ijetae_0416_55

International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 6, Issue 4, April 2016)

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Experimental and CFD Analysis of Vortex Tube Sumit Choudhary

1, Vijay Bhalerao

2, Vishal Jaiswal

3, Amit Vairagade

4, Prof. A. B. Bhane

5

1,2,3,4UG Student, Dept. of Mechanical Engineering , SND COE & RC, Yeola, Savitribai Phule Pune University, Maharashtra,

India 5Assistant Professor, Dept. of Mechanical Engineering, SND COE & RC, Yeola, Maharashtra, India

Abstract— The vortex tube is a simple device, having no

moving parts, which produces hot and cold air streams

simultaneously at its two ends from a single source of

compressed air. This paper describes the experimental study

on vortex tube made up of CPVC material which is cheaper

and lighter than conventionally used metals. This paper also

depicts the numerical simulation of the same by using CFD.

Literature review reveals investigations to understand the

heat transfer characteristics in a vortex tube with respect to

various parameters. There is no theory so perfect, which gives

the satisfactory explanation of the vortex tube phenomenon as

explained by various researchers.

Keywords— Air refrigeration, CFD, Cooling effect, CPVC,

RHVT, Spot cooling, Vortex tube.

I. INTRODUCTION

Vortex tube is a mechanical device operating as a

refrigerating machine without any moving part and no

chemical reaction. Vortex tube separates a flow of

compressed air into two streams simultaneously, one, a

current of air hotter than the inlet temperature & one

cooler, such a separation of the flow into region of low and

high total temperature is referred to as the temperature (or

energy) separation effect.

Generally Vortex tube can be classified into two types.

1) Counter flow vortex tube. (Referred as standard) 2)

Parallel or uni- flow vortex tube. The counter flow vortex

tube consist an entrance block of nozzle connection with a

cold orifice, a vortex tube (or hot tube) and a cone shape

valve. Counter flow Vortex tube means the direction of the

flow of free vortex and force vortex, that is outer flow and

inner flow are same. Compressed air is introduced into a

tube open at both ends through tangential flow inlets

positioned about a quarter of the tube's length away from

one end. A strongly swirling flow, vortex flow, results and

the gas proceeds along the tube. The outer regions of the

flow are found to be warmer than the inlet gas, while gas

towards the center of the experiences cooling.

The uni-flow vortex tube comprises an entrance block of

inlet nozzle, a vortex tube and a cone shape valve with a

central orifice. The operation of the uni-flow vortex tube is

similar to the operation of counter flow one. Uni-flow or

co-flow vortex tube means the directions of both the

vortices are same.

The uni-flow vortex tube is generally a less efficient

energy separator than the counter flow variety. Scientists

and pioneers found that counter flow type is efficient than

Uni-flow one.

But till date energy transfer mechanism in vortex tube is

not explained properly. Some pioneers have tried in their

own way to explain the magic but the explanations are not

supported by experimental results. The reason for the

difficulty in this work is the turbulence in the tube.

There are certain parameters, which contribute to the

performance of the vortex tube. The pioneers in this field

who conducted numerous experiments investigate these

parameters. A vortex tube is designed and fabricated and

several parameters are studied for the performance of the

vortex tube. The parameters are selected considering the

scope of the infrastructure and results are taken.

II. LITERATURE SURVEY

1. DESIGN OF VORTEX TUBE FOR SPOT COOLING

APPLICATIONS AS ALTERNATIVE ENERGY

SOURCES by Mr. Ambatkar S. D. & Prof. Purandare P.

S. This paper discusses about the mass flow rate on the

cold side of the vortex tube is controlled by orifice. This

paper describes the effect of variation of orifice diameter

on the performance of vortex tube is analyzed. The

parameters such as length, nozzle diameter are kept

constant. The performance is observed at various inlet

pressures. The cold side temperature, temperature

difference, refrigeration effect and coefficient of

performance of the tube are plotted against the ratio of

orifice diameter to tube diameter and against pressure.

