料沙起动流速的计算公式。经选取的模型沙满足起动流速相似，全沙相似条件较好，各相似比尺合理，为提高动床模型试验模拟精度奠定了基础。%The selection of model sediment is the key factor in the design of movable bed model.In view of high variable rate of Poyang Lake model and the fine sand into lake,the light model sand should be adopted in movable bed model.Combined with the flume starting velocity test,the size scale of model sand was preliminarily designed by using the research results of the similarity of sediment movement condition. The suitable model sand was selected.The incipient velocity formula of plastic model sand was proposed to estimate incipient velocity of plastic sediment,combined with several domestic lightweight formula of incipient velocity. The selected model sand meet the similarity of incipient velocity and the similar scale is reasonable.This lays a foundation for improving the simulation accuracy of movable bed model test.