文档介绍：Chapter 11
Fluid Mechanics
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第十一章气体射流
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Chapter 11 Gas diffusion
§11–1 Introduction
§11–2 Character of submerging turbulent diffusion in infinite space
§11–3 ic analysis of diffusion in circular section
§11–4 plane diffusion
§11–5 Temperature or thickness difference of diffusion
§11–6 Introduction of other diffusion in project and equipment
Exercise of Chapter 11
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第十一章气体射流
§11–1 引言
§11–2 无限空间淹没紊流射流的特征
§11–3 圆断面射流的运动分析
§11–4 平面射流
§11–5 温差或浓差射流
§11–6 工程设备中常见的其他射流简介
第十一章习题
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Flow by gas diffusing from orifice, pipe mouth or slot called gas submerged diffusion orifice velocity is high,flow is in turbulent state, called turbulent diffusion. Most diffusion applied in engineering is turbulent diffusion of gas.
Diffusion describe flow velocity, temperature and thickness ing out.
Diffuse to infinite space, flow is not restricted by solid wall called free ,called restricted diffusion.
Chapter 11 Diffusion of gas
§11-1 Introduction
Gas diffusion
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气体射流
气体自孔口、管嘴或条缝向外喷射所形成的流动,称为气体淹没射流。当出口速度较大,流动呈紊流状态,叫做紊流射流。工程上所应用的射流,多为气体紊流射流。
射流讨论的是出流后的流速场、温度场和浓度场。
射流到无限大空间中,流动不受固体边壁的限制,为无限空间射流,又称自由射流。反之,为有限空间射流,又称受限射流。
第十一章气体射流
§11-1 引言
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§11-2 Characteristic of turbulent diffusion in infinite space
Take circular section diffusion as example talk about diffusion motion.
Airflow diffused from circular section muzzle with radii R .Velocity of outlet section is considered uniform distributing , all are u0 and is turbulent flow. Take axis of diffusion Mx as axis x
Owing to diffusion is turbulent flow type, transverse pulse of diffusion make exchange between mass and momentum among diffusion and medium moving, mass flux , transverse section area along x increasing , come into cone form flow diffused to around, as in —1 CAMDF。
Gas diffusion
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气体射流
§11-2 无限空间淹没紊流射流的特征
现以无限空间中圆断面紊流射流为例,讨论射流运动。
气流自半径为 R 的圆断面喷嘴喷出。出口断面上的速度认为均匀分布,皆为 u0 值,且流动为紊流。取射流轴线Mx为x 轴。
由于射流为紊流型,紊流的横向脉动造成射流与周围介质之间不断发生质量、动量交换,带动周围介质流动,使射流的质量流量、