The trend lines are sketch to observe the variation of

each parameter. The results are discussed with the help

of theoretical concepts.

2. MODELING, OPTIMIZATION &

MANUFACTURING OF VORTEX TUBE AND

APPLICATION A. M. Dalavi, Mahesh Jadhav, Yasin

Shaikh, Avinash Patil, IOSR Journal of Mechanical and

Civil Engineering (IOSR-JMCE) ISSN€ : 2278-1684,

ISSN(p) : 2320–334X,this article discusses about the

vortex tube is a simple device, having no moving parts,

which produces hot and cold air streams simultaneously

at its two ends from a source of compressed air.



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As such 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 perform experimentation.

3. OPTIMIZATION OF LOW PRESSURE VORTEX

TUBE VIA DIFFERENT AXIAL ANGLES OF

INJECTION NOZZLES by Pourmahmoud N.,

Jahangiramini A., Izadi A., IJE TRANSACTIONS A:

Basics Vol. 26, No. 10, (October 2013) 1255-1266. In

this paper, a Ranque–Hilsch Vortex Tube has been

optimized utilizing axial angles for nozzles. Effect of

nozzles angles on the flow behavior has been

investigated by computational fluid dynamics (CFD)

techniques. A finite volume approach with the standard

k–ε turbulence model has been used to carry out all the

computations. The dimensions of the studied vortex

tubes have been kept the same for all models and the

performance of machine was studied under 5 different

angles (β), namely 0, 2, 4, 6 and 8 degree adjusted to the

nozzles. Achieving a minimum cold exit temperature is

the main goal of this numerical research. The results

show that utilizing this kind of nozzle improves the

cooling capacity of device for most values of inlet mass

flow rates. Finally, some results of the CFD models have

been validated by the available experimental data which

show reasonable agreement, and other ones are

compared qualitatively.

4. A REVIEW OF COMPUTATIONAL STUDIES OF

TEMPERATURE SEPARATION MECHANISM IN

VORTEX TUBE, by Thakare H. R., Patil Y.R. and

Parekh A.D.., Bonfring International Journal of

Industrial Engineering and Management Science, Vol. 3,

No. 2, June 2013. This paper discusses about The

Ranque Hilsch Vortex Tube (RHVT) is a very simple

device well known for its phenomenal temperature

separation effect. With a single input of compressed gas,

the tube simultaneously produces two different streams

of gas – one being hotter and other being colder than

input gas. Over the years, different theories have

attempted to explain this effect without achieving any

universal agreement. Small size of RHVT presents

considerable difficulties towards predicting temperature,

pressure and flow field inside it. This is where

Computational Fluid Dynamics (CFD) analysis comes to

the aid of researchers. Many of researchers have

attempted such analysis using turbulence models such as

The Standard k-ε model, RNG k-ε model & Realizable

k-ε model, Large Eddy Simulation Technique (LES) etc.

This paper attempts to present a review of such recent

qualitative studies carried out on RHVT using CFD.

Care has been taken to explore diversified parameters

related to flow physics inside RHVT, instead of being

monotonous one. This review is expected to help future

researches in the related domain.

5. COMPUTATIONAL FLUID DYNAMICS ANALYSIS

AND EXPERIMENTAL INVESTIGATIONS OF

OPTIMUM GEOMETRY FOR THE COLD END

ORIFICE AND SNAIL ENTRY OF VORTEX TUBE

by Deshmukh B.S., Prof. Chhapkhane N.K., IOSR

Journal of Mechanical and Civil Engineering (IOSR-

JMCE) Volume 11, Issue 4 Ver. III (Jul- Aug. 2014), in

this paper presents an overview of recent research on

Ranque-Hilsch Vortex Tube (RHVT) with divergent

tube and snail entry, increase in nozzle number and

supply pressure leads to the rise of swirl / vortex

intensity & thus maximum energy separation in the tube.

