查询词典 transient

The nonlinear hyperbolic conservation laws of the transient flow of the media in gas pipeline are hard to he solved, so, the control conservation laws are constituted of mass, momentum arid energy conservation laws, TVD/Godunov hydrid algorithm is used to simulate the transient flow in gas pipeline, and the traditional splitting approach processing nonlinear convection in momentum equation is dismissed ,the convection tern; is directly processed, in the way, the stablization of the algorithm and emulating accuracy of the transient flow are greatly improved.

针对管道中介质瞬变流动的非线性偏微分方程组难以解析求解的问题，由质量、动量、能量三个偏微分方程构成的控制方程组，应用TVD/Godunov混合算法数值模拟天然气管道中气体的瞬变流动，摒弃了传统的差分方法时动量方程非线性时流项的线性化处理，而直接处理非线性对流项，从而大大提高了算法的稳定性和管道瞬变流动的仿真精度。

Incurrent research, aiming at the rupture problem engendered in the shooting process of acertain 5.56mm automatic rifle, the strain and stress distributions on the cartridge caseunder the action of axial pull have been analyzed. Based on the theories of elastic-plasticmechanics and contact mechanics, a mathematic and physical model of the cartridge-caseand chamber system has been set up; and based on the platform of the general softwarepackage APDL of ANSYS for finite element analysis, a parameterized model of thecartridge-case and chamber system has also been established. The method for nonlinearFEA has been adopted to analyze the stress distribution on the entire cartridge-case andchamber system, and the method of contact element has been employed to investigate thecontact stress between the cartridge case and chamber, and then the influences of frictioncoefficient and locking space on the static and dynamic stress and strain response of thecartridge case and chamber to the action of power gas have also been discussed. On thebasis of a lot of numerical tests, a kind of element Plane13, which is concentrated incoupled computation of heat and construction, has been used finally to simulate thetransient response of the cartridge-case and chamber system to the power gas. Throughloading the temporary thermal characteristics of explosive gas in the procedure of emulate, the corresponding transient thermal stress distributed on the entire system under thecombined load of transient thermal stress and transient pressure has been obtained. Owingto these comprehensive considerations, the numerical results obtained in this paperrepresent the actual situations comparatively exactly.

本文针对某5.56mm自动步枪在工作中出现断壳的问题，分析了弹壳在轴向拉力作用下的应力应变；基于弹塑性力学及接触理论，建立了弹壳弹膛系统的数学、物理学模型，在通用有限元ANSYS软件的参数化建模工具APDL平台上，建立了弹壳弹膛系统的参数化模型；采用非线性有限元法计算了弹壳弹膛系统的整体应力，引入接触单元法分析弹壳和弹膛的接触压力，探讨了在不同的摩擦系数和不同的闭锁间隙对弹壳弹膛静、动态响应的影响；本文进行了大量的尝试，最后确定采用热、结构耦合单元Plane13，在计算中加载了火药气体的温度历程，成功的获得了弹壳弹膛系统在瞬态的热载荷和瞬态的压力载荷同时作用下弹壳弹膛系统的热应力数值解，考虑因素全面，比较真实的反映了弹壳弹膛系统在火药气体压力和热载荷下作用的情况。

A computer-aided local transient flow property measuring system was developed using a high speed CCD camera coupled with optical fibers in order to study the Gas-liquid-solid three-phase jet loop reactors. SnO2 crystal films were orientally deposited on the alkoxysilane molecule-coated hydroxyl glass substrates so as to prepare surface-marked particles as the tracers. An image analysis system was established to identify different phases. Stroboscopic photography was utilized to extend the measure range. The developed measuring and analysis system was capable of determining accurately the local transient flow property in a G-L-S jet loop reactor. Based on the above system, local transient flow properties of gas, liquid, and solid phase were measured and studied the influences of fluid property, operation and configuration parameters on the reactor.

中文摘要：以气液固三相喷射环流反应器为研究对象，将高速CCD和光纤束耦合制成局部瞬态流动特性微机数据采集及图象处理系统，利用MPS硅烷分子在带有羟基的玻璃基底上的自组装引导SnO2晶态膜层在功能化表面上进行沉积，以获得表面标记的示踪粒子，解决图象处理技术与相的识别的问题，利用频闪技术拓展了测量上限，得到可以准确测定气液固三相喷射环流反应器中局部瞬态流动特性的测试系统；采用上述测试技术进行喷射环流反应器中局部气相、液相与固相瞬态流动特性的实验研究，并考察物性参数、操作参数与结构参数的影响规律。

Other conclusion include: the trip of transient protection must be locked when the power circuit breaker of transimission line operated,because the trip is incorrect at this time;the features of transient current and its energy is different between the fault and thunder over- voltage in transimission line,and them can be identified;the ratio of high frequency component of current in serise capaciters compensation line , SVC and HVDC system is far little than fault transient current, so all of them do not affect the working of trasient current protection.

