Check one of the first systematic literature review on vortex tube in which a meticulous comparison of experimental and simulation work is done. D Alembert's paradox and paradox in general is witnessed and which ends with description from most appropriate author felt by the author (Behara et al).

1. COMPUTATIONAL FLUID DYNAMICS SIMULATION
ON VORTEX TUBE:
A REVIEW
Presentation by
Kush Verma
Roll No 3203052
Under the Guidance of
Dr. P M Meena
Professor
Department of Mechanical Engineering
Faculty of Engineering, J N V University
Jodhpur - 34200 1 Rajasthan INDIA

2. OUTLINE OF PRESENTATION
28 January 2018 Presented by Kush Verma 2
• Introduction
 Background and present status
 Need for work on Ranque Hilsch Vortex Tube
 Gaps in existing technology and bridging these gaps
 Aims and objective
• System selection
 System selection and parameters
 Air compressor
 Ranque Hilsch Vortex Tube
 Computational Fluid Dynamics system
• Literature review
 Types of vortex tube
 Experimental modeling styles
 Simulated modeling styles
 Effects of vortex tube parameters
 Fluid dynamics of Ranque Hilsch Vortex Tube
• Conclusions and future work

3. INTRODUCTION
Background and present status
28 January 2018 Presented by Kush Verma 3
• RHVT is a mechanical device which separates
pressurised stream into cold and hot streams.
• Its applications are:
 Cooling and air conditioning
 Manned underwater suits
 Hyperbaric chambers and suits
 Cooling of cutting tools
 Cooling of suits for mining and shot
Blasting workers
 Alternative to throttling device
 Phase changing
 Liquefaction of natural gas
 Separation.
 Chip removal
 Particle and gas separator

4. BACKGROUND AND PRESENT STATUS Cont..
28 January 2018 Presented by Kush Verma 4
• The design of a vortex tube depends on its
geometrical dimensions such as
 Length of tube (L)
 Diameter of tube (D)
 Diameter of orifice (dϕ) or cold tube
diameter (dc)
 Nozzle number (N), diameter (dn), area
(Ai), shape and location of nozzles
 Cold exit area (Ac)
 Hot exit area (Ah) or hot side valve
opening angle
 Angle of taper of tube (0<𝛼<4, in case of
conical tube).

5. BACKGROUND AND PRESENT STATUS Cont..
28 January 2018 Presented by Kush Verma 5
• Various performance parameters (with typical range of values)
are listed as
 Cold mass fraction, μc =
mc
mi
, where 0 < μc < 1
 Temperature drop, ∆Tc= (Ti − Tc), where 0 < ∆Tc < 230K (Comassar, 1951)
 Cooling performance, Qc = μcCp(Ti − Tc), where 0 < Qc < 1000kJ𝑘𝑔−1
 Coefficient Of Performance, COP =
Qc
Wc
=
μcCp(Ti−Tc)
Wc
,where 0<COP<0.5
 Isentropic efficiency, ηc = μc
(Ti−Tc)
Ti(1−(
pi
pa
)
λ−1
λ )
, where 0 < ηc < 0.42 (Camire,
1995)

6. NEED FOR WORK ON R.H.V.T
28 January 2018 Presented by Kush Verma 6
• The basic need comprises of:
 To understand the Ranque
Hilsch effect
 Optimize the performance
parameters
 harnessing waste pressure
sources listed in table 1.
 Need for work in the field of
Technical Inclusion.
Table 1: Nimbalkar (2009) listed various waste
industrial pressure sources which can be
harnessed using RHVT.

7. GAPS IN EXISTING TECHNOLOGY AND
BRIDGING THESE GAPS
28 January 2018 Presented by Kush Verma 7
• Some of the gaps are:
 Bottlenecks in the form of computer
performance speed (FLOPS)
 Complex problems such as
 Inverse problem
 Parametric research
 Multidisciplinary problems
have not been addressed so far
• The factors which influence these problems are
 Parallel computing
 Digital revolution
 Growth and confluence of mathematical
methods

8. GAPS IN EXISTING TECHNOLOGY AND
BRIDGING THESE GAPS Cont…
28 January 2018 Presented by Kush Verma 8
• The solutions suggested by Bondarev and Galaktionov (2014) includes work in:
 Flow visualization
 Dimensional reduction through dimensional constants monitoring
 Visualization for each grid point
 Flow discontinuity detection
 Building an integrated platform using hyperFun (open-source) language
• Walking a step forward to their suggestions, it is proposed to use
 Dimensional analysis for all Mesh created at all patches
 Sensitivity analysis for control over the process

