nozzle1.ppt

8/10/2019 Nozzle1.ppt

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NOZZLENOZZLE



AAnozzlenozzle is a device designed tois a device designed tocontrol the direction orcontrol the direction or

characteristics of a fluid flow as itcharacteristics of a fluid flow as itexits an enclosed chamber or pipe.exits an enclosed chamber or pipe.



A nozzle is often a pipe or tube ofA nozzle is often a pipe or tube ofvarying cross sectional area, and it canvarying cross sectional area, and it can be used to direct or modify the flow of be used to direct or modify the flow of

a fluid (liquid or gas).a fluid (liquid or gas).

Nozzles are frequently used to controlNozzles are frequently used to controlthe rate of flow, speed, direction, mass,the rate of flow, speed, direction, mass,shape, and/or the pressure of theshape, and/or the pressure of the

stream that emerges from them.stream that emerges from them.



The flow nozzle is a type ofThe flow nozzle is a type ofdifferential pressure drop devicedifferential pressure drop device

In a differential pressure drop deviceIn a differential pressure drop devicethe flow is calculated by measuringthe flow is calculated by measuring

the pressure drop over anthe pressure drop over anobstructions inserted in the flow.obstructions inserted in the flow.



TYPES of NOZZLETYPES of NOZZLE



AAgas jetgas jet,,fluid jetfluid jet, or, orhydro jethydro jet isisa nozzle intended to eject gas ora nozzle intended to eject gas orfluid in a coherent stream into afluid in a coherent stream into a

surrounding medium.surrounding medium.

JET JET



Other types of fluid jets are foundOther types of fluid jets are foundin Jacuzzis or spas.in Jacuzzis or spas.

JET JET



Gas Stove



Jacuzzis



Another specialized jet isAnother specialized jet isthethelaminar jetlaminar jet. This is a water jet. This is a water jetthat contains devices to smooth outthat contains devices to smooth outthe pressure and flow, andthe pressure and flow, and

gives laminar flow, as its namegives laminar flow, as its namesuggests.suggests.

JET JET



Nozzles used for feeding hotNozzles used for feeding hot

blast into a blast blast into a blast

furnace or forge are calledfurnace or forge are calledtuyerestuyeres..



tuyerestuyeres



The goal is to increase the kineticThe goal is to increase the kineticenergy of the flowing medium atenergy of the flowing medium at

the expense ofthe expense of

its pressure and internal energy.its pressure and internal energy.

High Velocity NozzleHigh Velocity Nozzle



Convergent nozzlesConvergent nozzles accelerateacceleratesubsonic fluids.subsonic fluids.



Divergent nozzlesDivergent nozzles slow fluids if theslow fluids if theflow is subsonic, but they accelerateflow is subsonic, but they accelerate

sonic or supersonic fluids.sonic or supersonic fluids.



Convergent-divergent nozzlesConvergent-divergent nozzles cancantherefore accelerate fluids that havetherefore accelerate fluids that havechoked in the convergent section tochoked in the convergent section to

supersonic speeds.supersonic speeds.



Also known asAlso known asconvergent-divergentconvergent-divergentnozzlenozzle,,CD nozzleCD nozzle ororcon-di nozzle,con-di nozzle, is a tube that is pinched in theis a tube that is pinched in themiddle, making a carefully balanced,middle, making a carefully balanced,

asymmetric hourglass-shape.asymmetric hourglass-shape.

de Laval nozzlede Laval nozzle



A jet exhaust produces a net thrust fromA jet exhaust produces a net thrust from

the energy obtained from combustingthe energy obtained from combustingfuel which is added to the inducted air.fuel which is added to the inducted air.

This hot air passes through a high speedThis hot air passes through a high speednozzle, anozzle, a propelling nozzle propelling nozzle, which, which

enormously increases its kinetic energy.enormously increases its kinetic energy.

PROPELLING NOZZLEPROPELLING NOZZLE



Propelling NozzlePropelling Nozzle



Many nozzles produce a very fineMany nozzles produce a very finespray of liquids.spray of liquids.

SPRAYSPRAY



Atomizer nozzlesAtomizer nozzles are used forare used forspray painting, perfumes, sprayspray painting, perfumes, sprayon deodorants, antiperspirants andon deodorants, antiperspirants and

many other uses.many other uses.



SpraySpray (Atomizer Nozzles)(Atomizer Nozzles)



Air-Aspirating NozzleAir-Aspirating Nozzle uses anuses anopening in the cone shaped nozzleopening in the cone shaped nozzle

to inject air into a stream of waterto inject air into a stream of water

based foam to make the concentrate based foam to make the concentrate

"foam up"."foam up".



SpraySpray ((Air-Aspirating Nozzle)Air-Aspirating Nozzle)



Swirl nozzlesSwirl nozzles inject the liquid ininject the liquid intangentially, and it spirals into thetangentially, and it spirals into thecenter and then exits through thecenter and then exits through the

central hole.central hole.



Swirl nozzlesSwirl nozzles



The main function of a sprayThe main function of a spray

nozzle is to meter the liquid, thennozzle is to meter the liquid, then

atomize and then distribute into theatomize and then distribute into the

desired pattern.desired pattern.



Pressure is inversely proportional to area. P= F/A

Then why is this pressure decreased in convergent

nozzle, although there is a decrease in area?

nozzle1.ppt

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