The paper develops three dimensional flow domain

using Computational Fluid Dynamics (CFD) and this

CFD and experimental studies are conducted towards the

optimization of RHVT. The optimum cold end diameter

(dc), number of snail entry and optimum parameters for

obtaining the maximum hot gas temperature and

minimum cold gas temperature are obtained through

CFD analysis and validated through experiments

III. TEMPERATURE SEPARATION EFFECT

The Vortex Tube Creates two types of vortices: free and

forced. In a free vortex (like a whirlpool) the angular

velocity of a fluid particle increases as it moves toward the

Center of the vortex-that is, the closer a particle of fluid is

to the center of a vortex, the faster it rotates. In a forced

vortex, the velocity is directly, proportional to the radius of

the vortex-the closer the center, the slower the velocity. In

a vortex tube, the outer (hot) air stream is a free vortex. The

inner (cold) air stream is a forced vortex. The rotational

movement of the forced vortex is controlled by the free

vortex (hot air stream). The turbulence of both the hot and

cold air streams causes the layers to be locked together in a

single, rotational mass. The inner air stream flows through

the hollow core of the outer air stream at a slower velocity

than the outer air stream. Since the energy is proportional

to the square of the velocity, the cold air stream loses its

energy by heat transfer. This allows energy to flow from

the inner air stream to the outer air stream as heat creating a

cold inner air stream.



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IV. THE VORTEX TUBE PARAMETERS

In general, there are two-design feature associate with

vortex tube as vortex tube design is not yet standardized

because of some unrevealed phenomenon such as energy

transfer, nature of flow and other turbulent phenomenon.

1. Maximum temperature drop vortex tube design for

producing small quantity of air with very low temp.

2. Maximum cooling effect vortex tube design for

producing large quantity of air with moderate

temperature.

V. THE EXPERIMENTAL MODEL

Counter flow vortex Tube is used to study the Vortex

Tube phenomenon. Two holes were first made at tangent to

the CPVC (chlorinated polyvinyl chloride) tube. These two

holes acted as a vortex generator and created a vortex flow

when pressurized air is passed through them. Then circular

plastic disc of diameter being same as that of the inner tube

was drilled with a 5mm hole to make orifice. Then two

CPVC tubes were assembled together and attached to each

end of the small tube having nozzles to form cold end and

hot end tube. The conical valve was then made on a lathe

with a taper of 30º and was fixed at the hot end. The main

bush contains the orifice and nozzle bush. The conical

valve is placed at open end of the main tube the

thermocouple TH and TC are placed near the conical valve

and orifice plate to measure the hot and cold temperature of

air leaving the vortex tube. Air from compressor is fed to

main tube through nozzle. The air gets tangential entry in

the tube. As it expands it gets swirl. Air travel towards the

valve side end. The valve is having conical shape hence it

can be adjusted to control the mass flow rate of the air.

Because of the partial opening of the valve some of the air

escapes out and remaining is reflected back towards the

nozzle through the core of the tube. The orifice at another

end controls the back flow of air. Cold side pipe do not

have any effect on the performance of vortex tube but just

guide the cold mass flow.

Fig.1: Schematic diagram of Vortex Tube

The geometrical data of the vortex tube for fabrication

and CFD model is as mentioned below –

Nozzle Diameter 3 mm

Number of nozzles 2(tangential to inner

diameter)

Length of the tube 1000mm

Inner diameter of tube 25.4 mm

Orifice diameter 4 mm

The orifice diameter is chosen such that the ratio of

orifice diameter to tube diameter is within the range of 0.17

to 0.60 & the length of the tube is kept approx. 40 times the

diameter of the tube. The literature review shows that tube

works best in this range.

