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FABRICATION OF VORTEX TUBE WITH PVC
A Project Report
Submitted in partial fulfillment of the requirements for the degree of
BACHELOR OF TECHNOLOGY
in
MECHANICAL ENGINEERING
by
B. Ravindranath 08191AO313
P. Prem Kumar 08191AO314
M. Narasimha Reddy 08191AO316
M. Naresh Reddy 08191AO318
MD. Abdul Wahid 08191AO361
DEPARTMENT OF MECHANICAL ENGINEERING
JNTUA COLLEGE OF ENGINEERING
PULIVENDULA – 516390
ANDHRA PRADESH – INDIA

JNTUA COLLEGE OF ENGINEERING, PULIVENDULA
DEPARTMENT OF MECHANICAL ENGINEERING
CERTIFICATE
This is to certify that the project entitled “FABRICATION OF VORTEX
TUBE WITH PVC” is being submitted by
B. Ravindranath 08191AO313
P. Prem Kumar 08191AO314
M. Narasimha Reddy 08191AO316
M. Naresh Reddy 08191AO318
MD. Abdul Wahid 08191AO361
In partial fulfillment of the requirement for the award of the Degree of
Bachelor of Technology in Mechanical Engineering to the Jawaharlal Nehru
Technological University Anantapur, Anantapur is a record of bonafied work
carried out by them under my guidance and supervision.
The results embodied in this project report have not been submitted to
any other University or Institute for the award of any degree.
-------------------------------- ---------------------------------
Mr. R.VISHNU VARDHAN REDDY Mr. D. R. SRINIVASAN
FACULTY GUIDE HEAD OF THE DEPARTMENT
MECHANICAL ENGINEERING MECHANICAL ENGINEERING

Contents
CONTENTS
CHAPTER Page No.
Acknowledgments……………………………………………………………. (i)
Abstract………………………………………………………………………… (ii)
List of Figures………………………………………………………………… (iii)
List of Tables………………………………………………………………….. (iv)
Nomenclature………………………………………………………………….. (v)
1. INTRODUCTION…………………………………………………………... 1
1.1 BACKGROUND 1
1.2 COMPONENTS OF VORTEX TUBE 2
1.3 WORKING OF VORTEX TUBE 3
1.4 ADVANTAGES OF VORTEX TUBE 4
1.6 DISADVANTAGES OF VORTEX TUBE 5
2. LITERATURE REVIEW……………………………………………….. 6
2.1 EXPLANATION GIVEN BY VAN DEEMETER 6
2.2 EXPLANATION GIVEN BY PARULEKAR 7
2.3 THEORY ON DYNAMICS OF VORTEX TUBE 8
3. TYPES OF VORTEX TUBE…………………………………………… 10
3.1 COUNTER FLOW VORTEX TUBE 10
3.2 UNI-FLOW VORTEX TUBE 10

Contents
3.3 CONICAL VORTEX TUBE 11
4. FABRICATION PROCEDURE…………………………………………… 12
4.1 PROCEDURE STEPS 12
4.2 VORTEX TUBE SET UP 15
4.3 EXPERIMENTATION 16
5. ANALYSIS OF VORTEX TUBE……………………………………… 18
5.1 THERMODYNAMIC ANALYSIS OF VORTEX TUBE 18
5.2 VORTEX TRANSFORMATION AND ENERGY TRANSFER 20
5.3 ANALYSIS OF VORTEX TUBE BASED ON FIRST LAW 21
5.4 ANALYSIS OF VORTEX TUBE BASED ON SECOND LAW 22
6. EXPERIMENTAL READINGS………………………………..…..… 25
6.1 FOR AIR COMPRESSER 25
6.1.1 SPECIFICATIONS OF THE AIR COMPRESSOR 25
6.1.2 ADIABATIC EFFICIENCY 25
6.1.3 CALCULATIONS 26
6.2 FOR VORTEX TUBE 26
6.2.1 READINGS FOR 27mm VORTEX TUBE 26
6.2.2 READINGS FOR 13.5mm VORTEX TUBE 27
6.2.3 CALCULATIONS 28

Contents
7. APPLICATIONS OF VORTEX TUBE……………………………..….. 30
7.1 AIR SUITS 30
7.2 VORTEX TUBE BASED REFRIGERATION 31
7.3 VORTEX COOLING SYSTEMS 32
7.4 AVIATION 33
7.5 PERSONAL AIR CONDITIONING 33
7.6 CUTTING TOOLS 34
7.7 SHRINK FITTING 34
7.8 COOLING OF GAS TURBINE ROTOR BLADES 34
7.9 LABORATORY SAMPLE COOLER 34
8. RESULTS AND DISCUSSIONS…………………………………… 35
8.1 GRAPHS 35
7. CONCLUSION………………………………………………………..….. 37
REFERRENCES……………………………………………………………. 38

Acknowledgements
i
ACKNOWLEDGEMENTS
It’s our privilege to express our gratitude to all, who helped us directly or
indirectly, in successfully completion of this Project.
The man who helped us a lot in times of troubles, and who helped us in
recovering from burn out problems is Prof. V.VENUGOPAL REDDY, Principal,
JNTUA College of Engineering, Pulivendula.
The man who wished our success, who shared our joy, who was with us
in times of troubles and helped us in finding solutions to many of our project
related problems, and the man who has to be complemented for our success
D. R. SRINIVASAN, Assistant Professor and Head of the Department,
Mechanical Engineering.
The elegant personality and the one who always supports our ideas and
guides us up-to-date about educational progress and our guide R.VISHNU
VARDHAN REDDY, Lecturer, Mechanical Engineering.
We thank the entire faculty, workshop technicians of Department of
Mechanical and our friends for their valuable comments, advices and
encouragement. Their constructive criticism helped us a lot in the course of
work.

Abstract
ii
ABSTRACT
The Ranque-Hilsch vortex tube has been used for many decades in
various engineering applications. Because of its compact design and little
maintenance requirements, it is very popular in heating and cooling processes.
Despite its simple geometry, the mechanism that produces the temperature
separation inside the tube is fairly complicated.
The vortex tube is a mechanical device that separates compressed air
into an outward radial high temperature region and an inner lower one. It
operates as a refrigerating machine with a simplistic geometry and no moving
parts. It is used commercially in cooling suits, refrigerators, airplanes, etc.
Other practical applications include cooling of laboratory equipment, quick
start up of steam power generators, natural gas liquefaction, and waste particle
separation in the gas industry.

