Hr2413591363

Rahul B Patel, Dr. V. N. Bartaria , Tausif M Shaikh / International Journal of Engineering
Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.1359-1363
A Review On Exprimental & Numerical Investigation Of
Ranque Hilsch Vortextube
Rahul B Patela , Dr. V. N. Bartariab , Tausif M Shaikhc

Abstract-
The vortex tube or Ranque–Hilsch inlet pressure and speed. Pressure difference occurs
vortex tube is a simple device used in industry between tube wall and tube center because of the
for generation of cold and hot air streams from friction of the fluid circling at high speeds. Speed
a single compressed air supply. This simple of the fluid near the tube wall is lower than the
device is very efficient in separation of air speed at the tube center, because of the effects of
streams of different temperatures and has been wall friction. As a result, fluid in the center region
the focus of investigation since the tube’s transfers energy to the fluid at the tube wall,
discovery. Different explanations for the depending on the geometric structure of the vortex
phenomenon of the energy separation have been tube. The cooled fluid leaves the vortex tube from
proposed, however there has not been a the cold output side, by moving towards an
consensus in the hypothesis. The purpose of this opposite direction, compared to the main flow
paper is to present a critical review of current direction, after a stagnation point. Whereas, the
explanations on the working concept of a vortex heated fluid leaves the tube in the main flow
tube. direction from the other end (Dincer et al., in
Although many experimental and numerical press). By injecting compressed air at room
studies on the vortex tubes have been made, the temperature circumferentially into a tube at high
physical behaviour of the flow is not fully velocity, a vortex tube can produce cold air down to
understood due to its complexity and the lack of 223 K and hot air up to 400 K (Crocker et al.,
consistency in the experimental findings. 2003).
Furthermore, several different hypotheses based
on experimental, analytical, and numerical
studies have been put forward to describe the
thermal separation phenomenon. Hypotheses of
pressure, viscosity, turbulence & temperature
separation phenomenon using CFD analysis of
vortex tube are discussed in the paper, and
presumably, future research will benefit from
this discussion.[1]
.
Index Terms—RHVT, Thermal Separation, CFD

I. INTRODUCTION
Ranque discovered the effect of vortex
energy distribution and patented the first vortex
tube (RHVT) in 1934. In 1946, Hilsch improved
the RHVT design and its underlying principles that
still remain valid today (Khodorkov et al., 2003).
Aljuwayhel et al. (2005) define the vortex tube as a
simple device with no moving parts that is capable
of separating a high-pressure flow into two lower
pressure flows of different temperatures. The
device consists of a simple circular tube, one or
more tangential nozzles, and a throttle valve (see
Fig. 1, Cockerill, 1995).
Working principle of the counter flow RHVT can
be defined as follows. Compressible fluid, which is Fig. 1 – Schematic diagram of the counter flow
tangentially introduced into the vortex tube from RHVT (Cockerill, 1995).
nozzles, starts to make a circular movement inside
the vortex tube at high speeds, because of the Schematic diagram of the parallel flow
cylindrical structure of the tube, depending on its RHVT is shown in Fig. 2. Both hot and cold flows