研究了在串联补偿电容的输电线路上发生故障时，串联补偿电容的MOV非线性保护电路对暂态保护的影响。串补电容MOV保护电路的非线性电流高频分量含量很小。静止补偿器、高压直流输电系统换流器的非线性特性产生的谐波分量含量极少。仿真计算表明，在与暂态保护判据中高频分量对应的频率范围内，其电流对应的功率谱估计值大大低于线路故障时故障电流的功率谱估计值，因此它们都不会对暂态电流保护的正常工作产生影响。

In this paper, using transient energy function as the assessment of system stability and applying the derivative of TEF to determine the control strategy of Fault Current Limiter with controllable series compensation in transient stability process, the transient stability characteristics can be effectively improved and subsequent oscillation can be quickly damped.

1引言具有可控串联补偿功能的故障限流器(FCL with controlled series compensation)作为灵活交流输电的主要装置之一，装设在并行线路具有许多优点。如图1所示，正常工作时，它能连续、快速、大范围地调节线路阻抗，从而灵活调节线路电流、增强系统阻尼、改善系统动态性能、抑制次同步振荡。

Ground parts: an overhead-type indicator by sampling ground capacitance transient current in the first half-wave and ground transient voltage in the first half-wave, to compare their phase, when the sampling ground capacitance transient current mutation and more than a certain value, and the instantaneous voltage and grounding The first-phase half-wave, while wire-to-ground voltage is reduced, then the judge circuit grounding occurred.

接地部分：架空型指示器通过采样接地瞬间的电容电流首半波与接地瞬间的电压首半波，比较其相位，当采样接地瞬间的电容电流突变且大于一定数值，并且与接地瞬间的电压首半波同相，同时导线对地电压降低，则判断线路发生接地。

On Flight 5, we performed the first afterburner engine transient as well as performing other engine transient testing.

在第5次试飞时，我们实验了首次加力状态下的发动机瞬态并同时实验了其它的一些发动机瞬态测试。

This paper analyzed thoroughly the transient electromagnetic field analytic expression in homogeneous half space, discovered that the transient response curve has a characteristic of translational expansion and contraction with the underground conductivity, transmit loop length and observation time. According to that, we proposed a new direct method to calculate full time domain apparent resistivity.

深入分析了均匀半空间中瞬变电磁场的解析表达式，发现瞬变响应曲线随地下电导率、发射回线边长与观测时间具有平移伸缩特性，并据此提出了一种新的直接计算全区视电阻率的方法。

The proposed method has the merit that the numerical characteristics of stochastic temperature field response can be obtained by analyzing the random temperature field just in one time.3. Perturbed numerical algorithm of nonprobabilistic convex set theoretical models on the temperature fieldThe uncertain parameters of physical parameters and initial boundary conditions of heat conduction are described by the convex model. The perturbation formulas of the upper and lower bounds of temperature field response with unknown-but-bounded parameters are given via the combination of matrix perturbation theory and the convex set theory model.4. Numerical analysis for transient temperature field with interval parametersConsidering the uncertainties of the transient heat transfer, the physical parameters and initial boundary conditions are regarded as interval variables.

该方法具有只进行一次随机温度场分析便可以获得其响应的数字特征的优点。3、温度场的非概率凸集合理论模型的摄动数值解法将结构导热的物理参数、温度场的初始和边界条件等不确定性参数以凸模型加以描述，基于矩阵摄动理论和处理不确定问题的凸集合理论模型的结合，导出有界不确定参数瞬态温度场响应所在集合的上、下界摄动计算公式。4、具有区间参数的瞬态温度场数值分析考虑结构瞬态热传导问题的不确定性，将结构各物理参数和温度的初、边值条件均视为区间变量。

The transient design problems of high-frequency transformer and its buffer circuit of main circuit are discussed in detail and the influence of variation of the elements parameters on the main circuit transient behavior is explored qualitatively and quantitatively.

围绕逆变电源主电路动态过程的设计问题，重点讨论了功率脉冲变压器及其缓冲电路的设计要点，定性和定量地探讨了器件参数变化对主电路动态过程的影响，在仿真的基础上，实现计算机辅助优化设计。

The system can be widely used in belt weighing and batching process control,etc.

介绍了基于智能模糊控制的嵌入式配料系统的设计方法，对模糊PID控制过程和系统调零作了重点的讨论，同时给出了PID控制的程序流程图和系统定长调零子程序。

"I dunno," she answered,"but if you show me aroun', I'll recognize it from the lighthouse just outside the porthole."

"我不知道，"她回答说，"如果你能带我转转，我能认出来的，因为灯塔就在舷窗外。"