速度落差

In this thesis, I summarize the theoretical calculation method, applied scope and notice of siphonic drainage system, and point out the advantage of siphonic drainage system compared with gravitation drainage system. In the archetype experiment study of siphonic drainage tube, I adopt different tube diameter and different structural height to survey the drainage volume and press in different place. I observe various kinds of flow state, and get chief factors which influence hydraulic peculiarity of system as the tube diameter or structural height, and find out the relevance of factor to flux. I apply CFD Fluent software and adopt standard k-ε model and RNG k-ε model, then use finite volume method and second-order upwind scheme to discrete numerical model, while coupling numeration of velocity field and press is based on SIMPLE. In the numerical simulation of curved part of tube, siphonic drainage tube experiment system and multi-outlet siphonic drainage system, I make research on internal velocity and press of system in different project condition by changing the tube diameter of curved part, negative press value in tube export and improving the quantity of water gutter. This thesis first adopts a method of combining archetype experiment and numerical simulation to study the siphonic drainage system, test and verify the validity of experiment and numerical simulation, and makefurther study on system, it solves the problems of limited testing conditions, and has a logical results, it can provide a valid method for optimizing and designing the drainage tube-net system. The conclusion have referring value for study and design of siphonic drainage system.

本文首先对虹吸式排水系统理论计算方法、适用范围以及注意事项做出总结，并分析了虹吸式排水系统的优势；再对虹吸式排水管道进行原型试验研究，采用不同管径不同立管高度，对系统流量、管道压强进行量测，观察了各种工况下的流态，对其水力特性进行研究分析，找出影响水力特性的落差、管径主要因素以及与排水量的关系；进一步应用计算流体力学Fluent软件，采用标准κ-ε模型与RNGκ-ε模型，计算过程应用有限体积法和二阶迎风格式对数值模型进行离散，速度和压力的耦合采用SIMPLE算法，分别对系统弯管段、虹吸排水管道试验系统、多斗虹吸式排水系统进行数值模拟分析，通过改变管段弯头处半径、管段出口负压值、增加雨水斗数对不同工况下系统内部的速度和压力进行研究；本文首次采用结合原型试验与数值模拟相结合的方法，对虹吸式屋面雨水排水系统进行研究，试验与模拟相互验证，并进行拓展，很好地解决了虹吸式屋面雨水排水系统由于试验条件限制问题，结果正确合理，为排水管网系统设计和优化研究提供了有效的方法，对工程设计有较好的参考价值。

150HP-300HP screw air compressor rotor is the German GHH-RAND joint shaft type unit,adopts the third generation asymmetrical dentate 5:6 rotors,The major axis is more reasonable than the choice, the tangent speed of rotors is only 30-36m/s, is far lower than that———60m/s of common air compressors, it keeps 0.003INCH between rotors that will not abrase forever, the space between teeth dropping variance is small, so the backflow loses is slight, Enhances10-12% kf the efficiency compared to the 4:6 dentate, save power 20%, adopts the Swden SKF bearing.

150HP-300HP）螺杆机转子为德国GHH-RAND联轴式机组，采用第三代非对称齿型为5：6的转子，长径比选择合理，其转子的切线速度仅为30'36m/s，远低于一般空压机60m/s 的切线速度，转子之间保持0.003INCH间隙永不磨损，齿间落差小，故回流损失小，比4：6齿型提高效率10-12%，省电20%，采用瑞典SKF轴承，极大延长了主机的寿命。

Br/br/Adopts the GHH-RAND remarkable mainfrane br/(150HP-300HP) screw air compressor rotor is the German GHH-RAND joint shaft type unit,adopts the third generation asymmetrical dentate 5:6 rotors,The major axis is more reasonable than the choice, the tangent speed of rotors is only 30-36m/s, is far lower than that60m/s of common air compressors, it keeps 0.003INCH between rotors that will not abrase forever, the space between teeth dropping variance is small, so the backflow loses is slight, Enhances10-12 kf the efficiency compared to the 4:6 dentate, save power 20, adopts the Swden SKF bearing.

采用GHH-RAND卓越主机br/（150HP-300HP）螺杆机转子为德国GHH-RAND联轴式机组，采用第三代非对称齿型为5：6的转子，长径比选择合理，其转子的切线速度仅为3036m/s，远低于一般空压机60m/s 的切线速度，转子之间保持0.003INCH间隙永不磨损，齿间落差小，故回流损失小，比4：6齿型提高效率10-12，省电20，采用瑞典SKF轴承，极大延长了主机的寿命。

A few contain gap jumps, but thebest use steep berms and smooth rollers to build speed and create smiles.

但最好使用高低起伏和几个包含间距小落差来生成速度和制造乐趣。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。