9. AIMS AND OBJECTIVE
28 January 2018 Presented by Kush Verma 9
• The objectives of this seminar work is to carry out literature survey and:
 To obtain optimum values of performance and design parameters
 To obtain the effects of R.H.V.T parameters such as L, L/D, 𝑑∅/D
ratios, N, μ 𝑐
, hot opening area, Aℎ and angle
 To understand Ranque Hilsch effect
 To define hypothesis regarding the working of vortex tube
 To observe transition in theory and practice known as D-Alembert's
paradox
 To suggest modifications for improving the performance of the vortex
tube
 To discover vitality of time factor
 To do self-appraisal by finding self-capabilities

10. SYSTEM SELECTION AND PARAMETERS
28 January 2018 Presented by Kush Verma 10
• Schematic of system with its sub
systems and parameters:
1. Air Compressor
2. R.H.V.T
3. Computer with C.F.D system.

11. SYSTEM SELECTION AND PARAMETERS Cont…
Air compressor
28 January 2018 Presented by Kush Verma 11
• Air compressor is a device that converts electric power to potential energy by
pressurizing fluid in a storage tank.
• It provides compressed air to R.H.V.T at an inlet pressure (𝑝𝑖) and mass flow rate as
C.F.M (Cubic Feet per Minute)
• In CFD system a compressor can be by-passed by setting correct boundary
conditions (𝑝𝑖, 𝑚𝑖).
• The expression for work done required for finding the COP of the system is as
shown.
Wc = mi × R(
Ti−T0
1−n
)

12. SYSTEM SELECTION AND PARAMETERS Cont…
RHVT design
28 January 2018 Presented by Kush Verma 12
• The thumb rule for design suggested in blogs of Otto Balden is selected:
 Internal diameter of tube: D
 Length of hot end tube (L): = 45×D
 Length of cold end tube: 10×D
 Diameter of orifice(𝑑ϕ) or cold tube diameter (𝑑c):= D/2
 Number of nozzles (N): = 2 to 6.
 Inlet air nozzle diameter (𝑑n): = 4mm to 5mm.
 Length of vortex generation chamber: = 2×D to 3×D
 Internal diameter of vortex generation chamber: =2×D
 Diameter of nozzle of vortex chamber:=D/(6 to 7)
 Area (Ai), shape and location of nozzles
 cold exit area (Ac)
 hot exit area (Ah) or hot side valve opening angle
 angle of taper of tube (0<α<4, in case of conical tube)

13. SYSTEM SELECTION AND PARAMETERS Cont..
CFD system
28 January 2018 Presented by Kush Verma 13
• Computational Fluid Dynamics is a branch of Computational Mechanics
which uses Volume of Fluid (V.O.F) approach which requires:
 Satisfying Knudsen criteria (Kn<= 0.001) to ensures that control
volume is not affected by intermolecular forces
Kn =
Ma
Re
γπ
2
 To solve transport equations for given domain (like RHVT) to find
values of state variables (p, U, T) and their field distributions at
intrinsic or extrinsic sites
 Specifying initial and boundary conditions along with thermal and
physical properties as required
 Range of choices for controlling the process, solvers and interpolation
schemes.

14. SYSTEM SELECTION AND
PARAMETERS Cont…
CFD sub systems
28 January 2018 Presented by Kush Verma 14
• C.F.D system has some sub systems mentioned as pre-processing, discretization,
equation decoupling, boundary conditions, fluid models and post processing.
 Preprocessing or meshing discretizes (divided) a domain into meaningful
divisions(elements)
 Discretization:
 Is approximation of a problem into discrete quantities
 Methods include FEM, FVM, FDM
 Types include
 Spatial discretization defines the solution domain by a set of points
 Temporal discretization dividing the time domain into number of
time intervals
 Equation discretization generates a system of algebraic equations
from the P.D.Es that characterize the problem

15. SYSTEM SELECTION AND PARAMETERS Cont…
CFD sub systems
28 January 2018 Presented by Kush Verma 15
• Equation decoupling
 Transport equations (Navier-Stokes) are nonlinear in convection term and
coupled through pressure and velocity so decoupling methods are required.
 Some standard decoupling loops are SIMPLE, PISO and PIMPLE
• Boundary and input conditions
 Exterior sites involve specifying boundary conditions
 R.H.V.T generally has three sites namely input nozzle, cold outlet and hot
outlet.
• A CFD system has some parameters like number of cells, orthogonality and
skewness which limits the created geometry.
• Fluid models are used to invoke specific flow or thermal conditions
• Post processing is used to process the results obtained.