List of figures
iii
LIST OF FIGURES
Fig. No Name Page No.
1.1 Schematic Diagram of Vortex Tube 2
1.2 Sectional view of Vortex Tube 3
2.1 3D Sectional view of Vortex tube 7
3.1 Counter flow Vortex tube 10
3.2 Uni flow Vortex tube 11
3.3 Conical Vortex tube 11
4.1 Sectional View of vortex tube 12
4.2 Vortex Chamber 13
4.3 Orifice Plate 14
4.4 Tangential Holes 14
4.5 Notch in Hot End Side 15
4.6 Line diagram of Experimental setup 16
7.1 Air suits of Vortex tube 30
7.2 Vortex tube Refrigerator & Experimental setup 31
7.3 Vortex tube Cooling System for a drill bit 32
7.4 Vortex tube Cooling AC Jacket 33
8.1 Pressure Vs Temperature Curve for 27mm Vortex
tube
35
8.2 Pressure Vs Temperature Curve for 13.5mm
Vortex tube
35

List of tables
iv
LIST OF TABLES
Table No Name Page No.
6.1 Adiabatic Efficiency 25
6.2 C.O.P of 27mm Vortex tube 27
6.3 C.O.P of 13.5mm Vortex tube 27

Nomenclature
v
NOMENCLATURE
mi Mass flow rate at inlet (kg/sec)
mc Mass flow rate at cold end (kg/sec)
mh Mass flow rate at hot end (kg/sec)
Tc Cold air temperature (0C)
Ti Inlet air temperature (0C)
Th Hot air temperature (0C)
Cp Specific heat of air at constant pressure (kJ/kgK)
hi Specific enthalpy of air at inlet (kJ/kg)
hc Specific enthalpy of air at cold side (kJ/kg)
hh Specific enthalpy of air at hot side (kJ/kg)
∆Tc Cold gas temperature difference (0C)
∆Th Hot gas temperature difference (0C)
µ Cold mass fraction
Pi Inlet pressure (bar)
Pa Atmospheric pressure (bar)
∆T’c Static temperature drop (0C)
∆Trel Relative temperature drop (0C)
ηab Adiabatic efficiency of the Vortex tube
ηac Adiabatic efficiency of the compressor
∆H Enthalpy change of system (kJ)
Q Heat exchanged between the system and its
surroundings (kJ)
∆Hc Enthalpy change of cold stream (kJ)
∆Hh Enthalpy change of hot stream (kJ)
∆S Total entropy change of system (kJ/K)
∆Sc Entropy change of cold stream (kJ/K)
∆Sc Entropy change of hot stream (kJ/K)

Nomenclature
vi
R Ideal gas constant (kJ/kg mol-K)
W Work done to compress the air (kJ)
T1 Compressor inlet temperature (0C)
T2 Compressor exit temperature (0C)

Introduction Chapter 1
1
CHAPTER 1
INTRODUCTION
1.1 BACKGROUND:
The vortex tube, also known as the Ranque-Hilsch vortex tube (RHVT)
is a device which generates separated flows of cold and hot gases from a
single compressed gas source. The vortex tube was invented in 1931 by
George Ranque, a French physics student, while experimenting with a
vortex-type pump that he had developed, and then he noticed warm air
exhausting from one end, and cold air from the other. Ranque soon forgot
about his pump and started a small firm to exploit the commercial potential
for this strange device that produced hot and cold air with no moving parts.
However, it soon failed and the vortex tube slipped into obscurity until 1945
when Rudolph Hilsch, a German physicist, published a widely read scientific
paper on the device.
Much earlier, the great nineteenth century physicist, James Clerk
Maxwell postulated that since heat involves the movement of molecules, we
might someday be able to get hot and cold air from the same device with the
help of a "friendly little demon" who would sort out and separate the hot
and cold molecules of air.
Thus, the vortex tube has been variously known as the "Ranque
Vortex Tube", the "Hilsch Tube", the "Ranque-Hilsch Tube", and "Maxwell’s
Demon". By any name, it has in recent years gained acceptance as a simple,
reliable and low cost answer to a wide variety of industrial spot cooling
problems.
When high-pressure gas is tangentially injected into the vortex
chamber through the inlet nozzle, a swirling flow is created inside the vortex
chamber. In the vortex chamber, part of the gas exists through the cold
exhaust directly, and another part called as free vortex swirls to the hot end,
where it reverses by the control valve creating a forced vortex moving from

2
the hot end to the cold end. Heat transfer takes place between the free end
and the forced vortices there by producing two streams, one hot stream and
the other is cold stream at its ends.
1.2 COMPONENTS OF VORTEX TUBE:
The vortex tube consists of the following parts.
1. Nozzle.
2. Diaphragms.
3. Control valve.
4. Hot air side.
5. Cold air side.
Fig. 1.1 Schematic Diagram of Vortex Tube
Chamber is a portion of nozzle in the same plane of nozzle and
facilitates the tangential entry of high velocity air stream into hot side.
Generally, the chambers are not of circular form, but they are gradually
converted into spiral form.
Hot side is cylindrical in cross section and is of different lengths, as
per designs Prof. Parulekar has proposed 3D as the effective length of hot
side for the efficient operation of the vortex tube.
Control valve obstructs the flow of air through hot side and it also
controls the quantity of hot air through vortex tube.
Hot Exit gas

3
Diaphragms called cold orifice, with a suitable sized hole in its center
is placed immediately to the left of the tangential inlet nozzle. The
compressed air is then introduced into the tube through this nozzle. The
tangential flow imparts a whirling or vortex motion to the inlet air, which
subsequently spirals down the tube to the right of the inlet nozzle. Conical
Control valve at right end of the tube confines the exit air to regions near the
outer wall and restricts it to the central portion of the tube from making a
direct exit. The central part of the air flows in reverse direction and makes
exit from the left end of the tube with sizeable temperature drop, thus
creating a cold stream. The outer part of the air near the wall of the tube
escapes through the right end of the tube and is found to have temperature
higher than that of inlet air. Cold side is a cylindrical portion through which
cold air is passed.
Fig. 1.2 Sectional view of Vortex Tube
1.3 WORKING OF VORTEX TUBE:
Compressed air is passed through the nozzle through air inlet. Here
air expands and acquires high velocity due to the nozzle. A vortex flow is
created in the chamber and air travels in spiral motion along the periphery
of the hot side. Then, the rotating air is forced down the inner walls of the
hot tube at speeds reaching 1,000,000 rpm.
The valve restricts this flow. When the pressure of the air near the
valve is made more than the outside by partly closing the valve, a reversed
axial flow through the core of the hot side starts from high-pressure region.

