查询词典 simulation

The analysis shows that with given grid size higher accurate difference scheme can give higher resolutions with wider range of scales, or with given accuracy large grid size can be used for the higher accurate difference scheme. The second part is the numerical simulation of two-dimensional axisymmetric jet. The simulation results show the structure in the near field and the initial transition. In the near field, Kelvin-Helmholtz instability leads to the formation of vortex ring, and nonlinear growth leads to the merging of vortex ring. This is the main instability form. Under the assumption of axisymmetry and two-dimensional computing conditions, the results are applicable only in the near field.

第二部分采用高精度的差分格式对二维轴对称射流进行了数值模拟，模拟结果显示了射流流场结构和涡结构的发展过程，在射流流场近区，K-H失稳导致涡环的产生以及非线性效应的增长导致涡环的对并是射流失稳的主要形式；分析指出在轴对称假设下的射流数值模拟只适用于射流近区的分析。

It is available to carry out numerical simulation and fluid dynamic analysis further. Based on Frozen-Rotor Approach and Rotor-Stator Approach, the numerical simulation was carried out in the centrifugal pump and the numerical results showed that the flow in the impeller and volute of centrifugal pump is periodically unsteady. Due to the interaction between impeller and volute the flow is characterized by pressure fluctuations and it is the strongest at impeller outlet and at the vicinity of the tongue. The unsteady pressure fluctuations are also one of the most important reasons to induce vibration and noise. Secondly, the flow field of the volute is characteristic of the vortex flow, and the vortex flow presents very complicated developing process which is creating, increasing and dissipating every now and then. All these lead to very large flow loss in the volute.

采用Frozen-Rotor冻结转子模式和Rotor-Stator滑移界面模式系统开展了不同工况下离心泵内叶轮与蜗壳耦合的定常和非定常流动研究，结果表明由于叶轮与蜗壳的干扰蜗壳进口周向流动的不均匀性是非常强烈的，特别是叶轮与蜗舌间的相互干扰最为强烈，一直影响到叶轮进口和蜗壳扩散管出口的流场；在蜗壳内整个流动是以旋涡形式向出口推进的，并随着包角的变化旋涡表现出十分复杂的产生、发展和耗散的演化过程，导致蜗壳内较大的流动损失。

The advantage of CFD numerical simulation especially displays in the development of the new products, it not only can replace theroutine experiment and offer various kinds of flow characteristic parameters by a large margin , It not only can replace conventional experimental substantially provide various flow parameters, and reveals through three-dimensional flow field pattern to optimize design based on detailed. CFD numerical simulation in this text applications will greatly enhance the cage control valve design and the technical level and product quality, reducing cage control valve design and processing cycle, significant cost savings, And optimizes through the flow channel, to reduce fluid flow through the valve of energy loss, improving efficiency in the use of energy have the extremely vital significance.

CFD数值模拟的优势尤其表现在新产品的研制开发中，它不但能大幅度取代常规实验提供各种流动特性参数，而且能通过揭示流场三维分布形态为优化设计提供详细依据；文中所采用CFD方法必将大大提高套筒型调节阀设计的技术含量与产品质量，可缩短调节阀的设计和加工周期，节省大量成本，并且通过流道优化，对降低流体流过调节阀的能量损失，提高能源利用率等具有十分重要的意义。

This paper presented the main functions and characteristics of Multisim8.0, and the main qualities of high frequency tunable amplifier such as voltage gain, transmission bands and selectivity were studied using simulation analysis and testing technologies of Multisim 8.0. The results are visual and precise, and prove the theory very well. This software has powerful simulation and analysis function, by which the analysis and design of high frequency circuit are not only more precise and credible, but also more closed to the real circuit running status.

本文介绍了Multisim8.0仿真软件的主要功能及特点，并结合该软件对高频单调谐放大电路的电压增益、通频带、选择性等主要质量指标进行了测试与仿真分析，结果直观、精确，很好地验证了理论，表明该软件有强大的仿真和分析功能，在实现高频电路分析和设计方面不仅高效、可靠，而且具有逼近真实电路的效果。

Simulation results show that the method solves dynamical product of HRTF data based on moving sound sources and the smooth transition of the fore-and-aft sound sequence signals. The method is more reliable and accurate than other methods, and realizes indoor acoustic simulation based on dynamic mechanism.

仿真结果表明，该方法较好地解决了运动声源HRTF数据的动态产生和前后声信号段平滑过渡问题，具有更好的真实性和精确度，实现了基于动态机制的室内声学仿真方法。

Based on the water environment spatial data mining and visualization method, the paper presents these main characteristics and innovations:①Measurement of contamination fluxes:A scene-based research strategy is proposed:measurement /water quality analysis→flow field simulation→contamination transformation rule→fluxes scene simulation→temporal-spatial rule analysis.②Serial numerical models of water environment in the Qiantang River:The controlled equations of the flow field model of the main river,united controlled equations of the main contamination fluxes and water quality prediction model at emergent time are set up.③GIS-based water quality and contamination fluxes decision-making assistance system:A water environment database has been set up;based on MapX and C#.net platform,a system has been developed to facilitate visual inquiry,decision-making and graphics export.

本文基于水环境空间数据挖掘与可视化的研究方法与体系，研究中的主要特色与创新点为：①河流污染物通量测算的技术与方法：提出了基于工况测量/水质分析→流场模拟→污染规律解析→通量情景模拟→时空规律分析的研究方案；②钱塘江水环境模拟系列数学模型：建立了钱塘江干流研究区域流场数学模型的控制方程、主要污染物通量模型的联合控制方程、突发污染事故水质预报模型的基本方程；③基于GIS的水质预报与污染物通量决策支持系统的研发：建立水环境时空数据库，基于MapX和C#。net平台进行系统的构建与开发，为研究的系列成果提供可视化的查询、决策与图形输出。

This method substitutes touch screen , LCD, virtual front-panel module, simulation computers and other simulation implements for Line Replaceable Unit of DCSS. And the paper sets up the distributed DCSS by LAN.

该方法采用触摸屏、液晶显示器、虚拟座舱面板组件、仿真计算机等仿真设备替代显控分系统的外场可更换单元，通过局域网将多台仿真仿真终端连接起来替代显控处理计算机。

Study on numerical simulation for top beam of MPF press According to the result of numerical simulation for top beam, the unreasonable parts are improved for its configuration.

多点成形压力机上横梁的数值分析根据压力机上横梁的数值模拟结果，对不合理的部位进行了整体结构改进。

Based on the geometry constraint and dimensiondriving technique, a 3-UPU parallel simulation mechanism is created. Then a 3D free surface and a guiding plane of tool path are constituted, with the 3-UPU parallel machine tool combined, a novel 3-UPU simulation parallel machine tool for machining a 3D free surface is created.

通过几何约束和尺寸驱动技术，先建立3-UPU并联模拟机构，再构造任意3D自由曲面和刀具轨迹的引导平面，与3-UPU模拟并联机构合成，得到用于加工任意3D自由曲面的模拟并联机床。

Based on the geometry constraint and dimension-driving technique,a 3-UPU parallel simulation mechanism is created.Then a 3D free surface and a guiding plane of tool path are constituted,with the 3-UPU parallel machine tool combined,a novel 3-UPU simulation parallel machine tool for machining a 3D free surface is created.

通过几何约束和尺寸驱动技术，先建立3-UPU并联模拟机构，再构造任意3D自由曲面和刀具轨迹的引导平面，与3-UPU模拟并联机构合成，得到用于加工任意3D自由曲面的模拟并联机床。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失