流控制

The method of characteristics was introduced to calculate the flow field after the primary nozzle exit, whilst Korst's recompression criterion was adopted to determine the corresponding cell pressure, and one-dimensional control volume method was employed to analyze the downstream flow field.

该方法采用特征线方法分析一次流喷嘴出口流场，结合Korst再压缩判据确定引射器盲腔压力，采用一维控制体方法计算第二喉道引射器的下游流场。

Subsequently, the optimized technology was successfully scaled up to 〓 pilot bioreactor scale by using the parameter simulation method. The scale-down strategy was applied to the 100〓 fermentation tank to ascertain that the determining factor which affects metabolic flux distribution reasonably had changed to the dissolved oxygen control. After resolution of the DO limitation, the optimized technology inhibited the shift on 100〓 production scale correspondingly, notable commercial returns was gained as a result.

随后基于过程参数拟合的方法成功地将抑制代谢流迁移的新工艺放大到12〓规模，并通过规模缩小证实了100 〓生产规模的发酵过程中限制代谢流合理分配的限制性因素已经发生了变化，此时DO的控制成为优化的前提，通过改善供氧条件之后优化的工艺在生产规模也成功的克服了代谢流的迁移，取得了显著的经济效益。

In addition to measurements of conventional dynamic parameters o n a model surface,an optical observation method was employed,which directly reco rded self-luminosity of high temperature gas induced by a two-dimensional mode l in high enthalpy flow and combustion radiation.Hypersonic flow fields passing over a sharp strut including fuel injection were displayed and recorded with a high-speed CCD camera.A phenomenon of supersonic diffusive combustion under fre e boundary condition was observed.

实验除测量常规流场参数和模型表面的动态参数外，主要使用二维实验模型，利用高温气体的自发光和燃烧伴随的发光现象，采用高速摄影技术来观测燃烧现象，记录到高焓流场中叠加燃料喷射和燃烧的流场，观察到自由边界条件下扩散控制的超声速燃烧现象。

A fuzzy logic reasoning method is used to forecast traffic diversion volume and a fuzzy control algorithm is also applied to design the intersection signal setting of the route.The simul...

研究表明：交通流诱导负效应的产生主要是由于信息条件下的道路出行者路线选择行为的不确定性引起的，而且交通流诱导与控制同时进行是消除交通流诱导负效应产生的关键。

The paper improves the velocity's control rules of a first-order microcosmic stochastic traffic cellular automaton model and incorporates it's stochasticity as a deceleration parameter in the construction of the fundamental diagram used by a macroscopic first-order continuum traffic model.

本文对微观一维随机元胞自动机交通流模型的速度控制规则进行了改进，并将其随机特性转化为减速参数合并到宏观一阶连续介质理论交通流模型中，重新构建了反映流量——密度的交通流基本图。

In this paper, a total flow differential model of sediment density current was developped on the basis of analysizing its characteristics and simplifying its moving properties.

本文分析了异重流体的特点，对异重流的运动作了一些假设和简化，推导出了以总流为控制体的异重流微分模型。

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。

In this paper,a 3-D numerical simulation model is proposed to simulate and analyze the 3-D flow characteristics of natural spawning sites of Acipenser Sinensis by using N-S and k-ε formulas,the volume of fluid method is also used to simulate the two phase flow,and the finite volume method is used to disperse the calculated area.

将水动力学N-S方程、k-ε紊流数值模型与计算水气两相流的方法VOF相结合，采用控制体积法离散计算区域，建立了葛洲坝下游中华鲟产卵场的三维流场模拟模型。

The most heavy flow ability of barrage swirl is controlled by fastenning device and barrage size, the most heavy discharge is more when barrage aperture is bigger, the influence of barrage position on discharge is not obvious; The pressure of the end of the shaft and fastenning device increases which aroused by barrage, and there is a restraining action to flow waving of the shaft; The barrage aperture is smaller, the increase of pressure is heavier, the influence of position to the increase of pressure is not obvious; The positive pressure of the level section in the hole between fastenning device and barrage increases obviously, the change of press along length reduces, mural press in the hydrosphere separating area of outlet of fastenning device becomes positive pressure, which is propitious to the increase of flow cavitate number in the low pressure area of the outlet of fastenning device; The influence of change of swirl cavum diameter caused by barrage to ventilating state is obvious.

阻塞旋流最大泄流能力由起旋器及阻塞体型共同控制，降低了泄洪洞的泄流量，孔径大的阻塞最大下泄流量较大，阻塞位置对泄流量的影响不明显；阻塞引起竖井及起旋器端头压力增大，对竖井部分的水流波动具有抑制作用；阻塞孔径越小，压力增加越大，位置对压力增大影响不明显；起旋器与阻塞之间水平洞段的止压力明显增加，沿程压力变化减小，起旋器出口的水气分离区壁面压力变为正压力，有利于起旋器出口低压区水流空化数的提高；阻塞引起的旋流空腔直径变化对通气状态产生明显影响。

In this paper, magnetorheological fluids and it's rheological behavior were introduced. And the principle of the disc-shaped magnetorheological fan clutch was investigated theoretically. The Bingham model was used to characterize the constitutive behavior of MR fluids subject to an external magnetic field. Based on Bingham model the expressions of the torque and the output rotational speed within the clutch is derived to provide the theoretical foundation in the discal design of the clutch. Then the calculations of the radius of the disc, the thickness and volume of MR fluids within the MRF clutch are yielded. Finally, the sketch of the clutch was designed.

文中对磁流变液的材料及流变特性进行了介绍，分析了圆盘式磁流变液汽车风扇离合器的工作原理，基于Bingham模型建立离合器的力矩模型，结果表明离合器传递的力矩随外加磁场的变化迅速变化，力矩的大小可以通过调节磁场强度的大小来控制，进一步推导了离合工作半径，工作间隙厚度等设计计算公式，最后完成了离合器的原型设计。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。