4
During this process, energy transfer takes place between reversed stream
and forward stream and therefore air stream through the core gets cooled
below the inlet temperature of the air in the vortex tube while the air stream
in forward direction gets heated. The cold stream is escaped through the
diaphragm hole into the cold side, while hot stream is passed through the
opening of the valve. By controlling the opening of the valve, the quantity of
the cold air and its temperature can be varied. There are several theories,
which give the physical explanation of the energy transfer from the colder
region to the hotter region.
1.4 ADVANTAGES OF VORTEX TUBE:
• Since air is used as the working medium, the minor leakages are
insignificant.
• Its design is quite simple and needs control of valves etc., for
appropriate functioning.
• No moving parts are used, the life of the vortex tube is expected to be
high and maintenance is almost nil.
• It is light in weight, quite compact, easy to cool even in a complicated
space, just by introducing air to the point under consideration since
a stream of cool air comes out of the vortex tube.
• Initial cost is low.
• No skilled attendant is required.
• Low maintenance cost and free instant cold air.
• Adjustable temperature according to environment condition.

5
1.5 DISADVANTAGES OF VORTEX TUBE:
• C.O.P is very poor compared to conventional refrigeration system.
• Limited capacity.

Literature Review Chapter 2
6
CHAPTER 2
LITERATURE REVIEW
No theory is so perfect, which gives the satisfactory explanation of
whimsical energy transfer in vortex tube.
2.1 EXPLANATION GIVEN BY VAN DEEMETER
The air enters the main tube through the nozzle and forms a free vortex.
Due to the centripetal acceleration, the vortex travels along the periphery of the
tube and when it reaches the throttle valve, the rotation almost ceases, so
there is a point of atmospheric pressure, a reverse axial flow starts. This flow
comes into contact with the free vortex, which is moving with the increasing
speed; therefore the axial stream forms a forced vortex. The energy required
maintaining the forced vortex in the reversed axial flow stream is supplied by
the free vortex at the periphery.
Therefore, there is flow of energy (momentum) from the peripheral layer
of air to the reversed axial flow stream at the axis The rotational velocity of the
free vortex at the periphery decreases gradually from the plane of the nozzle to
the plane of the valve, therefore there is a relative sliding between the two
adjacent air-planed, which are moving towards the valve. The result of this is a
continuous transfer of energy from the plane of the nozzle to that of the valve.
This gives the explanation why the heating of the air takes place as it proceeds
towards the valve. The transfer energy from the inner core (from the region of
forced vortex) to the periphery (into the region of free vortex) has not been
explained satisfactorily.

7
Fig. 2.1 3D Sectional view of Vortex tube.
2.2 EXPLANATION GIVEN BY PARULEKAR:
The air enters the tube tangentially and forms a free vortex. The vortex
travels along the wall due to centrifugal action. The air almost ceases to rotate
in the region of the valve.
The pressure near the valve is more than outside the diaphragm at the
other end, a reversal axial flow starts. This reversed flow comes in to contact
with the forward moving free vortex along the internal surface of the vortex.
The free vortex forces the axial stream to rotate as it rotates at a very high
speed. Thus an axial stream forms a forced vortex. The energy required to form
the forced vortex of the axial stream is supplied by the outer free vortex.

8
However, the flow of energy is in opposite direction but it is too small compared
with the energy transfer from the inner core to the outer periphery. The energy
transfer from the inner core to the outer periphery is explained below.
The turbulent mixing in the centrifugal field results in pumping of energy
from the low-pressure region at the axis to the high-pressure region at the
periphery. The energy is then transferred towards the valve in the form of
momentum as already explained above by Van Deemeter. This radial outflow
energy due to turbulent mixing is much more than that of the inward flow of
energy due to the formation of vortex, there is net transfer of energy radially
outward and towards the valve.
Thus a peripheral layer emerges a hot stream while axial layer emerges a
cold stream. For the insulated tube the energy carried away by the hot stream
is equal to the energy required by cold stream.
2.3 THEORY ON DYNAMICS OF VORTEX TUBE:
Compressed air is supplied to the vortex tube and passes through
nozzles that are tangent to an internal counter bore. These nozzles set the air
in a vortex motion. This spinning stream of air turns 90° and passes down the
hot tube in the form of a spinning shell, similar to a tornado. A valve at one end
of the tube allows some of the warmed air to escape. What does not escape,
heads back down the tube as a second vortex inside the low-pressure area of
the larger vortex. This inner vortex loses heat and exhausts through the other
end as cold air.
While one air stream moves up the tube and the other down it, both
rotate in the same direction at the same angular velocity. That is, a particle in
the inner stream completes one rotation in the same amount of time as a
particle in the outer stream. However, because of the principle of conservation
of angular momentum, the rotational speed of the smaller vortex might be
expected to increase. But in the vortex tube, the speed of the inner vortex

9
remains the same. Angular momentum has been lost from the inner vortex.
The energy that is lost show up as heat in the outer vortex. Thus the outer
vortex becomes warm, and the inner vortex is cooled.

Types of vortex tube Chapter 3
10
CHAPTER 3
TYPES OF VORTEX TUBE
Based on the positioning of the cold exhaust, there are two different
types of RHVT systems proposed by Ranque:
1) Counter flow vortex tube.
2) Uni- flow vortex tube.
3) Conical Vortex tube (By geometry).
3.1 COUNTER FLOW VORTEX TUBE:
When the cold exhaust is placed on the other side from the hot exhaust,
it is called “counter flow”. In this type of flow hot air and cold air flow in
opposite directions. Due to the heat exchange taking place between opposite
directions it is very efficient, hot air and cold air leave the tube from opposite
ends of the inlet.
Fig. 3.1 Counter flow Vortex tube
3.2 UNI-FLOW VORTEX TUBE:
When the cold exhaust and hot exhaust are placed at the same side, it is
named “uni-flow”. In this type of flow hot air and cold air flow in same
direction. Less heat exchange takes place uni-flow vortex tube hence it is less
efficient.

