数值方程

This method uses the generator model of constant transient voltage and the saliency of generator is included.

本文提出了一种基于特殊二阶微分方程数值积分的电力系统动态安全评价方法。

In order to practically predict the effect of the tree belt windbreak in mine-area environment protection, the flow through porous tree belts was numerically made. The airflow-tree canopy action was considered into the momentum equation as the resistance term, and then the resistance between obstruction and airflow was expressed numerically.

为了更好地发挥防护林带在矿区生态环境保护中的效用，采用数值模拟的方法预测防护林带的绕林流场，其中将气流－树木相互作用视为阻力项添加到动量控制方程中，由障碍物表面对空气流动的阻力来描述林带的遮蔽效应。

Then discuss whether the trivial solution will bring the Hopf bifurcation problems or not, at last model the equation using Matlab.

最后，本文利用Matlab对这一类时滞微分方程做出了相应的数值模拟，对所求的数据准确性进行了验证。

This paper presents a new method for water wave animation based on the two- dimensional shallow water equations.

本文基于二维浅水波方程模型，给出了一种实现水波动画的数值模拟方法。

The two- and three- dimensional cases are discussed in this paper.

于是对分数阶微分方程进行数值求解变得尤其重要。

According to the seepage equation of the groundwater and using the finite element method, this thesis establishes the mathematics model for two and three dimensional seepage.

采用有限元理论，以地下水渗流方程为基础，针对基坑降水建立了地下水的二维和三维渗流数学模型，完善了深基坑降水渗流计算方法。对某一假定的深基坑降水工程分别进行二维和三维渗流数值模拟。

Depicting three directions plot of displacement of tympanic membrane according to the analytic solution and comparing t...

并由此得到耳膜位移的三维图像，再与有限元数值模拟、解剖学得到图像相对比，证明此方程的正确性。

A subject was selected strictly from 30 healthy young people through nasal endoscopic examination, acoustic rhinometry measurement and CT scanning. Based on the CT image data of the subject, digital model of normal nasal cavity was reconstructed through Fluent 6.1.22 software. At the same time, according to the surgical requirements of FESS (remove the uncinate process and open the ethmoid sinus, maxillary sinus, and sphenoid sinus), post-FESS digital nasal cavity model was simulated. The viscous motion of nasal airflow before and after FESS was calculated by Navier-Stokes equations to compare the differences of airflow velocity, distribution, and pressure.

从30例健康青年人中，通过鼻内镜、鼻声反射测定仪及CT检查，严格筛选出一例研究对象，根据该入选对象的鼻腔CT影像资料，利用Fluent 6.1.22软件重建出正常鼻腔的数字模型，同时根据功能性鼻窦内镜手术的要求（切除钩突，开放筛窦、上颌窦和蝶窦）模拟出鼻内镜术后的鼻腔数字模型，再用Navier-Stokes方程对手术前后鼻腔气流的粘性运动进行数值计算，比较内镜手术前后鼻腔的气流速度、分布和压力的差异。

In the field of nature and engineering, inverse problems of undetermined parameter are often met.

最近20年来有关偏微分方程反问题的研究，从理论到方法上虽然取得了重大进展，提出了不少有效的数值方法。

Numerical simulations were done for a bistable latch valve of the system by FLUENT, and three groups of datum for different fluids were obtained with the same effective exit sectional area. Besides, a static mathematic model for the electromagnetic valve was established based on the obtained datum. Secondly, the motion of the valve spool was realized by UDF file in FLUENT. Three kinds of motions, uniform, acceleration and motion driven by the coupling effect of the liquid resistance and the electromagnetic force, were calculated and compared. The dynamic characteristic of the electromagnetic valve was obtained by analyzing the relationship of the mass flow rate of the inside flow field of the electromagnetic valve, the change of the drop pressure of the passageway of the valve, and motion time.

并针对系统中的某双稳态电磁阀，使用商用CFD软件FLUENT对其进行内部流场的数值模拟，通过使用不同流体介质，不改变阀门有效出口截面积的情况下，分析得到的三组数据，建立了该电磁阀的静态数学模型；通过编写UDF文件，实现对阀芯运动方程的控制，在阀门做由闭合到开启、开启到闭合运动时，控制阀芯分别做匀速运动、匀加速运动以及阀芯受到液体阻力与电磁力作用力的耦合力的运动，分析了三种工况下电磁阀内部流场质量流率和阀门出口入口压降的变化以及运动时间，从而得到该电磁阀的动态特性。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。