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Rahul B Patela, Dr. V. N. Bartariab ,Tausif M Shaikhc / International Journal of Engineering
Vol. 2, Issue 4, July-August 2012, pp.
in RHVTs leave the vortex tube in the same on which physics can be applied for getting the
direction. It is not possible for cold flow to turn results. The CFD software gives one the power to
back after a stagnation point. In order to separate model things, mesh them, give proper boundary
the flow in the center of the tube from the flow at conditions and simulate them with real world
the wall, an apparatus which has a hole in the condition to obtain results. Using CFD a model can
center is used. The temperature of hot and cold be developed which can breed to give results such
flows can be changed by back and forth movement that the model could be developed into an object
of this apparatus. In parallel flow RHVTs, hot and which could be of some use in our life.
cold flows mix with each other. This mixing affects
the temperatures of fluids negatively and causes Modeling is the mathematical physics problem
their efficiencies to be low. For this reason, parallel formulation in terms of a continuous initial
flow RHVTs are generally not preferred (Dincer, boundary value problem (IBVP)
2005; Dincer et al., 2005) IBVP is in the form of Partial Differential
Equations (PDEs) with appropriate boundary
conditions and initial conditions.
Modeling includes:
1. Geometry and domain
2. Coordinates
3. Governing equations
4. Flow conditions
5. Initial and boundary conditions
6. Selection of models for different applications
Solve the Navier-Stokes equations (3D in Cartesian
coordinates) .
Fig. 2 – Schematic diagram of the parallel flow
RHVT (Dincer et al., 2005). Computational fluid dynamics techniques
have revolutionized engineering design in several
In the conventional vortex tube, important areas, notably in analysis of fluid flow
compressed gas enters directly a circular flow technology. CFD can also be used as a minimal
passage with equal section area from a straight adequate tool for design of engineering
pipe, which can cause a sudden change of flow components. A careful scanning of various
direction at the joint between the straight pipe and numerical investigations on the mechanism of
the circular flow passage. The sudden change thermal separation in vortex tubes indicate that
would lead to the generation of eddies, which cause barring a few ,no serious attempts have been made
energy loss. The sudden change of flow velocity to use CFD techniques to simulate the flow patterns
and the eddy generated by this change can also of vortex tubes.
cause the energy loss. It is important to have a high
peripheral velocity in the portion of the tube A detailed analysis of various parameters
immediately after the nozzle; the curve of the of the vortex tube has been carried out through
nozzle affects the performance of vortex tubes (Wu CFD techniques to simulate the phenomenon of
et al., 2007). flow pattern, thermal separation, pressure gradient
RHVTs are used, among others, for cooling, etc. so that they are comparable with the
heating, drying and snow production. Their cooling experimental results.
capability is used, e.g., in dehumidifying gas
samples, chilling of environmental chambers, The vortex tube was first observed by
cooling of food, welding, and air climate control Ranque. Later, Hilsch did some experimental and
processes. Although, they are not very efficient as a theoretical studies to increase the efficiency of the
cooling device, they can be very useful in certain vortex tube. Fulton explained the energy separation.
applications as they are small, simple to make and He proposed that the inner layer heat the outer layer
repair, and require no electrical or chemical power meanwhile expanding and growing cold. Reynolds
source. Nowadays, RHVTs are produced by did the numerical analysis of vortex tube. Lewellen
different commercial companies with a wide range arrived at the solution by combining the three
of applications (Dincer et al., 2008). [2] Navier-stokes equations for an incompressible fluid
in a strong rotating axisymmetric flow with a radial
II. INTRODUCTION TO CFD sink flow. Linderstorm-lang examined the velocity
MODELLING and thermal fields in the tube. He calculated the
CFD is concerned with numerical solution axial and radial gradients of the tangential velocity
of differential equations governing transport of profile from prescribed secondary flow functions
mass, momentum and energy in moving fluid. on the basis of a zero-order approximation to the
Using CFD, one can build a computational model