Types of vortex tube Chapter 3
11
Fig. 3.2 Uni flow Vortex tube
From the experimental investigation it was found that the performance of
the uni flow system is less than that of the counter flow system. So, most of the
time, the counter flow geometry was chosen.
3.3 CONICAL VORTEX TUBE:
Another type of geometry is the conical vortex tube. In 1961, Paruleker
designed a short conical vortex tube. By varying the conical angle of the vortex
tube, he found that the parameter L/D can be as small as 3.
Fig. 3.3 Conical Vortex tube

Fabrication Procedure Chapter 4
12
CHAPTER 4
FABRICATION PROCEDURE
4.1 PROCEDURE STEPS
Vortex cooling tube was built by using PVC pipe that has an inner diameter
of about 27 mm. From the formulae for the design of a "real vortex cooling
tube", that usually want the length of the hot end of the tube, to be about 45
times the diameter or in this case about 1215 mm. So this was the length in
the drawing below from the inlet nozzles to the cone block valve.
Fig. 4.1 Sectional View of vortex tube
In keeping with that thought, here are some other dimensions that are
followed in making the tube:
Tube Inner Diameter = 27 mm
Hot End Length = 45 x 27 = 1215 mm
Cold End Length = 10 x 27 = 270 mm

13
Orifice Size = 1/2 Tube Inner diameter or about 13.5 mm
Inlet Nozzles = 5 mm
Fig. 4.2 Vortex Chamber
In above figure "vortex chamber" is shown, this was where the Inlet nozzles
and the orifice were. To make this part of it, a piece of PVC tube cut to make
the hot end length and the cold end length to the dimensions above. Then a
thin piece of plastic was cut into a circle to the same diameter as the outside of
the 27 mm I.D. PVC tube. The outside diameter is about 33mm. A hole was
drilled into the plastic about 13.5 mm diameter to make the orifice. A 33 mm
PVC pipe tube coupling filed and sanded inside so that the PVC pipes will slide
all the way through. Then slide the hot and cold tubes into this coupling
capturing the cold orifice plate in between - no glue at this point.

14
Fig. 4.3 Orifice Plate
The above picture shows the cold end of the tube at the orifice plate. This
was the 13.5 mm diameter hole. Marking of hot and cold tubes as well as the
coupling is done, so it could take apart and put it back together in the same
orientation. Then it was taken apart and glued in the hot tube. 3 holes were
drilled through the coupling and into the tube at an angle (tangential), close to
the end of the hot tube.
Fig. 4.4 Tangential Holes

15
So now the two 6 mm cut pieces (blue in color as shown in fig 4.1) form the
ends of a chamber labeled. The Inlet air area with 60mm diameter pipe
coupling makes the outer part. All this is to have one inlet fitting for the air to
go into the Inlet air area and from there it can make it into the 3 Inlet Nozzles.
It is possible to have just one inlet nozzle or have five air lines into each hole
but the above method works better.
Now onto the other end of the vortex cooling tube a cone block is turned
down on lathe. A notch is designed in the tube to let the hot air out and drew
graduations on the cone to get an idea of adjustment.
Fig. 4.5 Notch in Hot End Side
4.2 VORTEX TUBE SET UP:
The main body was taken and from one end the cold tube is fitted. Through
the other side the diaphragm is placed upon which nozzle is placed. The nozzle
opening was made to set perfectly so that the opening comes in line with the
drilled hole, which is made, on top surface of the main body. Then the hot tube
was fitted on the other side such that there was no leakage of air. Through the
drilled hole the inlet tube is fitted which is connected to air compressor. The

16
other side of the hot tube is fitted with a control valve with control end and hot
end.
4.3 EXPERIMENTATION:
To study the effect of various parameters such as inlet pressure, orifice
diameter and L/D ratio on the performance of the vortex tube, an experimental
set up was prepared as per design described earlier. The vortex tube
components were made in a manner such that the geometry of the tube could
be changed from maximum temperature drop tube design to maximum cooling
effect tube design. The line diagram of the experimental set up is shown below.
Fig. 4.6 Line diagram of Experimental setup
The temperature of air at cold and hot ends was measured with digital as
well as analog thermometers to avoid errors. The air velocities were measured
made by an anemometer. The pressures were measured by the Bourdon tube
pressure gauges. All the instruments were calibrated before the measurements
were actually recorded. The operating parameters noted during the experiment
for each vortex tube design were:

17
• Air pressure near inlet to vortex tube (bar)
• Compressed air temperature (0C)
• Hot air temperature, Th ( 0C)
• Cold air temperature, Tc (0C)
The aim of the experiment is to study the variation of temperature at hot
end and cold end with respect to various working and geometrical parameters.
The parts i.e., inlet tube, main body (flange), cold tube, hot tube, nozzle,
diaphragm, control value are fitted one by one. The compressor is studied and
the pressures are maintained. The settled vortex tube is placed on the table
and the outlet of the compressor is attached to the inlet of the apparatus. First
the compressor is maintained at a pressure of 4bar and the air is allowed to
pass through the inlet and then we have to wait for 5 minutes. After this the
thermometers are placed at both the ends and the readings are noted as Th and
Tc. The temperature of inlet air is also noted down using a digital thermometer.
Then the compressor pressure is increased to 4bar and the readings are
taken in a similar manner. The procedure is followed up to 7bar. The readings
are tabulated as shown.

Analysis Of Vortex Tube Chapter 5
18
CHAPTER 5
ANALYSIS OF VORTEX TUBE
5.1 THERMODYNAMIC ANALYSIS OF VORTEX TUBE:
Vortex tube gets high pressure air from an air compressor through a
tangential nozzle. Assume suffixes i, h, c stands for inlet to the nozzle, hot
end and cold end, respectively then the mass and energy conservation of
control volume given by
Mass balance mi = mc + mh …..(i)
Steady flow energy balance mi.hi = mc.hc + mh.hh …..(ii)
Assuming the kinetic energies is negligible.
The cold gas temperature difference or the temperature drop of the cold air
tube is defined as ∆Tc = Ti−Tc.
The hot gas temperature difference or the temperature raise of the hot air
tube is defined as ∆Th = Th−Ti.
If the system is isentropic then the heat lost by the cold stream is equal to
heat gained by hot stream.
mc (Ti – Tc) = mh (Th – Ti) = (mi - mc).(Th – Ti) …..(iii)
Ti – Tc = [
௠೔
୫ౙ
-1].(Th - Ti) = (
ଵ
ఓ
-1).(Th – Ti)
Where µ is the ratio of cold air to the air supplied, called as cold mass
fraction.
From equation (iii) we get.
µ(Ti – Tc) = (1 – µ).(Th – Ti)
µ[(Ti – Tc) + (Th – Ti)] = (Th – Ti)
µ = (Th – Ti)/ [(Ti – Tc) + (Th – Ti)] = ∆Th/(∆Th + ∆Tc)
µ =
௠೎
୫౟
- …..(iv)

