【摘要】 推移质输沙率是泥沙运动力学的重要内容。目前,推移质输沙率的研究大多集中于时均输沙率,对瞬时输沙率的研究则相对较少。首先,介绍了Ballio提出的均匀沙瞬时输沙率的计算方法,对其进行推导得到非均匀沙瞬时输沙率计算公式;其次,通过非均匀沙水槽试验中得到不同颗粒泥沙的瞬时运动速度,代入改进的Ballio输沙率公式中,计算得到瞬时输沙率;然后,采用定义方法计算瞬时推移质输沙率,并与Ballio方法进行比较,结果表明两种方法得到的推移质瞬时输沙率较为接近,说明采用改进的Ballio方法计算非均匀推移质瞬时输沙率是可行的。同时,通过大量试验,揭示了非均匀推移质瞬时输沙率在时间上不稳定性、在空间上不均匀性以及运动过程中间歇性等特性。更多还原

【Abstract】 Bedload discharge is an important content of sediment movement mechanics. At present thestudy of bedload sediment transport rate mostly focused on time average rate,while instantaneous sedimentrate is relatively fewer. Firstly,Ballio method for calculating uniform bedload instantaneous transport ratewas introduced,and the improved Ballio method was derived to calculate non-uniform instantaneous trans-port rate. Secondly,the instantaneous velocity of different sediment particles was measured in flume experi-ment,and substituted into the improved Ballio formula,the instantaneous transport rate can be obtained.Then definition method was used to calculate the bedload instantaneous transport rate,compared with Bal-lio method,the results of two methods is relatively close. It is feasible the improved Ballio method used tocalculate the non-uniform bedload instantaneous transport rate. Meanwhile,the characteristics of the non-uniform bedload instantaneous transport rate were revealed in this paper,such as instability on time,non-uniformity on space and the intermittency in the sediment movement process.更多还原