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momentum equations developed by Lewellen for an parameters for obtaining the maximum hot gas
incompressible flow. temperature and minimum cold gas temperature are
obtained through CFD analysis and validated
Schlenz investigated numerically in a uni- through experiments. The coefficient of
flow vortex tube, the flow field and the process of performance (COP) of the vortex tube as a heat
energy separation. Calculations were carried out engine and as a refrigerator has been calculated.
assuming a 2D axisymmetric compressible flow
and using the Galerkin's approach with a zero- Ahmet Murat Pinar et al, [6] were carried
equation turbulence model to solve the mass, out Optimization of counter flow Ranque–Hilsch
momentum, and energy conservation equations to vortex tube performance using Taguchi method.
calculate the flow and thermal fields. Amitani used This study discusses the application of Taguchi
the mass, momentum and energy conservation method in assessing maximum temperature
equation in a 2D model of a counter flow vortex gradient for the Ranque–Hilsch counter flow vortex
tube with a short length, with an assumption of a tube performance. The experiments were planned
helical motion in an axial direction for an invicid based on Taguchi’s L27 orthogonal array with each
compressible perfect fluid. Flohlingsdorf and Unger trial performed under different conditions of inlet
used the CFX system with the k-ϵ model to study pressure, nozzle number and fluid type. Signal-to-
the velocity profile and energy separation in a noise ratio (S/N) analysis, analysis of variance
vortex tube. Aljuwahel reported that RNG k-ϵ is (ANOVA) and regression analysis were carried out
better than k-ϵ when he studied the energy in order to determine the effects of process
separation and the flow phenomenon in a counter parameters and optimal factor settings. Finally,
flow vortex tube using CFD in Fluent. T. Farouk confirmation tests verified that Taguchi method
and B. Farouk introduced the large eddy simulation achieved optimization of counter flow Ranque–
(LES) technique to predict the flow fields and the Hilsch vortex tube performance with sufficient
associated temperature separation within a counter- accuracy.
flow vortex tube for several cold mass fractions.
However, most of the computations found in the Tanvir Farouk et al, [7] carried out
literature used simple or the first-order turbulence Simulation of gas species and temperature
models which are considered unsuitable for separation in the counter-flow Ranque–Hilsch
complex, compressible vortex tube flows. The vortex tube using the large eddy simulation
present work presents a two-dimensional numerical technique.A computational fluid dynamic model is
investigation of flow and temperature separation used to predict the species and temperature
behaviours inside a flow vortex tube.[3] separation within a counter flow Ranque–Hilsch
vortex tube. The large eddy simulation (LES)
III. EXPRIMENTAL & NUMRICAL technique was employed for predicting the gas flow
ANALYSIS and temperature fields and the species mass
From 1934, almost 200-215 articles are fractions (nitrogen and helium) in the vortex tube.
published on Ranque Hilsch vortex tube. Not all the A vortex tube with a circumferential inlet stream of
articles are directly related to our work, especially, nitrogen–helium mixture and an axial (cold) outlet
those articles which were focused on computational stream and a circumferential (hot) outlet stream
work. Many articles addressed experimental was considered. The temporal evolutions of the
findings and remaining discussed various theories axial, radial and azimuthal components of the
explaining energy separation phenomenon. In this velocity along with the temperature, pressure and
subsection, we are going to discuss only those mass density and species concentration fields
articles (experimental and/or theoretical work) within the vortex tube are simulated. Even though a
which are directly related to current work.[4] large temperature separation was observed, only a
very minimal gas separation occurred due to
Upendra Behera et al, [5] were carried out diffusion effects. Correlations between the
CFD analysis and experimental investigations fluctuating components of velocity, temperature
towards optimizing the parameters of Ranque– and species mass fraction were calculated to
Hilsch vortex tube. Computational fluid dynamics understand the separation mechanism. The inner
(CFD) and experimental studies are conducted core flow was found to have large values of eddy
towards the optimization of the Ranque–Hilsch heat flux and Reynolds’s stresses. Simulations were
vortex tubes. Different types of nozzle profiles and carried out for varying amounts of cold outlet mass
number of nozzles are evaluated by CFD analysis. flow rates. Performance curves (temperature
The swirl velocity, axial velocity and radial separation/gas separation versus cold outlet mass
velocity components as well as the flow patterns fraction) were obtained for a specific vortex tube
including secondary circulation flow have been with a given inlet mass flow rate.
evaluated. The optimum cold end diameter (dc) and
the length to diameter (L/D) ratios and optimum

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Rahul B Patela, Dr. V. N. Bartariab ,Tausif M Shaikhc / International Journal of Engineering
Vol. 2, Issue 4, July-August 2012, pp.

Fig. 1. Time averaged total temperature
contours for the vortex tube in the r–x plane
(case 1). Time averaging was performed between
0.4 and 0.8 s

Fig. 1. Schematic diagram of a counter-flow
Ranque–Hilsch vortex tube.

