浅谈用空气输送斜槽输送粉状物料

空气输送斜槽在输送粉状物料方面得到广泛的应用,根据设计及现场使用情况,浅谈几点要素。     

Direct measurement of the effect of non-submerged rigid vegetation-induced flow cross-section area variations on flow force in compound channel

In this experimental work, flow force in compound channel in presence of non-submerged vegetation was obtained via direct measurement method. The direct measurement method was used to address the inefficiency of the conventional energy-based methods for measuring the force within the body of highly rough flows. On this basis, the study was performed using a specially designed flume called knife-edge flume with a length of 14 m, a width of 1.07 m, and a height of 1.05 m at a stream bed grade of 10^-3. The flow force measurements were performed directly using a load cell in absence of the common errors that were otherwise associated with velocity measurement by inserting an external body into the flow. In this study, we examined non-submerged rigid vegetation layers with five different diameters (i.e., 20, 25, 30, 40, and 50 mm), three values of crossline spacing (i.e., 6, 8, and 10 cm), five values of crossline spacing (i.e., 8, 10, 12, 15, and 20 cm), and two different arrangements (i.e., ordered and non-ordered or cruciform) at three different positions (i.e., in the floodplain, in the main channel, and simultaneously in the floodplain and the main channel) by performing a total of 451 tests. The flow force exhibited the highest sensitivity to the increase in vegetation volume under the non-ordered arrangement. In this respect, the improvement in the flow force with increasing the percent volume of vegetation was much larger when the vegetation was arranged in a non-ordered rather than ordered fashion, with the effect of the vegetation been even more pronounced in the floodplain rather than the main channel. In addition, at a certain percent change of the flow force, the trough-vegetation flow velocity was higher under the ordered arrangement rather than the non-ordered arrangement, reflecting the more difficulty encountered by the flow as it passed through the non-ordered vegetation. Based on the analysis results, it was found that the flow force would change by 060% when the vegetation had grown in the floodplain with λ* values in the range of 0–1. In cases where the vegetation had grown in the main channel and simultaneously in the main channel and the floodplain, the flow force variations increased to 10–70% and 20–80% as the λ* changed from 0 to 10, respectively. Analyzing the results of the experiments and the vegetation-modified Reynolds number, a relationship was further presented for calculating the flow force in presence of non-submerged rigid vegetation in a compound channel.     

U形渠道直壁式量水槽体型优化及在泾惠渠三支渠上的应用

本文对U形渠道直壁式量水槽的体型进行了优化,规范了量水槽的设计标准,根据优先数,对量水槽的喉道宽度进行了优选,结合泾惠渠三支渠U形渠道的实际情况,优选后的喉道宽度有5种,常用的只有3种。规定了量水槽的命名方法。为量水槽的标准化、工厂化生产奠定了基础。     

Seismism and Fluxoturbidite in Front of Delta

Seism is one of the main triggering mechanisms of forming fluxoturbidite in front of delta. The forming process of fluxoturbidite in front of delta under seismism was experimentally simulated in lab.The results show that there are two kinds of slumping and three kinds of fluxoturbidites in front of delta under seismism. The liquefied fluxoturbidite and secondary overlapped turbidite move by their own gravity, and develop mainly on the base of foreslope and the frontal bed slope. They have a small sedimentary scale and can‘t move too far. On the contrary, the faulted fluxoturbidites have a larger scale and can move a long distance. The collision- power from hinder overlapped sand body is also the motivity of the faulted fluxoturbidite‘s migration besides its own gravity. They mostly develop in the deep sag in front of delta, and are the favorable room to accumulate petroleum. Finally, according to the demonstration and inversion of similarity, at least 7.35 M of earthquake had happened in middle- Shasan period of Paleogene, which induced the slumping of delta front. So the tectonic action of northern steep slope is the main reason to induce earthquake.     

波浪作用下细颗粒泥沙密实起动试验

通过室内水槽试验，描述了波浪作用下细颗粒泥沙的起动现象。在规则波作用下，天然沙和轻质模型沙的起动试验资料表明，天然沙的干重度随淤积历时的增长而增大，且起动时的波高和起动流速随泥沙干重度的增大而增加。电木粉的干重度对起动时的波高和起动流速影响很小。     

斗槽分流冲沙原理分析

根据斗槽式取水构筑物室内模型试验结果,对全断面斗槽和设置分流墙后的水力冲沙特性进行了理论分析,说明在斗槽下游冲沙最不利流段设置分流墙后,分流段的流速要比全断面同流段流速提高一倍。分流冲沙是解决斗槽水力清淤的一种有效方法。     

冲积扇发育过程中砾石颗粒对砂坝和沟流的控制作用——基于冲积扇水槽模拟实验

通过观察和记录冲积扇自旋回沉积模拟实验,研究在冲积扇的发育过程中,砾石颗粒对冲积扇在沉积过程中的控制机理。研究表明:在同一期洪水期的中期—后期,在冲积扇扇根片流带中,沟流发育的优势方向与砾石颗粒初期分布有着重要关系,同时砾石颗粒的分布还控制着沟流改道;在冲积扇的扇中发育过程中,由于砾石颗粒是在牵引流的搬运作用下运动,因此对沟道的控制作用便更多体现在对沟道形态的改造与砂坝的形成上。通过对比冲积扇剖面中出现的多期辫流水道叠置、砂坝和沟道的分布状态,就能够验证实验过程中冲积扇表面发生的现象。在实验过程中,冲积扇形成的规模是与碎屑流的动力、携带沉积物和沉积时间呈正比关系。在碎屑流的动力与携带的沉积物相对没有变化的稳定期内,扇根的砂坝与沟流、扇中的沟道都与砾石颗粒的作用密切相关。     

渡槽抗震计算若干问题讨论与建议

基于解析与数值计算方法,详细分析、总结与讨论了《水工建筑物抗震设计规范》（修订规范征求意见稿）中渡槽抗震计算的流体晃动等效模型、渡槽的竖向地震响应及流体的TLD效应等若干问题,指出了修订规范中计算方法的不足,并提出了修改建议和算法,为渡槽抗震规范的制定及渡槽抗震研究提供了参考。     

圆弧面防波堤的水力特性研究

指出圆弧面防波堤是在半圆形防波堤基础上开发的一种新型防波堤,利用数值波浪水槽对圆弧面防波堤的水力特性进行了初步研究,同时对波浪要素及防波堤断面设计进行了分析,得出一些有益的结论。