19
if the process had undergone an isentropic expansion from inlet pressure Pi
to atmospheric pressure Pa at the cold end then the static temperature drop
due to expansion is given by
∆T’c = Ti – T’c = Ti[1-(Pa/Pi)(γ-1)/γ] …..(v)
The temperature drop occurred in Vortex tube is ∆T’c. The ratio of ∆Tc to ∆T’c
is called Relative Temperature drop
∆Trel = ∆Tc/∆T’c …..(vi)
The product of µ and ∆Trel represents the adiabatic efficiency of the Vortex
tube because it is defined as
ηab =
୅ୡ୲୳ୟ୪ ୡ୭୭୪୧୬୥ ୥ୟ୧୬ୣୢ ୧୬ ୴୭୰୲ୣ୶ ୲୳ୠୣ
େ୭୭୪୧୬୥ ୮୭ୱୱ୧ୠ୪ୣ ୵୧୲୦ ୟୢ୧ୟୠୟ୲୧ୡ ୣ୶୮ୟ୬ୱ୧୭୬
ηab = (mc∆TcCp)/(mi∆T’cCp) = µ∆Trel = µ. (∆Tc/∆T’c)…..(vii)
ηab = [∆Th/(∆Th + ∆Tc)]* (∆Tc/∆T’c)
The C.O.P of the vortex tube is defined as the ratio of the cooling effect to the
work input to the air compressor.
Cooling effect =mc∆TcCp
Work input to air compressor = (CpmiTi)[(Pi/Pa)(γ-1)/γ-1]/ηac
Where ηac is the adiabatic efficiency of the compressor.
C.O.P =
େ୭୭୪୧୬୥ ୣ୤୤ୣୡ୲
୛୭୰୩ ୧୬୮୳୲
= [(mc∆TcCp).ηac]/ (CpmiTi)[(Pi/Pa)(γ-1)/γ-1]
C.O.P = µ(∆Tc. ηac)/{Ti[(Pi/Pa)(γ-1)/γ-1]} …..(viii)
Substituting the value of Ti from equation (v), in equation (viii), we get
{ µ(∆Tc. ηac)}
C.O.P = ______________________________________
{( ∆T’c/[1-(Pa/Pi)(γ-1)/γ]) [(Pi/Pa)(γ-1)/γ-1]}

20
{µ. (∆Tc/∆T’c) ηa}{[(Pi)(γ-1)/γ -(Pa)(γ-1)/γ].(Pa)(γ-1)/γ}
C.O.P = _____________________________________________
{[(Pi)(γ-1)/γ -(Pa)(γ-1)/γ]. (Pi)(γ-1)/γ}
C.O.P = µ. (∆Tc/∆T’c) ηac. [(Pa/Pi)(γ-1)/γ] …..(ix)
Substituting the value of µ (∆Tc/∆T’c), from equation (vii), we get
C.O.P = ηab. ηac. [(Pa/Pi)(γ-1)/γ]
It has been observed that the value of ηac is always considerably
small, therefore the C.O.P of the vortex tube will also be very small of the
order of 0.15 to 0.25 under normal operating conditions.
5.2 VORTEX TRANSFORMATION AND ENERGY TRANSFER:
The air enters the vortex tube tangentially and forms a free vortex.
Due to the centrifugal action, the vortex travels along the wall. As a result a
result of the obstruction of the valve, the air almost ceases to rotate in the
region of the valve. As the pressure at the valve is more than that outside
the diaphragms at the other end a reversed axial flow starts. This received
flow comes in contact with the forward moving free vortex along the internal
surface of the vortex. As the vortex is rotating at a very high speed, it forces
the axial stream to rotate. Thus the axial stream forms a forced vortex. The
external energy required by the forced vortex is supplied by the free vortex.
Therefore, there is a flow of energy in the opposite direction as explained
here after much exceeds this inward flow.
The air in the transverse plane through the nozzle has the highest
rotational speed, which decreases gradually from the nozzle towards the
valve, where it is almost negligible. There is therefore a relative sliding
between various transverse planes. A last moving plane tries to speed up the
adjoining plane by imparting to the lower plane some of its momentum. In
this way, there is a continuous flow of energy from the plane of the nozzle to
the valve.

21
As mentioned by Shultz-Gaunow and others, turbulent mixing in the
centrifugal fields results in pumping of energy from the low pressure region
at the axis to the high pressure region at the periphery. The energy is then
transferred towards the valve in the form of momentum transfer mentioned
above and also due to the mass itself shifting towards the valve.
Thus, there is a net pumping of energy from the axial region near the
diaphragms to the region near the valve. The stream flowing past the valve
carries this energy with it. Both the hot and cold stream starts from the
same point. The stagnation point forms at the valve.
At this point both the streams have the same temperature; however
the reversed stream rejects some energy and is cooled while the other
stream leaves at the temperature of stagnation point, which is much higher
than the inlet temperature. For an insulated tube the extra energy carried
away by the hot stream is equal to the energy rejected by the cold stream.
5.3 ANALYSIS OF VORTEX TUBE BASED ON FIRST LAW:
An examination of the system at steady state indicates that from the
First Law of Thermodynamics
∆H= Q
Where ∆H is the system enthalpy change and Q is the heat exchanged
between the system and its surroundings. Let’s assume that Q is
approximately zero even though the cold tube may have frost on it and the
hot tube is very warm (remember that Q is the total heat exchanged). If this
is the case then
∆H= ∆Hc+ ∆Hh= 0
Where ∆Hc is the enthalpy change of cold stream and ∆Hh is the
enthalpy change of hot stream. Assuming the air as an ideal gas, the total
enthalpy change can be written as