16. LITERATURE REVIEW
Experimental Modelling styles
28 January 2018 Presented by Kush Verma 16
• RHVT is of two types parallel flow vortex tube and
counter flow vortex tube
 These can be of cylindrical or conical type
 These are modelled as:
 Adiabatic compression and expansion
model: Ranque (1933).
 Sudo adiabatic expansion with wall
friction model: Hilsch (1946)
 Free vortex flow with turbulence effect
model: Fulton (1950)
 Acoustic streaming model: Kuroska
(1985)
 Secondary circulation model: Ahlborn
(1994)
 Paddle wheel model: Camire (1995)
 Forced vortex model with turbulence and
axial convection model: Nimbalkar (2009)

17. LITERATURE REVIEW Cont…
Simulated modeling styles
28 January 2018 Presented by Kush Verma 17
• Standard commercial models:
 2D axis-symmetric:
 skye et al., (2006)
 Giorgio de vera (2010)
 Azizi et al., (2014),
 Rahbar et al., (2015)
 3D models:
 Vlad and Hank (2004)
 Hossein nezad and Shamsodini (2009)
 Zin et al (2010)
 Pourmahmoud and Bramo (2011)
 Pouraria and Park (2014)
 Khait et al.,(2013)
 Pourmahmoud et al.,(2011)
 Azizi et al., (2014)
 Rahbar et al., (2015)
• Investigations on uni-flow commercial 3D model: Noor et
al., (2012)

18. LITERATURE SURVEY Cont…
Effects of R.H.V.T parameters
• Length and diameter of vortex tube
(L, D, L/D)
 Vortex tube with smaller diameter
Pourmahmoud and Brahmo
(2014) (micro scale vortex tubes)
 L/D ratio of 10
 Large diameter tubes Kargaran et
al., (2013)
 L/D ratio of 42.31 (i.e <=45)
 No effect of length on tube
performance between
 45 × d to 55 × d
• Inlet area and nozzle number and
diameter (Ai, N, dn).
 Increasing the number of nozzles
for same area of inlet increases
the temperature separation
(Eaimsaard and Promvonge,
2008 )
 Kshirsagar et al., (2014) showed
that nozzles between 4 and 6,
gave higher temperature drop.
 Increasing size of nozzle
diameter
 η ΔT
28 January 2018 Presented by Kush Verma 18

19. LITERATURE SURVEY Cont…
Effects of R.H.V.T parameters
• Cold mass fraction (𝛍 𝐜):
 Coefficient of performance is
independent of the L for (Rahabar
et al., (2015))
 𝝁 𝒄 <0.35
 Orifice diameter is insignificant for
(Kshirsagar et al., (2014))
 𝝁 𝒄 <0.65
 Least entropy is generated at
(Kargaran et al., (2013))
 𝝁 𝒄 =0.65
• Cold mass fraction (𝝁 𝒄):
 Lower for better temperature drop
 Higher for better cooling effect
• Diameter of orifice( dϕ or dc).
 Increasing the size of 𝒅 𝝓 leads
to the transition from
 ΔT η
 Larger orifice to tube diameter
ratio (0.6 to 0.9) causes less
temperature separation while
smaller ratio (0.2 to 0.4) causes
larger back pressure (Eaimsaard
and Promvonge, 2008)
• Hot opening area (Ah) should be
less than 20% of tube area Singh
et al., (2004).
28 January 2018 Presented by Kush Verma 19

20. LITERATURE REVIEW Cont…
Xue et al., (2010)
Fluid dynamics of RHVT
28 January 2018 Presented by Kush Verma 20
• Adiabatic expansion and compression (Ranque, 1933) theory:
 Rejected by Xue et al., (2010) as calculation from p1
γ−1
T1
−γ
= p2
γ−1
T2
−γ
, T1v1
γ−1
=
T2v2
γ−1
gave temperatures way high -57oC or -67oC as against actual -1oC
• Non adiabatic expansion with wall friction model: Hilsch (1947),
 tested by Xue et al., (2010) gave a temperature rise of 1.8K only
• Free vortex flow models with turbulence (Kassner and Knoernschild, 1948, Fulton, 1950)
• Forced vortex model with turbulence and axial convection: Nimbalkar (2009)
• Secondary circulation model: Ahlborn (1994), improved by Nimbalkar (2009)
 Limited to vortex tube of orifice to tube diameter ratio :
𝒅∅
𝑫
< 0.58

