Check out one of the first of its kind simulation work on Ranque Hilsch Vortex Tube. The authors have done exhaustive work including simulation (from multiple application software Ansys and OpenFOAM), programming (C++ and excel) and plots (excel and qtiplot) along with experimental work. They have simplified and standardized the process to an extend that it would even be helpful for a beginner in this field.

1. COMPUTATIONAL FLUID DYNAMIC SIMULATION
AND BENCHMARKING FOR RANQUE HILSCH
VORTEX TUBE
Presentation by
Kush Verma
Roll No 3203055
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
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• Introduction
 Background
 Present status and need for work on R.H.V.T
 Aims and objective
 Methodology
• System selection
 Physical modelling
 Designing Fabrication and Testing R.H.V.T
 Computational modelling
 Pre-Processing, case setup and solving
 Numerical setup plan
• Results and discussion
 Contours, plots and benchmarking
 Discussion
 Effects on R.H.V.T performance parameters
• Conclusions and future work
 Work done
 Parameteric classification
 Working of R.H.V.T

3. INTRODUCTION
Background
28 January 2018 Presented by Kush Verma 3
• Simulation
 Digital prototyping real world scenario for improving design
• C.F.D
 Science of predicting behaviour of fluid flow, mass transfer, chemical
reactions, for applications and analyzing such as
 Flows, turbulence, pressure distribution for fluids and their interaction
with structures.

4. INTRODUCTION Cont..
Present status of C.F.D and need for work on R.H.V.T
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• Present status of C.F.D:
 The Global C.F.D market research report 2014-18 by Technavio projected
the growth of 12.85% C.A.G.R.
 Dedicated work is planned for Kaveri, 1st indigenous gas turbine engine.
 SARAS project is expected to be revised in 2017.
 Tejas MK2 is in improvement stage.
• Need for work on R.H.V.T:
 There is a need to generalize the process of simulation.
 Since the discover of R.H.V.T in 1933 no theory accepted by critiques
 The C.F.D theory proposed by Behera at al.,(2008) needs critically
examination.

5. INTRODUCTION Cont..
Aims and objective
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• Purpose of this work :
 To critically examine the work of Behera et al.,(2008)
 To propose alternative theory for working of R.H.V.T and its cooling
effect.
 To do parametric study on R.H.V.T
 To understand Ranque Hilsch effect by numerical and C.F.D simulation
 Self-appraisal.

6. INTRODUCTION Cont..
Methodology
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• Approach, methodology and tools involves:
 Abstraction, quantization and quality improvement.
 Electrical analogy: Tracking overall process using electrical modelling and
quantization.
 Dimensional analysis: Monitoring dimensional constants at boundary patches
and inside the domain.
 Benchmarking: simulated results are compared, corrected, improved, made
reliable and various initial conditions are tested
 using circular referencing and numerical finite differencing methods in
spreadsheet supplemented by spreadsheet.

7. SYSTEM SELECTION
Physical modeling
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• System selection includes physical and computational modelling and
numerical setup plan consisting of
 Air compressor
 R.H.V.T (design and fabrication suggested by Meena and Verma
(2017))
 For tube I.D: d,
 Diameter of orifice: 48.4% to 54.4% of d,
 Diameter of inlet nozzles: 20%×d to 28.7% of d
 Length of hot end tube:10×d (for d≤15mm) or 20×d (for
d≤25mm), or 30×d (for d>25mm).
 Length of cold end tube: 2×d (for d≤15mm) or 4×d (for
d≤25mm), or 9×d (for d>25mm).
 Number of Nozzles: 4 (for d≤15mm) or 6 (for d≤25mm), or
8 (for d>25mm).
 Length of vortex generating chamber: 2×d
 Internal diameter of vortex generating chamber: 2×d.

8. SYSTEM SELECTION Cont..
Physical modeling
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• R.H.V.T fabrication
 Cold and hot side PVC tube are taken.
 Vortex chamber from pipe coupling made by foiling inside grooves and fixing nozzle by
threading.
 Orifice connected between the pipes and assembled with vortex chamber using reducing
couplings, Teflon tape and glue to make it air tight.
 Cup cone valve is connected at the hot end.
 R.H.V.T connected to compressor for taking reading.
• R.H.V.T testing with
 Compressed air as working fluid at pressure of 166825Pa.
 To give Th =304.177K, Tc=295.16K and Ti=297.26K(digital temperature indicator).
 At atmospheric conditions of 101325Pa , 302.05K and density 1.1685kgm-3.

9. SYSTEM SELECTION Cont..
Computational Modeling
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• C.F.D system has sub systems, pre-processing,
equation decoupling, case set-up, case solving and
post processing.
 Pre-Processing includes
 Discretization (dividing)
 For geometry (Spatial discretization)
 For time (Temporal discretization)
 For governing equations (Equation
discretization)
 Mesh quality check for number of cells,
orthogonality and skewness

10. SYSTEM SELECTION Cont..
Computational Modeling
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• Equation decoupling
 Required because of nonlinearity in convection (U^2) term and pressure-velocity (p-U)
system of equations. Methods include SIMPLE, PISO and PIMPLE.
• Case setup
 Includes selecting fluid, thermal models, solvers, convergence criteria and initializing
 Boundary and initial conditions
 Exterior or interior sites require specifying boundary and initial conditions
• Solving the case
 The matrix assembly is run for iteration and solution is monitored for residues, errors,
un-bounds, crash etc.
• Post processing is used to process the results obtained.