Fig 2: The Actual Setup Model of Vortex Tube

VI. THE RESULTS AND DISCUSSION

To analyze the performance experimentally, the inlet

pressure is varied and readings of cold end temperature

were taken for hot end valve opening of 25 % & 50%

respectively which is presented graphically as shown

below-

Graph 1: Value of Press. & Temp. for 75% Closed Valve



307

Graph 2: Value of Press. & Temp. for 50% Closed Valve

Fig. 3: Image of Sample Reading

Minimum temperature attained was -1.9˚C for 25%

valve opening at 4 bar pressure & 25.4˚C ambient

temperature.

VII. THE CFD ANALYSIS

Model of fluid cavity domain for CFD analysis was

prepared in Pro-E.

Fig. 4: Fluid Cavity Domain

Meshing and further analysis was done in ANSYS

Fluent.

Fig.5: Meshed Model

Fig.6: Temperature Plot

In CFD the minimum temperature attained was -4.7˚C

at 4 bar pressure & 25.4˚C ambient temperature.

VIII. ADVANTAGES AND APPLICATIONS

Advantages:

1) No moving parts, reliable, Maintenance free.

2) Instant cold air in environmental chamber.

3) Adjustable temperature

4) Interchangeable generators

5) No electricity or chemicals

6) Compact, light in weight.

7) Low cost application.

8) No coolant required.

9) No spark or explosion hazard.

10) Improve tool life and improve finish.

11) Maintenance free unit.



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Applications

The vortex tube could be applied easily where there is

ready availability of compressed air. Due to no moving

parts and maintenance free utilization it could be used

where safety matters much. It could be replacement for

refrigerants as it is absolutely eco-friendly. Some of the

applications are as follows:

Spot cooling: The vortex tube is presently much used in

spot cooling in factories where the atmospheric temperature

is high which could harm the tool and instruments, ex: near

furnaces.

Cutting tools: Vortex tube is used in machining operation

such as milling, turning, drilling, etc. While machining

friction is created. Due to poor conductance of heat than

fluids cutting tool get heated which have shorter life, hi

such systems these are in greater demand. This also helps

in improving the surface finishing and allows higher

cutting speed. It also reduces the lubrication problems.

Heater-cum-cooler use: It is best in use where cooling and

heating are simultaneously required .Such application are

in coffee houses and in castings where hot air could be used

for pre heating and cool for chilling of moulds.

Cooling of turbine blades: The cooling of blades by air

through radial holes in turbines are successfully used in air

crafts and marine application.

Air suits: It is not always advisable to use air condition

everywhere. The places where hazards are usual to happen

it is advised to use vortex tube. Such places could be in

coal mines and foundry workshops.

REFERENCES

[1] Ambatkar S. D. & Purandare P. S., “Design Of Vortex Tube For Spot Cooling Applications As Alternative Energy Sources”

[2] Domkundwar, “Refrigeration & Air Conditioning”, 5th edition, Tata McGraw-Hill.

[3] Dalavi A. M., Mahesh Jadhav, Yasin Shaikh, Avinash Patil,

“Modeling, Optimization & Manufacturing Of Vortex Tube And

Application”, IOSR Journal of Mechanical and Civil Engineering

(IOSR-JMCE) ISSN€ : 2278-1684, ISSN(p) : 2320–334X

[4] Pourmahmoud N., Jahangiramini A., Izadi A., “Optimization of Low

Pressure Vortex Tube via Different Axial Angles of Injection

Nozzles” IJE Transactions A: Basics Vol. 26, No. 10, (October 2013).

[5] Thakare H. R., Patil Y.R. and Parekh A.D., “A Review of Computational Studies of Temperature Separation Mechanism in

Vortex Tube”, Bonfring International Journal of Industrial

Engineering and Management Science, Vol. 3, No. 2, June 2013.

[6] Deshmukh B.S., Prof. Chhapkhane N.K., “Computational Fluid

Dynamics Analysis And Experimental Investigations Of Optimum

Geometry For The Cold End Orifice And Snail Entry Of Vortex Tube”,IOSR Journal of Mechanical and Civil Engineering (IOSR-

JMCE) Volume 11, Issue 4 Ver. III (Jul- Aug. 2014)

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