Analysis Of Vortex Tube
∆H= m
The inlet and hot outlet mass flow rates are measured through a float
type meter (restriction of cold tub
operating properly in most cases). The mass flow rate from the cold tube is
obtained by applying the conservation of mass principle to the whole
system.
5.4 ANALYSIS OF VORTEX TUBE BASED ON SECOND LAW:
An examination of the system at steady state indicates that from the
Second Law of Thermodynamics. Assuming the process as reversible and
adiabatic then
∆S =
Where ∆S is total entropy change, q is heat transfer and T is absol
temperature. The actual entropy change of the control volume at steady
state is
∆S = ∆
Where ∆Sc and ∆Sh
portion of entering air which leaves the cold tube, and the portion of
entering air which leaves the hot tube, respectively.
For an ideal gas with constant specific heat, the entropy change can
be written as
∆S =
୫ౙ
୫౟
ቀC௣ ln
Where the subscripts i, c and h are respectively inlet stream, cold
stream and hot stream and R is the ideal gas constant. Notice that in reality
the vortex tube process is irreversible so
22
H= mcCp (Tc – Ti) + mhCp (Th – Ti) = 0
type meter (restriction of cold tube to measure flow will prevent device from
.4 ANALYSIS OF VORTEX TUBE BASED ON SECOND LAW:
examination of the system at steady state indicates that from the
S = = 0
S is total entropy change, q is heat transfer and T is absol
∆Sc + ∆Sh
h are the entropy change from entrance to exit of the
ch leaves the hot tube, respectively.
ln
୘೎
୘౟
൅ ܴ ln
୔౟
୔ౙ
ቁ ൅
୫౞
୫౟
ቀC௣ ln
୘೓
୘౟
൅ ܴ ln
୔౟
୔౞
ቁ
here the subscripts i, c and h are respectively inlet stream, cold
the vortex tube process is irreversible so ∆S should be greater than zero.
Chapter 5
e to measure flow will prevent device from
.4 ANALYSIS OF VORTEX TUBE BASED ON SECOND LAW:
examination of the system at steady state indicates that from the
S is total entropy change, q is heat transfer and T is absolute
are the entropy change from entrance to exit of the
ቁ
here the subscripts i, c and h are respectively inlet stream, cold
S should be greater than zero.

23
Since the appearance of a cold (or hot) effect upon the pipe wall
without moving parts would tempt to consider this device as competition for
a refrigerator (or heat pump), it is instructive to estimate its coefficient of
performance (COP). Focusing on the cooling effect that can be achieved by
placing the cold pipe within an enclosure, the COP can be calculated by
C. O. P =
∆H௖
W
Where ∆Hc is obtained from
∆Hc = mcCp (Ti – Tc)
∆Hc is equal to the heat that is transferred to the cold stream through
the cold pipe wall (like a heat exchanger) from some source (like the cold box
in a refrigerator) and W in the present case is the work done to compress the
air from atmospheric pressure and temperature to the inlet conditions of the
tube. Assuming reversible compression (isentropic, minimum work), W then
obtained from:
W =
௠೔ோሺ்మି ்భሻ௡
௡ିଵ
……(x)
Where T2 is the compressor exit temperature, and T1 is the compressor inlet
temperature (Reversible, Polytropic process; n=1.4). If we consider a
complete system, P1 and T1 are the atmospheric pressure and temperature,
P2 and T1 are the compressor exit conditions,
ቀ
௉మ
௉భ
ቁ
ംషభ
ം
=
்ଶ
்ଵ
…….(xi)
After the air is compressed, it is kept in the high pressure tank where
then it cools down to the atmosphere temperature T1, so the inlet
temperature of the sonic nozzle, Ti, is equal to T1. By noting that
Rቀ
୬
୬ିଵ
ቁ = C୮

24
Equation (x) can be simplified to
W=m୧C୮(T2-Ti)
with T2 calculated from Eq. (xi). This is an ideal work value so it is less than
the actual work needed to drive the compressor.
The comparison between vortex tube COP with the conventional
refrigeration COP will show that unless high pressure air is inexpensive or
the vortex tube simplicity is more important than the cost of operation, the
conventional system is better.
The refrigeration effect of the vortex tube is simply equal to ∆Hc,
Qc= mcCp (Tc – Ti)

Experimental Readings Chapter 6
25
CHAPTER 6
EXPERIMENTAL READINGS
6.1 FOR AIR COMPRESSER:
6.1.1 SPECIFICATIONS OF THE AIR COMPRESSOR:
Compressor H.P 3HP
No of cylinders 2
Diameter L.P cylinder 0.07m
Diameter H.P cylinder 0.05m
Stroke length 0.085 m
Number of stages 2
Coefficient of discharge 0.62
Orifice diameter 0.022 m
6.1.2 ADIABATIC EFFICIENCY:
Delivery
pressure
(bar)
Speed,
N(rpm)
Time
for 10
rev
(Sec)
Theoretical
volume
flow rate
V1
(m3/sec)
Energy
input
(kW)
Adiabatic
Work (J)
Adiabatic
efficiency
7 882 86 9.6x10-3 5.23 0.025x105 0.4811
6 886 87 9.6x10-3 5.21 0.022x105 0.4342
5 888 87 9.6x10-3 5.12 0.019x105 0.3837
4 894 88 9.6x10-3 5.01 0.016x105 0.2492
Table 6.1 Adiabatic Efficiency

26
6.1.3 CALCULATIONS:
Atmosphere pressure P1 = 1.013bar
Delivery pressure P2 = 6bar
Energy input =
= 5.21661kW
Theoretical volume V1 =
= 9.655x10-3 m3/sec
Adiabatic Work Done = P1 V1 [(p2/p1) (‫ץ‬-1/‫ץ‬)-1]
= 0.02265x105 J
Adiabatic Efficiency = (Adiabatic Work Done)/ (Energy Input)
= 0.4342
6.2 FOR VORTEX TUBE:
For different length to diameter (L/D) of hot pipe with Orifice of different
diameter (d) at different input pressure.
6.2.1 READINGS FOR 27mm VORTEX TUBE
Orifice diameter = 13.5mm
Length = 1215mm
L/D ratio = 45
Hot tube hole diameter = 27mm,
Inlet Temperature of Air = 300C

