查询词典 transient current

The transient natural convection and natural convective heat and mass transfer under constant-flux condition were also studied respectively. In experimental research, the electrochemical method was used to analogize natural convection in a porous enclosure.

在实验研究中，采用电化学方法，在多孔介质封闭腔体的两竖壁间建立浓度梯度和温度梯度，实验测量了腔体内的温度分布和电极间的极限电流，以此确定了总体的传热系数和传质系数。

An iterative temperature field model of cylinder, in which the non-linear steam temperature distributed along axial direction, was got based on two-dimensional transient heat conduction differential equation. Analytical simulation demonstrates not only a rapid solution convergence but a minor error.

在二维圆筒壁非稳态导热的基础上，得到了圆筒壁内蒸汽沿轴向线性分布，随时间非线性变化的温度场迭代计算公式，并与有限元计算结果作了对比，结果表明所得模型计算精度高、计算速度快。

The main work and the originality points of this dissertation could be concluded as the following parts:(1) To analyze systematically the mathematical model of LES of air flow in great space, under the case of isothermal and non-isothermal, as well as the combined action of buoyancy and strain. Some basic problems are studied about the LES application into airflow simulation of great space, such as boundary conditions, spatial difference scheme and time advancing scheme, time step etc., which creates the basis for the LES application to indoor airflow simulation.(2) Both the instantaneous and time averaged flow field of great space with multiple jets under isothermal and non-isothermal cases are explored with large eddy simulation method, and also discussed the dynamic characteristics and the law of fluidflow in the great space.(3) Based on the results of LES of the great space and the Fanger thermal comfort indexes, it is brought forward the concept of the series of dynamic thermal comfort evaluating indexes, which could be divided into thermal comfort index with time averaged properties PD, PPD, PMV, thermal comfort index with instantaneous properties IPD, IPPD, IPMV, and time averaged thermal comfort indexes TAPD, TAPPD, TAPMV, and transient situations time averaged thermal comfort indexes TTAPD, TTAPPD, TTAPMV. The differences among them and the calculation methods are discussed, and the four kinds of indexes are calculated with the thermal comfort index PD as an example.(4) Based on the LES results it is discussed the hot air stratification phenomena in air-conditioned buildings in the case with air supply and return registers on the ceiling and the case on the sidewall. The fundamentals of the hot air stratification are studied and the relations of estimating hot air stratification are brought forward.(5) With the advanced apparatus such as hot wire film anemometer IFA300 and laser particle field anemoscope, corresponding model test and site measurements have been done, which are compared with the simulation results and LES is proved a very promising method in air flow simulation indoor.

本文主要工作既创新点体现在以下几个方面：(1)系统分析了等温、非等温和考虑剪切力与浮升力综合作用的高大空间大涡模拟数学模型，并研究了高大空间大涡模拟在室内气流仿真应用中的一些基本问题，如边界条件、空间离散格式和时间推进格式、时间步长选择等问题，为大涡模拟在室内气流计算中的广泛应用打下了基础；(2)首次用大涡模拟方法研究了高雷诺数下高大空间多射流在等温、非等温情况下的瞬时流场和时均流场分布，并探讨了多射流流场的动态特性和流动规律；(3)基于大涡模拟的动态仿真结果和Fanger的热舒适指标，首次系统地提出了动态热舒适评价指标体系的概念：即基于时间平均参数的热舒适指标PD、PPD、PMV；基于瞬时参数的瞬时热指标IPD、IPPD、IPMV；基于时间平均热舒适指标TAPD、TAPPD、TAPMV；以及沿行动迹线的时间平均热舒适指标TTAPD、TTAPPD、TTAPMV，并分析了四类热舒适指标的差异性和计算方法，还以PD值为例对四类指标分别进行了计算；(4)基于数十种工况下空调房间大涡模拟的结果，研究了空调建筑上送上回和侧送侧回两种情况下热分层现象，并探讨了热分层的基本规律，首次提出了避免热分层现象的判断公式；(5)在暖通空调领域，首次使用IFA300热线风速仪、激光粒子速度场仪等先进设备，完成了与大涡模拟相对应的模型试验，并把实测结果与仿真结果进行了对比，说明LES在室内气流仿真方面是一种很有前景的方法。

The model is implemented with the circuit simulation tool PSPICE, and can be used to analyse oscillating properties, including the detection mode transient response, stable response and frequency response to angular rate.

利用这个电路模型，可以分析陀螺的振动特性，包括检测振动的瞬态响应和稳态响应，检测振动对输入角速度的频率响应特性，从而可以获得陀螺工作的优化条件；并为传感器与接口电路的整体模拟打下基础。

In order to deduce the engine control law during the helicopter autorotation, simulation was made to demonstrate the transient process of the engine when entering the helicopter autorotation condition using normal control law. Based on the existing control law, an improved law was brought forward by magnifying the differential gain of collective pitch "anticipator" and broadening the deceleration limitation.

为确定直升机自转下滑训练过程发动机的控制规律，分析了采用正常控制规律进入自转状态时涡轴发动机的变化过程，提出了在现有控制规律基础上增强动力涡轮转速控制模块中总矩"提前器"作用和适当放宽速率限制值的控制对策。

The relationship between transient response and shape design variables is highly non-linear, and the behavior of feasible domains is often not good, which may cause convergence difficulties. In order to improve convergence speed of iteration process, some algorithms the feasible domains adjusting, the adaptive move limit, the approximate line search and the approximate reanalysis, are adopted.

采用基于Newmark积分的直接求导法计算瞬态响应灵敏度，在序列二次规划算法中采用了可行域调整、近似—维搜索、自适应运动极限等改进技术，提高求解效率和收敛稳定性，以解决结构动态响应与设计变量的关系复杂、高度非线性，优化可行区域的性态不良等问题。

The theory of function approximation is used to establish the transient model of thrust vectoring with the data calculated.

利用该程序计算了某矢量喷管在不同的压比、面积比和几何偏转角下的200多种三维有粘流场，获得了矢量喷管的性能数据。

There was no open warfare between the two women; there was only an armed neutrality, broken every now and then by brief feminine skirmishes and transient wordy tempests.

这两个女人之间倒没有公开的战争；仅仅存在着一种武装的中立状态，时而有些短促的婆婆妈妈的小冲突或转瞬即逝的咬文嚼字之争，打破了这种中立。

However,studies on marine ascidian skeletons have revealed that ACC as a transient precursor to crystalline CaCO3 can stably exist for long time in organisms,and the stable ACC is usually membrane-embedded.

但由海鞘类动物的研究表明，ACC可作为碳酸钙晶体矿物的前驱体在生物体内稳定存在，并且这些生物成因的ACC常常是由膜包裹着的。

However, studies on marine ascidian skeletons have revealed that ACC as a transient precursor to crystalline CaCO3 can stably exist for long time in organisms, and the stable ACC is usually membraneembedded.

但由海鞘类动物的研究表明，ACC可作为碳酸钙晶体矿物的前驱体在生物体内稳定存在，并且这些生物成因的ACC常常是由膜包裹着的。

Continuously improve the production mechanism, to provide customers with better quality products and services.

不断的完善生产机制，给客户提供更优质的产品及服务。

B:Yes, he was the very prize-winner in the court tennis ten years ago?

是的，他是十年前的世界网球冠军。