21. LITERATURE REVIEW Cont…
Xue et al., (2010)
Fluid dynamics of RHVT
28 January 2018 Presented by Kush Verma 21
• Acoustic streaming model (Kuroska, 1985):
 Increase of inlet pressure, sudden rise of the temperature occurred with
drop in sound pressure level (dB).
 Evidence were not conclusive in selected cylinder flow
• Turbulences models (standard k–ε model, LES, ASM, RSM)
 Suitable for specific occasions.
 Different turbulence parameters and assumptions result in different,
contradictory conclusions without any general trend.

22. CONCLUSIONS AND FUTURE WORK
Performance based
28 January 2018 Presented by Kush Verma 22
• Performance parameters like higher temperature drop, cooling effect and
isentropic efficiency cannot be obtained simultaneously as per Singh, et al.
(2004).
• Hot valve opening and temperature drop
 Hot end valve almost closed (Yadav et al., 2016)
 Valve opening angle is 50o (Eaimsaard and Promvonge, 2008)
 Ratio of hot outlet area and tube area of 0.2 Singh et al., (2004).
• Optimal isentropic efficiency occurs at an inlet pressure of 200kPa (Eaimsaard
and Promvonge, 2008).
• k-omega-SST turbulence model is robust and gives better resolutions of field
values.
• Thermal time scale value of 22 minutes and fluid dynamic scale value of 3
minutes (Nimbalkar , 2009).

23. CONCLUSIONS AND FUTURE WORK Cont…
Design based
28 January 2018 Presented by Kush Verma 23
• The design specifications noted fro the literature are:
 Length of the vortex tube (L)
 L > 45 × D
 Or 20 × D < L < 40 × D
 L>24×D. (Takahama, 1965)
 No effect on performance for 45 × D <L < 55 × D.
 Nozzle and temperature drop.
 N × 𝒅 𝑛
2/ D2 < 0.35 Nimbalkar (2009)
 N × 𝒅 𝑛
2/ D2 = 0.33 Eaimsaard and Promvonge ( 2008)
 0.16 < N × 𝒅 𝑛
2/ D2 <0.2. Takahama (1965)
 Pourmahmoud et al., (2012) recommended helical nozzle shape
 Orifice diameter (𝒅 𝝓)
 Optimal 𝒅 𝝓= 0.5 × D (Eaimsaard and Promvonge, 2008).
 𝒅 𝜙
2/ D2 = 0.080 ± 0.001 for achieving maximum ΔT (Singh et al.,2004)
 𝒅 𝜙
2/ D2 = 0.145 ± 0.035 for attaining the maximum η (Singh et al.,2004)
 0.4D < 𝒅 𝝓 <0.66D (Nimbalkar, 2009)
 𝒅 𝝓< D -2× 𝒅 𝑛. (Takahama, 1965)

𝒅∅
𝑫
= 𝟎. 𝟓𝟒𝟒, (Pouraria and Park, 2013)

24. CONCLUSIONS AND FUTURE WORK Cont…
Design based
28 January 2018 Presented by Kush Verma 24
• Design modifications of thumb rules of Otto Balden:
 To begin with the design start by selecting the diameter of vortex tube,
D
 Number of nozzles (N) (Kshirsagar et al., 2014) which should be
between 4 and 6, preferably 4.
 Diameter of orifice, 𝒅 𝜙 := 0.544×D
 Diameter of inlet nozzles, 𝒅 𝑛 := 0.12×D to 0.166×D
 Length of hot end tube, L:= 10×D (for D<=10mm) or 20×D (for
D<=25mm) or 42.31×D (for D>25mm)
 Rest being the same or proportional to the hot side tube length

25. CONCLUSIONS AND FUTURE WORK Cont...
Chakraborty D. (2010)
28 January 2018 Presented by Kush Verma 25
 Range of CFD activities in India at:
 Bangalore: Aerospace related activities at IISc, NAL, HAL, ADE, ADA,
GTRE.
 Trivandrum: Launch vehicle related activities at Vikram Sarabhai Space
Centre (VSSC).
 Hyderabad: Missile related CFD activities at Defense Research and
Development Laboratory (DRDL)
 NAL developed in house codes (JEWEL3D, JUMBO3D) for HANSA and
SARAS projects.
 Tejas (multirole LCA) developed both for air-force and navy by ADA from
interactions with HAL, IISc, and IITs used CFD extensively
 Around 500 researchers were working in the field of CFD by 2010
(Chakraborty D., 2010).

