离散过程

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。

After created qualified grids, discretized physical characteristic, we computed the temperature and velocity field within the standard Model by utilizing CFD techniques. The thesis focuses on the temperature design of supply air, the influence on the platform brought by stopcock wind and local exhaust and the possibility of actualizing the VAV system.

在研究过程中运用CFD模拟的方法，选用标准湍流模型作为物理模型，在优质的网格生成的基础上，对所要研究的物理量进行离散化处理；并就空调送风温度的设定、活塞风、局部排风对站台热环境的影响、全天VAV环控方案实现的可能性等作了详细的理论研究与模拟分析。

Two commonly used methods of watershed segmentation were compared and analyzed. One is subarea method, and the other is grid method.

本文分析比较了流域空间离散化的两种途径：子流域法和网格法，并以此对流域径流过程模拟的影响进行了探讨。

In this paper, the maximum likelihood algorithm with process and measurement noise for nonlinear continuous-discrete system given by Jategaonkar and Plaetschke is improved in two aspects: 1 to avoid the disadvantages of sensitivities computation by common finite-difference method, in which the perturbation sizes should be selected optionally, an improved finite-difference method with best perturbations, is presented. 2 to improve the numerical stability of Jategaonkar's algorithm, maximum likelihood algorithm with fast triangular square-root decomposition filter is given.

摘要对Jategaonkar等人给出的同时计及过程及观测噪声的非线性连续-离散系统的极大似然算法从两个方面进行了改进：1给出了计算灵敏度的最佳摄动有限差分算法，避免了普通有限差分法计算灵敏度矩阵时需人为选择参数摄动量大小而带来的缺点；2给出了具有快速三角化平方根滤波的极大似然算法，提高了原算法的数值稳定性。

Then simulation tests of molding and UCS(unconfined compressive strength)were done with the DEM program, and the macroscopic character of different gradation and cohesion strength were compared.

然后利用离散元程序进行试件的成型和无侧限抗压强度模拟试验，对不同级配和粘结力下试件的宏观表现进行比较，并记录试件的破坏过程。

With finite differential method, the discretization equations are derived by chosing control volume integral method to solve the unsteady one-dimensional heat conduction question with variable physical properties, and the temperature distributinn in ladle lining in preheat is computed.

应用有限差分法，选用控制容积积分法推导出离散化方程组，对一维不稳定态变物性热传导问题进行求解，计算出钢包在预热过程中包衬的温度分布。

Nevertheless, the 3D-FEM based buffeting analysis will not only lead to the solution of high degree random differential equations, but also require to deal with wind-force spectrum matrix with very high degrees.

但按三维有限元方法进行抖振分析时，不但要面临高阶随机振动微分方程的求解，而且在将连续型的抖振力风荷载离散化的过程中，还要处理阶数很高的风功率谱。

Arterially perfused rabbit left ventricular preparations were used in the present study to simulate LQT2 by perfusing with d-sotalol. Transmembrane action potentials from epicardium and endocardium were recorded simultaneously, together with a trasmural ECG, in arterially perfused rabbit left ventricular preparations by use of 2 separate intracellular floating mocroelectrodes.

为探讨心室肌跨壁复极离散和心脏兴奋的恢复性质在长QT综合征室性心律失常发生过程中的作用，应用冠状小动脉灌流的兔左室肌楔形组织块标本，分模型组和对照组，采用浮置玻璃微电极法同步记录心室肌内、外膜心肌细胞动作电位和跨壁心电图。

The flow discharge at that point can be used as the estimated value of the bankfull discharge.

若以流量为参数，高含沙水流含沙量与流量构成一维离散动力系统；对于一般挟沙水流，含沙量随流量演化过程中的临界点，出现在流量与含沙量乘积为某一定值之时，该临界点处流量为平滩流量估算值。

During the numeric model processes, the finite element method is used to build the discrete model and analytical theory of the rotor-bearing system. The entire system is divided into several dividable substructures, each of which develops individual systematic mathematic model. Finally, the motion equation of whole structures is combined by the integrity of the dynamic variables and force balances on connections of each substructure.

在数值建模过程中，以有限元素法为基础，建立转子-轴承系统之离散模型与分析理论，将整个系统结构划分成若干个可分离部位的子结构系统，并发展子结构的个别系统数学模型，最后整体结构的运动方程式再以各子结构结合面上节点的动态参数一致性及力系平衡进行结合。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。