27
Table 6.2 COP of 27mm Vortex tube
6.2.2 READINGS FOR 13.5mm VORTEX TUBE
Orifice diameter = 6.725mm Length = 607.5mm L/D ratio = 45
Hot tube hole diameter = 13.5mm, Inlet Temperature of Air = 300C
Table 6.3 COP of 13.5mm Vortex tube
Press
ure
Pi(bar)
Cold
Temp
Tc(0C)
Hot
Temp
Th(0C)
Differen
ce
∆T= Th-
Tc
(0C)
Cold
Temperat
ure Drop
∆Tc(0C)
Hot
Temperat
ure Drop
∆Th(0C)
Cold
mass
Fracti
on
µ
Adiabat
ic
Efficien
cy
C.O.P
7 -0.02 50.3 50.05 30.02 20.3 0.403 0.93 0.22
6 2.3 44.6 42.3 27.7 14.6 0.345 0.79 0.20
5 4.1 40.8 36.7 26 10.1 0.293 0.681 0.16
4 6.4 35.5 29.1 23.6 5.5 0.189 0.450 0.15
Press
ure
Pi(bar)
Cold
Temp
Tc(0C)
Hot
Temp
Th(0C)
Differen
ce
∆T= Th-
Tc
(0C)
Cold
Temperat
ure Drop
∆Tc(0C)
Hot
Temperat
ure Drop
∆Th(0C)
Cold
mass
Fracti
on
µ
Adiabat
ic
Efficien
cy
C.O.P
7 6.5 41.6 35.1 23.5 11.6 0.331 0.60 0.168
6 9.9 37.4 27.5 20.1 7.4 0.269 0.452 0.146
5 12.5 34.5 22 17.5 4.5 0.204 0.325 0.125
4 16.3 30.6 14.3 13.7 2.6 0.150 0.211 0.111

28
6.2.3 CALCULATIONS:
Specimen calculations for the inlet pressure of air, Pi = 6 bar
OBSERVATIONS:
1. Atmospheric pressure, Pa = 1.013bar
2. Inlet pressure of air, Pi = 6bar
3. Inlet temperature of air, Ti = 300C
4. Cold air exit temperature, Tc = 2.30C
5. Hot air exit temperature, Th = 44.60C
CALCULATIONS:
1. Cold drop temperature ∆Tc = Ti - Tc = 30-2.3
∆Tc = 27.70C
2. Hot raise temperature ∆Th = Th – Ti = 44.6-30
∆Th = 14.60C
3. Temperature Drop at the two ends ∆T = Th - Tc = 44.6-2.3
∆T = 42.30C
4. Cold mass fraction µ =
µ = 0.3451
5. Static Temperature Drop Due To Expansion
∆T’c = Ti – T’c = Ti[1-(Pa/Pi)(γ-1)/γ]
= 11.9520C
6. Relative Temperature Drop ( ∆Trel ) = ∆Tc/( ∆T’c )
= 2.317

29
7. Adiabatic Efficiency ( ηab ) =
ηab = x ∆Trel
= 0.3451x2.317
= 0.79
8. Coefficient of Performance ( C.O.P ) of Vortex Tube
C.O.P = ηab. ηac. [(Pa/Pi)(γ-1)/γ]
= 0.201

Applications Of Vortex Tube Chapter 7
30
CHAPTER 7
APPLICATIONS OF VORTEX TUBE
The use of vortex tube for small capacity applications is always
justified if the compressed air is readily available. The following few specific
applications of vortex tube are described below.
7.1 AIR SUITS:
A British company is manufacturing one piece air-cooled suits. These
suits are used by the operators entering vessels, tanks and pits where it is
dangerous due to the concentration of toxic vapors, fumes or dust. It is
commonly used by the workers working in the coal mines and foundries. It
is not always economical to condition the hot place like foundry where the
heat load is considerably large. The only economical way is to air-condition
the operators working near the hot places.
Fig. 7.1 Air suits of Vortex tube
Presently, the largest single use is a cooling unit for protective
clothing and helmets for such jobs as sandblasting, welding and handling
toxic materials. These garments can be cooled simply by connecting a vortex
tube to an airline and attaching it to the suit.

31
The air in the air suit is supplied to the mask and the top half of the
suit to maintain the normal body temperature. The air supply to the unit
can be cooled or warmed by the vortex tube. The supply of air can also be
adjusted quickly and easily. The safety and comfort provided by such a suit
can result in a very considerable saving in cost because the operator has to
work a long time under unpleasant conditions. This is an ideal application
of vortex tube, where lightness, compactness and simplicity are of prime
importance.
7.2 VORTEX TUBE BASED REFRIGERATION:
Refrigeration of food and medicine is an extensive problem. Fishing
communities living on the coast line are also dependent on cold storage
facilities for storing a day's catch. Usually conventional cold storage rooms
are expensive for a local fisherman to afford. Conventional refrigerators are
expensive to buy for an average person. Another important problem is
transport of medicines, specifically vaccines from one place to another.
Several vaccines require storage at low temperatures. Thus the distance a
medicine can be delivered through road is very limited. Thus many remote
areas do not receive vaccines at local hospitals.
Fig. 7.2 Vortex tube Refrigerator& Experimental setup.

Applications Of Vortex Tube
7.3 VORTEX COOLING SYSTE
The compact size of
for small enclosures. Powered by compressed air
chilled air without refrigerants or moving parts. These coolers provide
exceptional reliability with minimal maintenance in even the most
Another important vortex tube application is in cooling
enclosures. This use is commonly fo
temperature (near furnace) can be harmful to the tools and instruments,
particularly electronic devices. Many enclosure coolers are used on motor
controls. In hot weather, motor controls were often trip
motor is not overloaded. This nuisance tripping can represent a major
problem in a large plant on a hot day. Enclosure coolers solve this problem
by air-conditioning the panel boxes.
Fig. 7.3 Vortex tube Cooling System for a drill bit
There is no doubt that the number of applications of vortex tube is
increasing and will probably continue to increase. The availability of
compressed air is an important factor in determining whether a vortex tube
is in good position.
32
VORTEX COOLING SYSTEMS:
The compact size of vortex cooling systems make them ideally suited
for small enclosures. Powered by compressed air, vortex tube
exceptional reliability with minimal maintenance in even the most
enclosures. This use is commonly found in factories where high ambient
controls. In hot weather, motor controls were often trip-out even though t
conditioning the panel boxes.
Vortex tube Cooling System for a drill bit
Chapter 7
cooling systems make them ideally suited
, vortex tube generate
exceptional reliability with minimal maintenance in even the most.
und in factories where high ambient
out even though the
Vortex tube Cooling System for a drill bit