26. CONCLUSIONS AND FUTURE WORK Cont...
Chakraborty D. (2010)
28 January 2018 Presented by Kush Verma 26
• SARAS project is promised to be
revived in 2017
• It was abandoned earlier to design
related issues.
• To conclude think parallel and do
parallel in the motive of Indian
C.F.D program.

27. CONCLUSIONS AND FUTURE WORK Cont…
Future work
28 January 2018 Presented by Kush Verma 27
• Working in the field for technical inclusion.
• The future course can be in form of attempts to:
 Make a hypothesis in form of guess statements,
 Suggest suitable design modifications in the design of RHVT
 Formulate and test an hypothetical equation using dimensional analysis under
some future C.F.D simulation with manipulation and code alterations for closer
predictions for the performance of the R.H.V.T.
• Finally the thesis writing and defense presentation are proposed in next phase in
direction of completion of master’s degree in engineering.

28. THANK YOU.
Presented by Kush Verma
M.E thermal engineering, II year
MBM engineering college.
28 January 2018 Presented by Kush Verma 28

29. SYSTEM SELECTION AND DESIGN
PARAMETERS Cont…
RHVT performance
28 January 2018 Presented by Kush Verma 29
• Performance parameters
 Cold mass fraction for R.H.V.T is given by the equation shown below
μc =
mc
mi
 Cooling performance of R.H.V.T can be evaluated as per equation shown
below
Qc = μcCp(Ti − Tc)
 C.O.P or coefficient of performance which is the ratio of cooling effect to the
compressor work input can be evaluated as per equation shown below
COP =
Qc
Wc
=
μcCp(Ti−Tc)
Wc
 Energy separation efficiency as per first law is given by equation shown below
ηc = μc
(Ti−Tc)
Ti(1−(
pi
pa
)
λ−1
λ )

30. LITERATURE REVIEW Cont…
Singh et al.,(2004)
Size effect
28 January 2018 Presented by Kush Verma 30
• Singh et al., (2004) classified nozzle and
orifice design into four combinations,
required for achieving greater temperature
drop or greater efficiency.
• And recommended
 smaller hot side opening area
(<=0.2( π
4
D2) and smaller orifice
(0.08D) for achieving more
temperature drop and
 Bigger orifice for more efficiency
(0.145D)
 Tube length between 45D to 55D.

31. LITERATURE REVIEW Cont..
Bondarev and Galaktionov (2014)
28 January 2018 Presented by Kush Verma 31
• Bondarev and Galaktionov (2014)
classified CFD problems as
 Direct problem (cause is known and
effect is required to be known).
 Inverse problem (only effect is
known but cause is unknown)
 Multidiscipline problem
 Optimized parametric research.
 Recommended multidimensional
data analysis and
 parametric optimization
 Also high end parallel computing for
all kinds of complex problems.

32. LITERATURE REVIEW Cont…
Pourmahmoud et al., (2011)
Size effect
28 January 2018 Presented by Kush Verma 32
 Pourmahmoud et al., (2011) took sets of equal area 6 straight, 3 straight and 3 helical
nozzles and
 hypothesized the helical nozzles gave better performance at some cost of pressure drop.
 Pourmahmoud et al., (2012) investigated the effects of inlet pressure.
 Later they investigated effect on performance of RHVT with lateral squre hole at the
entry of the nozzle.

33. LITERATURE REVIEW Cont…
Rahbar et al., (2011)
Size effect
28 January 2018 Presented by Kush Verma 33
• Rahbar et al.,(2015) performed numerical
simulation on a micro-scale vortex tube
• Using SST (Shear Stress Transport) k-omega
turbulence model
• Concluded that the mass flow fractions (0.58 and
0.65) for maximum temperature drop and
maximum cooling effect (refrigerating power) were
near the peaks.
• Yadav et al., (2016) performed parametric size
effect testing on R.H.V.T and
• Gave various conclusions for the length L, length
to tube diameter L/D, orifice to tube diameter d/D
and number of nozzles.