文氏管

This study presents the investigating of microchannels flow. It is divided into two parts, the flow characteristics of micro venturi and the performance of straight-walled and curved-walled micro nozzle/diffuser respectively. The experimental results are also compared with the simulation results whereby we can observe the flow field in micro venturi and discuss the bounder effect of micro nozzle/diffuser.

本文主要是针对微喷嘴的空气流场进行研究与探讨，研究分为两部分进行，分别是探讨微文氏管的流力特性及曲面微喷嘴边界对流力效能的影响，并将实验结果与CFD软体的分析结果相互比较，藉以观察微文氏管内之流场分布并探讨微喷嘴较佳之流力性能。

So a kind of two-grade dust catcher system with higher efficiency, convenience and mechatronic is studied. The designed dimension of the first- grade cyclone separator is optimized by using MATLAB optimization toolbox. New designed cyclone separator has lower resistance loss, higher efficiency, compact structure and less volume; The mathematical model of hydrometry is b...

在其一级旋风除尘器的尺寸设计中采用MATLAB的优化工具箱进行优化，经过试验证明，新设计的旋风除尘器为低阻高效除尘器，并且结构紧凑体积小；在二级文氏管除尘器中，根据其节流特性，结合流体力学原理，建立起流量检测的数学模型，据此引入与之配合的传感器和单片机系统，实现了流量的动态显示，为除尘设备机电仪一体化的研究奠定了基础。

In other instruments, the stream is accelerated through a Venturi or nozzle.

在其他仪器中，液流则是通过文氏管或喷嘴加速的。

Heat and mass transfer with spraying in Venturi tube is very complex in converter coal gas recovery system.

在转炉煤气回收系统中，文氏管内部有喷射行为的传热传质非常复杂。

And the Venturi tube's automotive control of Caterpillar Ltd.

本文主要介绍了国外海卓玛蒂克公司的DA自动变速系统和林德公司的AV自动变速系统，并简要介绍海卓玛蒂克的电子控制和卡特彼勒公司文氏管控制自动变速系统。

Then the flow in the curved pipe and reducing pipe was simulated through using CFD software, know that fluid passing curved pipe, reducing pipe can form secondary flow, vortex shedding, circumfluence, occur separation of boundary layer and periodic circulation flow, make the fluid pulsant, then cause the pipe vibrancy.

然后再应用通用CFD软件对具有弯曲和变径的热风炉管内流场进行模拟，得到当流体流过弯管、文氏管后形成了二次流、环流，并发生边界层分离和周期性旋涡脱落，它们会使后面的管流处于脉动状态，脉动状态的流体在管内流动时，会引起管道系统产生振动。

There's no venturi tube in the mouth of bag or blowing tube, that reduces working resistance and makes examining and repairing easy. Electromagnetic pulse valve is of these characters: be sensitive to control, high efficiency, long life span and so on.

滤袋上口不设文氏管，也没有喷吹管，降低了工作阻力，使检修、维护都相当简便，电磁脉冲阀具有控制灵敏、效率高、寿命长等特点。

Keywords sodium hypophosphite;venturi-duct;wet dust collector;cyclone separator;PH3 tail gas

次磷酸钠；文氏管；湿式除尘器；旋风分离器；磷化氢尾气

First, we adopt MEMS technology to fabricate micro venturis with different widths of 150 and 200 um respectively and utilize FLUENT software to analyze the flow fields. Air was set as the working fluid and the air mass flow rate of inlet is changed to obtain the pressure drop between inlet and outlet. When a flow passes through the throat, the backflow results in the symmetric separations occur and grow with the increase of mass flow rate.

在微文氏管的研究部分，首先利用微机电制程技术制造出两种不同尺寸的微文氏管，宽度分别为150及200微米，开口角度各为45°，总长则为10 mm，再以空气作为工作流体，利用不同质量流率来量测微文氏管进出口的压力差并配合FLUENT软体分析观察其流场分布的情况。

In this system,single Venturi tube , floral hoop in series and wire mesh dehydrator are used instead of the dedusting process of electric precipitator and Venturi tube in series.

该系统采用单根文氏管、串联花环、丝网脱水器湿法除尘，取代原串联文氏管电除尘净化工艺。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。