K. Dincer et al, [9] were carried out Experimental
Fig. 2. Time averaged helium mass fraction investigation of performance of hot cascade type
contours for the vortex tube in the r–x plane Ranque-Hilsch vortex tube and exergy analysis. In
(case 1). Time averaging was performed between this study, three Ranque-Hilsch vortex tubes were
0.4 and 0.8 s. used, which have 9 mm inside diameter and
length/diameter ratio was 15. Their performances
S. Eiamsa-ard [8] was carried out were examined as one of the classical RHVT and
Experimental investigation of energy separation in other was hot cascade type RHVT. Performance
a counter-flow Ranque–Hilsch vortex tube with analysis was according to temperature difference
multiple inlet snail entries. The energy/ between the hot outlet and the inlet (ΔThot). The
Temperature separation phenomenon and cooling ΔThot values of hot cascade type Ranque-Hilsch
efficiency characteristics in a counter-flow vortex tubes were greater than the ΔThot values of
Ranque–Hilsch vortex tube (RHVT) are classical RHVT, which were determined
experimentally studied. The ascertainment focuses experimentally. The total inlet exergy, total outlet
on the effects of the multiple inlet snail entries exergy, total lost exergy and exergy efficiency of
(N=1 to 4 nozzles), cold orifice diameter ratios hot stream were investigated by using experimental
(d/D=0.3 to 0.7) and inlet pressures (Pi=2.0 and 3.0 data. In both the classical RHVT and hot cascade
bar). The experiments using the conventional type RHVT, it was found that as fraction of cold
tangential nozzles (N=4), are also performed for flow increases the total lost exergy decreases. It
comparison. The experimental results reveal that was also found that, the hot cascade type RHVT
the RHVT with the snail entry provides greater cold more exergy efficiency of hot outlet than the
air temperature reduction and cooling efficiency classical RHVT. Excess ΔThot value of hot cascade
than those offered by the RHVT with the type Ranque-Hilsch vortex tube causes the excess
conventional tangential inlet nozzle under the same exergy efficiency of hot outlet.
cold mass fraction and supply inlet pressure. The
increase in the nozzle number and the supply H.M. Skye et al, [10] were carried out
pressure leads to the rise of the swirl/vortex Comparison of CFD analysis to empirical data in a
intensity and thus the energy separation in the tube. Commercial vortex tube. This paper presents a
comparison between the performance predicted by
a computational fluid dynamic (CFD) model and

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experimental measurements taken using a [2] K. Dincer et al, were carried out
commercially available vortex tube. Specifically, ―Experimental investigation of the
the measured exit temperatures into and out of the performance of a Ranque–Hilsch Vortex
vortex tube are compared with the CFD model. The tube with regard to a plug located at the
data and the model are both verified using global hot outlet‖.
mass and energy balances. The CFD model is a [3] Prof. R. K. Sahoo et al, were carried out
two-dimensional (2D) steady axisymmetric model ―Numerical Analysis in Ranque-Hilsch
(with swirl) that utilizes both the standard and Vortex tube.‖
renormalization group (RNG) k-epsilon turbulence [4] Sachin U. Nimbalkar et al, were carried
models. While CFD has been used previously to out ―Quantitative observations on multiple
understand the fluid behavior internal to the vortex flow structures inside Ranque Hilsch
tube, it has not been applied as a predictive model vortex tube.‖
of the vortex tube in order to develop a design tool [5] Upendra Behera et al, were carried out
that can be used with confidence over a range of ―CFD analysis and experimental
operating conditions and geometries. The objective investigations towards optimizing the
of this paper is the demonstration of the successful parameters of Ranque–Hilsch vortex
use of CFD in this regard, thereby providing a tube.‖
powerful tool that can be used to optimize vortex [6] Ahmet Murat Pinar et al, were carried out
tube design as well as assess its utility in the ―Optimization of counter flow Ranque–
context of new applications. Hilsch vortex tube performance using
Taguchi method.‖
[7] Tanvir Farouk et al, were carried out
―Simulation of gas species and
temperature separation in the counter-flow
Ranque–Hilsch vortex tube using the large
eddy simulation technique.‖
[8]. S.Eiamsa-ard was carried out
―Experimental investigation of energy
separation in a Counter- flow Ranque–
Hilsch vortex tube with multiple inlet snail
entries.‖
Fig. 3. Picture of vortex tube used for [9] .K. Dincer et al, were carried out
experiment. ―Experimental investigation of
performance of hot cascade type Ranque-
IV. CONCLUSION:- Hilsch vortex tube and exergy analysis.‖
The issue concerned in all explanations is [10]. H.M. Skye et al, were carried out
the energy transfer between different layers. When Comparison of CFD analysis to empirical
little energy is transferred from the inner flow to data in a Commercial vortex tube.
the outer flow, the temperature drop of cold air can
be considered to be the result of sudden expansion
near the entrance, and the temperature rise of hot
air might be the result of friction of the multi-
circulation near the hot exit. Therefore, clarification
of the energy transfer between different layers is a
useful approach in the investigation of the vortex
tube. Clear understanding of the flow structure
inside the vortex tube is required for further
investigation, especially the region near the
entrance in which sudden expansion is considered
as the governing process and the region near the
exit in which multi-circulation may be formed.

From the above study I am much more interested to
work on Experimental & Numerical investigation
of Ranque-Hilsch vortex tube using CFD.

V. REFERENCES
[1] Yunpeng Xue et al, were carried out ―A
critical review of temperature separation
in a vortex tube‖.

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