RHVT SYNOPSIS

8/17/2019 RHVT SYNOPSIS

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INTRODUCTION

The Ranque-Hilsch vortex tube is a mechanical

device operating as a refrigerating machine

without any moving parts, by separating a

compressed gas stream into a low total

temperature region and a high one. Such a

separation of the ow into regions of low and high

total temperature is referred to as the temperature

!or energy" separation e#ect. $t generates cold and

hot air stream from the source of compressed air. $tcontains the parts inlet no%%le, vortex chamber,

cold-end ori&ce, hot-end control valve and tube.

'hen high pressure gas is tangentially in(ected

into the vortex chamber through the inlet no%%les,

a swirling ow is created inside the vortex

chamber. $n the vortex chamber, part of the gas

swirls to the hot end and another part existthrough the cold end directly, part of the gas in the

vortex tube reverses for axial component of the

velocity and move from the hot end to the cold

end. )t the hot end, the air escapes with higher

temperature, while at the cold end, the air has

lower temperature compared to that of the inlet

temperature pass through the ori&ce. There aretwo types of vortex tube ow i.e. counter ow and

parallel ow. )ccording to our *nowledge there is

lac* information regarding parallel ow vortex

tube. )ll the references mentioned above refer to


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the counter ow vortex tube. $t can produce cold

air as low as -+ and hot air as high as /0,

ow rates from /1 to +/+1 S234 !Standard 2iters

per 4inutes" and refrigeration e#ect up to /50*cal6hr.

HISTORY

The concept of vortex tube was discovered byRanque !788" and later developed by Hilsch

!7+0". $n memory of their contribution the 9ortex

tube is also *nown as Ranque-Hilsch vortex tube

!RH9T". )nalytical study on vortex tube was

discussed by 2ay !757". Soni and Thomson !705"

gave the expressions for designing vortex tube.

Hartnet and :c*ert !750" investigated with largesi%e vortex tube. ;ao !/?. )r(omandi and

@enpeng !/


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LITERATURE REVIEW

The generation of two streams at the di#erenttemperatures from the vortex tube was discovered

in 78< by ;eorges B. ranque. Since then it has

been *nown as the Ranque e#ect. Ranque

proposed the compression and expansion e#ects

as the underlined reasons for the process of

temperature separation in vortex tube C, /D.

Since the discovery of the vortex tube it has beeninvestigated experimentally theoretically and

numerically.

$n ?ecember /


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San*ar Ram T. and )nish Ra( A. C/


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• To understand ow behavior inside the vortex

tube

• To develop and test acceptable hypothesis for

energy separation in vortex tube• To improve the oeKcient of performance of

vortex tube

CONCEPT

)ccording to C,/D the hypothesis for temperature

separation in vortex tube is as follows G

The vortical ow generated by tangential in(ection

moves to the hot end and peripheral part escapes

from the hot exit at a temperature higher than the

inlet temperature. )s reported in C/,5D , the

irrotational vortex near the hot end indicates an

increase in the centrifugal force on the central

swirling ow which leads to an outward movement


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of the central uid towards the tube wall. Hence,

on its way moving to the cold end, the central ow

spreads outward, mixes with the peripheral ow

and then turns bac* to the hot end again. Thisspeci&c ow structure was &rst observed in C/D and

named as Multi-circulation. because of the

strong swirling ow in the rear part of the tube, a

substructure could be found within the primary

multi-circulation, which is presented by smaller

circles in the hot region. The temperature of the

peripheral ow rises mainly due to the partialstagnation and mixing induced by the ow

structure of the multi-circulation. The outward

movement of the central ow leads to its mixture

with the peripheral ow and formation of the multi-

circulation. The inner part of the ow moves

towards hot end and turns bac* in the front part of

the tube. The ow in this region expands due to the

lower pressure in the central part of the tube and

then it escapes from the cold no%%le at a

temperature than the supplied air.


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Methodology

1] design - In general, there are two design features associated

with a vortex tube, namely, maximum temperature drop

vortex tube design for producing small quantity of air with

very low temperatures and maximum cooling effect vortex

tube design for producing large quantity of air with moderate

temperatures. he parameters investigated in the study, to

understand their inter-relationships and their effect on the

performance of the vortex tube are!

"o##le diameter

$old orifice diameter

%ength of the tube

&rea at the hot end

RHVT SYNOPSIS

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