11. SYSTEM SELECTION Cont..
Numerical Setup Plan
• Creation of (6-7) independent variables n,
D, μc, G, I, L and C.
 Linear input state variable (n)
 Created from two known points
S.T.P (p=1bar, T=273.15K,
ρ=1.2756kgm-3) and test point
(p=1.66825bar, T=297.26K,
ρ=1.018 kgm-3) for varying p, Ti,
Th, Tc, hi, hh, λ,α Cp, and Cv.
 Compressor diameter (D) gives
volume, mass flow rates and inlet
velocity
 Cold mass fraction (μc) gives cold
and hot side pressure and velocities
 Geometry scaling factor (G) gives
 Turbulent intensity (I) giving
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12. SYSTEM SELECTION Cont..
Numerical Setup Plan
 Local components (L) and Swirl velocity
component (C)
 Gradient, divergence and Laplacian
calculation
 These independent variables governed
some dependent variables
 Isentropic efficiency (ηis)
 Coefficient of performance (COP)
 Temperature source scale (Th)
 Temperature difference scale (Th-
Tc)
 Entropy (s)
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13. RESULTS AND DISCUSSION
Contours and plots
• 2d contours
• 3d contours
• Post processed plot
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14. RESULTS AND DISCUSSION Cont..
Benchmarking and Discussions
• Benchmarking
 Involves comparing simulated
and numerical calculation from
spreadsheet.
 Tricky compromise between
C.F.D and numerical techniques
is desirable.
• Discussions
 Effect on temperature difference (Th-Tc)
 (n ) is necessary and sufficient
 (D) increases (Th-Tc) maximum at
the cost of COP, followed by, (G) ,
(n) and (I).
 G) geometry scaling factor
increases (Th-Tc) without loss in
COP
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15. RESULTS AND DISCUSSION Cont..
Benchmarking and Discussions
• Effects on COP.
 (n) is necessary and sufficient for COP
 Increasing (I) and (C) both increases COP
 (D) Compressor diameter decreases COP
 Increasing , (D) and (G) reduces COP.
• Effects on isentropic efficiency (ηis)
 (n) is necessary and sufficient for (ηis )
 (D) Decreasing order of (ηis) is obtained from
increasing order of (D)> (I) or (C) > (G).
 (G) Geometry scaling factor reduces (ηis)
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16. RESULTS AND DISCUSSION Cont..
Benchmarking and Discussions
• Effects on entropy (s)
 All 4 highest valued (s) curve
included (G), none included (C).
 3 out of 4 least (s) curves had
(C).
 (μc) decreases (s) invariably.
• Effect of length of hot side tube (L)
 Spatial variations of fluid
dynamic quantities
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17. CONCLUSION AND FUTURE WORK
Work done and R.H.V.T working
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• So far in this work
 literature review, experimental study, parametric study, numerical study,
simulation study is done
 Theory for working, design, parametric effects, temperature separation, cooling
effect is stated
• Working of R.H.V.T
 Compressive work (Wc) produces inlet energy.
 Temperature source T* due to turbulence
 Dominant lengthwise temperature difference
(Th-Tc) produced by greater forced
convection near hot end and throttling

18. CONCLUSION AND FUTURE WORK
Working and cooling Hypothesis
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• Working of RHVT
 Less dominant radial temperature difference
produced due to greater forced convection at
periphery (Tw-Tcr) due to diffusion resulting
 Net work (W-Q) causing higher shift
• Theory for cooling effect in R.H.V.T
 Time rate decrement of temperature at far field near cold end due to diffusion.
 Value of (-0.249Ks-1) obtained at steady state assumption from

19. CONCLUSION AND FUTURE WORK Cont..
Parameter classification
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• General conclusions
 R.H.V.T works on open system
 All performance parameters temperature separation (Th-Tc), isentropic efficiency
(ηis), and COP cannot be simultaneously increased.
• Vital, Essential and Desirable (VED) parameter classification
 Vital (V)
 (n) Linear input variable or state variable -> necessary and sufficient to
cause COP, temperature drop and isentropic efficiency
 Nozzle design-> Should cause fluid acceleration for turbulence work within
limited Mach number

20. CONCLUSION AND FUTURE WORK Cont..
Parameter classification
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 Essential (E)
 Compressor diameter (D) -> Optimum value is essential to increase the
temperature separation (Th-Tc)
 (C) and (I)
 Improves both isentropic efficiency (ηis) and COP.
 Tangential nozzle numbers-> More nozzle numbers essential as they increases
swirl flow.
 (G)
 Optimum value improves temperature separation (Th-Tc), increases entropy
(s) but reduces COP and isentropic efficiency (ηis)
 (L/d)
 Optimum ratio improves R.H.V.T performance and reduces entropy

21. CONCLUSION AND FUTURE WORK Cont..
Parameter classification
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 (Desirable (D)
 Cold mass fraction (μc)
Reduces entropy (s), optimizes temperature drop (Th-Tc) and
COP
 Orifice diameter
Larger size improves temperature separation (Th-Tc) but
reduces isentropic efficiency and vice-versa.
 Length of tube (L)
Optimum size reduces entropy

22. CONCLUSION AND FUTURE WORK Cont..
Future work
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• Future work shall be
 Working in the field of technical inclusion
 Solving Scalar transport equation with temperature source (Th)
 Suggest expression for heat transfer transfer coefficient (htc) better than
Colburn analogy as it gives value of htc of the order of 1e-10 to 1e-12 which
increases the value of temperature source T* and (Th-Tc).

23. PAPER PUBLICATIONS
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 Paper publication done on “ Computational Fluid Dynamics
Simulation on RHVT: A Review”. Meena and Verma (2017).
 Coming paper publication on “ Computational Fluid Dynamic
Simulation and Benchmarking for Ranque Hilsch Vortex Tube” Meena
and Verma (2017).

24. THANK YOU.
(Special thanks to my guide Dr. P.M Meena and H.O.D Dr. R. Bhagwat.)
Presented by Kush Verma
M.E thermal engineering, II year
MBM engineering college.
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