33
7.4 AVIATION:
The cabins of high-speed gas turbine powered aero planes are cooled
with the use of bootstrap air-cycle. The vortex tube can also be used for the
same purpose with less efficiency because more air would have to be bled-off
from the compressor at high pressure.
Compared with bootstrap cycle for the same cooling capacity. The use
of vortex tube would result in overall reduction in weight, which is of prime
importance. The use of vortex tube in military aircraft may have a marked
advantage over all other systems as a small cockpit is cooled.
7.5 PERSONAL AIR CONDITIONING:
Fig. 7.4 Vortex tube Cooling AC Jacket.
Inside the PAC, a vortex tube spins the supplied compressed air,
separating it into hot and cold airstreams. The cold air stream is delivered to
the vest through a ducting tube, while the hot air exits out the side of the
PAC unit. The low-pressure cold air flows into the diffuse-air Vest's
perforated inner lining, which distributes the refrigerated air over the upper
body. Unfolding the collars of the vest will reveal air holes to cool the neck
and face.

34
7.6 CUTTING TOOLS:
Many vortex tubes are used to cool machining operations over small
area. For example, many tubes are used to cool machining operations such
as drilling, milling, turning and reclaiming. As a rule those materials which
are difficult to machine are poor conductors of heat. Therefore, machining
operations heat does not readily flow away from the machining site and the
tool overheats, causing excessive tool wear. Even a few degrees of tool
cooling by vortex tube can increase the tool life, improves surface finish and
allows higher cutting speeds. Some materials are best cut without any
lubrication.
7.7 SHRINK FITTING:
Shrink fitting usually requires refrigeration for a short period. Most
factories have ring main air suppliers and vortex tubes could be connected
at numerous points in the ring main where it is required.
7.8 COOLING OF GAS TURBINE ROTOR BLADES:
The research is going on from last 25 years to find out effective and
efficient method for cooling the gas turbine rotor blades. The cooling of
blades by passing the air through number of radial holes provided for the
purpose is successfully used in gas turbines used for aircraft and marine
purposes. The cycle efficiency and specific output both can be improved with
the same quantity of air but at a lower temperature which can be made
available with the help of vortex tube. The compressed air can be supplied
from the main compressor.
7.9 LABORATORY SAMPLE COOLER:
Vortex Corporation USA in which cooled air from vortex tube is
circulated and the temperature inside is maintained below atmosphere
develops rectangular model type box. A sample, which is to be cooled, is
kept in this box for a specified time. This model is very useful in laboratories
and research institutions.

Results and discussions Chapter 8
35
CHAPTER 8
RESULTS AND DISCUSSIONS
8.1 GRAPHS
Fig. 8.1 Pressure Vs Temp Curve for 27mm Vortex tube
Fig. 8.2 Pressure Vs Temp Curve for 13.5 mm Vortex tube
0
10
20
30
40
50
60
4 5 6 7
Temperature(0C)
Pressure(bar)
Hot
Cold
Difference
0
5
10
15
20
25
30
35
40
45
4 5 6 7
Temperature(0C)
Pressure(bar)
Hot
Cold
Difference

Results and discussions Chapter 8
36
• The highest COP is obtained at 7 bar for 27mm vortex tube and the value
is 0.22.
• The lowest cold temperature for 27mm vortex tube is -0.02°C at 7 bar
and for 13.5mm vortex tube is 6.5°C at 7 bar.
• The highest hot temperature for 27mm vortex tube is 50.3°C at 7 bar and
for 13.5mm vortex tube is 41.6°C at 7 bar.
• Cold mass fraction obtained is better for the 27mm vortex tube than the
13.5mm vortex tube.
• The maximum of 50.05°C difference between hot and cold ends
temperature for 27mm vortex tube and maximum of 35.1°C difference
between hot and cold ends temperature for 13.5mm vortex tube.

Conclusion Chapter 9
37
CHAPTER 9
CONCLUSION
Literature review reveals that there is no theory so perfect, which gives
the satisfactory explanation of the vortex tube phenomenon as explained by
various researchers. Therefore, it was thought to carryout experimental
investigations to understand the heat transfer characteristics in a vortex tube.
The effect of the pressure on the cold temperature drop, hot temperature
raise, and COP of the Vortex tube are analyzed and the results obtained by this
technique have led to the following conclusions.
1. The Cold drop temperature ∆Tc increases with increase in inlet air
pressure.
2. The Hot temperature raise ∆Th increases with increase in inlet air
pressure.
3. The COP of the vortex tube increases with increase in inlet
pressure.
4. The optimum end gate valve opening gives the best performance.
5. The effect of nozzle design is more important than the cold orifice
design in getting higher temperature drops.
6. The surface finish of the nozzle and the hot tube plays a great role
in the performance of the vortex tube, good surface finish leads to
the better performance. So, care to be taken while fabrication of
the parts to obtain to get good surface finish.

References
38
REFERENCES
1. G J Ranque. Experiments on Expansion in a Vortex with Simultaneous
Exhaust of Hot and Cold Air. Le Journal De Physique, et le Radium (Paris), vol
4, June 1933, pp 1125-1130.
2. R Hilsch. The use of the Expansion of Aires in a Centrifugal Field as a
Cooling Process. Review of Scientific Instruments, vol 13, February 1947, pp
108-113.
3. S.C Arora and S. Domkundwar, A course in refrigeration and air
conditioning, Dhanapat Rai & Sons Publications, Seventh edition.
4. C D Fulton. Ranque Tube. Journal of the ASRE, Refrigeration Engineering,
vol 58, May 1950, pp 473-479.
5. G W Scheper ( Jr). The Vortex Tube Internal Flow Data and a Heat Transfer
Theory. Journal of the ASRE, Refrigeration Engineering, vol 59, October 1951,
pp 985-989.
6. J P Hartnett and E R G Eckert. Experimental Study of the Velocity and
Temperature Distribution in a High Velocity Vortex Tube Flow. Transactions of
ASME, vol 79, May 1957, pp 751-758.
7. B Parulekar. The Short Vortex Tube. Journal of Refrigeration, vol 4, 1961,
pp 74-80.
8. R B Aronson. The Vortex Tube: Cooling with Compressed Air. Journal of
Machine Design, December 1976, pp 140-143.

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