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Numerical Investigation of Laminar Forced Convection and Entropy Generation of Nanofluid in a Confined Impinging Slot Jet Using Two-Phase Mixture Model

  • Babak Yousefi-LafourakiEmail author
  • Abas RamiarEmail author
  • Ali Akbar Ranjbar
Research Paper
  • 66 Downloads

Abstract

In this article, computational fluid dynamics (CFD) simulations is used to investigate the volumetric entropy generation and heat transfer on confined impinging slot jet, with a mixture of water and Al2O3 nanoparticles as working fluid. The flow is laminar and a constant temperature is applied on the impingement surface. The governing mass and momentum equations for mixture and dispersed phase and also energy equation for mixture are solved using the finite volume method. This paper studies the effects of different geometric parameters, particle volume concentration and Reynolds number on local and average Nusselt number, stagnation point Nusselt number, entropy generation and stream function contours. The results showed that the intensity and size of the vortex structures depend on jet-to-impingement surface distance ratio (H/W), Reynolds number and particle concentrations. As H/W ratio increases, average and stagnation point Nusselt number decrease due to flow instability. By increasing Reynolds number and volume concentration, average Nusselt number and exergy loss increase due to stretching of the vortex structure in downstream direction. From the CFD results, it is found that a substantial portion of entropy generation occurs at stagnation and wall jet regions.

Keywords

CFD Vortex structure Entropy generation Stagnation region Mixture model 

List of symbols

\(\overline{C}_{\text{f}}\)

Average skin friction coefficient

\(c_{\text{p}}\)

Constant pressure-specific heat, J/kgK

H

Channel height, m

H

Convective heat transfer coefficient, W/(m2k)

dp

Particle diameter, m

dV

Volume element, m3

K

Thermal conductivity, W/mk

Nu

Nusselt number

Pr

Prandtl number

Re

Reynolds number

SGC

Volumetric entropy generation due to heat conduction and convection, W m−3 K−1

SGF

Volumetric entropy generation due to fluid friction, W m−3 K−1

\(\mathop {SG_{\text{C}} }\limits^{ \bullet }\)

Entropy generation due to heat conduction and convection, W K−1

\(\mathop {SG_{\text{F}} }\limits^{ \bullet }\)

Entropy generation due to fluid friction, W K−1

\(\mathop {SG}\limits^{ \bullet }\)

Total entropy generation, W K−1

T

Temperature, K

Tb

Bulk temperature, K

T0

Ambient temperature, K − 293 K

\(\vec{V}(u,\nu )\)

Velocity vector, m/s

U, v

Velocity components along x, y axes, respectively, m/s

W

Jet width, m

X, Y

Spatial coordinates, m

Greek symbols

\(\phi\)

Volume fraction of nanoparticles

\(\mu\)

Dynamic viscosity, Pa s

Α

Thermal diffusivity

ρ

Density, kg/m3

\(\tau\)

Wall shear stress, Pa

\(\dot{\psi }\)

Exergy loss, W

Superscripts

ave

Average at the inlet

f

Fluid

C

Continuous phase

jet

Refers to the reference (inlet) condition

K

k-th phase

m

Mixture

nf

Nanofluid properties

p

Nanoparticles

stg

Stagnation point

w

Wall

References

  1. Akbarinia A, Behzadmehr A (2008) Numerical study of laminar mixed convection of a nanofluid in horizontal tube using two-phase mixture model. Appl Therm Eng 28:717–727CrossRefGoogle Scholar
  2. Akbarinia A, Laur R (2009) Investigating the diameter of solid particles effects on a laminar nanofluid flow in a curved tube using a two phase approach. Int J Heat Fluid Flow 30:706–713CrossRefGoogle Scholar
  3. Behzadmehr A, Saffar-Avval M, Galanis N (2007) Prediction of turbulent forced convection of a nanofluid in a tube with uniform heat flux using a two phase approach. Int J Heat Fluid Flow 28:211–219CrossRefGoogle Scholar
  4. Bejan A (1987) The thrmodynamic design of heat and mass transfer processes device. Int J Heat Fluid Flow 4:258–276CrossRefGoogle Scholar
  5. Chen M, Chalupa R, West AC, Modi V (2000) High Schmidt mass transfer in a laminar impinging slot jet flow. Int J Heat Mass Transf 43:3907–3915CrossRefzbMATHGoogle Scholar
  6. Chen YC, Ma CF, Qin M, Li YX (2005) Theoretical study on impingement heat transfer with single-phase free-surface slot jets. Int J Heat Mass Transf 48:3381–3386CrossRefzbMATHGoogle Scholar
  7. Chiriac VC, Ortega A (2002) A numerical study of the unsteady flow and heat transfer in a transitional confined slot jet impinging on an isothermal surface. Int J Heat Mass Transf 45:1237–1248CrossRefzbMATHGoogle Scholar
  8. Chon CH, Kihm KD, Lee SP, Choi SUS (2005) Empirical correlation finding the role of temperature and particle size for nanofluid (Al2O3) thermal conductivity enhancement. Appl Phys Lett 85:153107–153110CrossRefGoogle Scholar
  9. Fard MH, Esfahany MN, Talaie MR (2010) Numerical study of convective heat transfer of nanofluids in a circular tube two-phase model versus single-phase model. Int Commun Heat Mass Transf 37:91–97CrossRefGoogle Scholar
  10. Ishii M, Shihibiki T Thermo-Fluid Dynamics of two- phase flow, Springer Science Business Media, Inc, 223 spring, street, New York, NY 10013, USAGoogle Scholar
  11. Kurowski L, Chmiel-Kurowska K, Thullie J (2009) Numerical simulation of heat transfer in nanofluids. Comput Aided Chem Eng 26:967–972CrossRefGoogle Scholar
  12. Lee DH, Song J, Jo MC (2004) The effects of nozzle diameter on impinging jet heat transfer and fluid flow. J Heat Transf 126(4):554–557CrossRefGoogle Scholar
  13. Lee HG, Yoon HS, Ha MY (2008) A numerical investigation on the fluid flow and heat transfer in the confined impinging slot jet in the low Reynolds number region for different channel height. Int J Heat Mass Transf 51:4055–4068CrossRefzbMATHGoogle Scholar
  14. Lee DH, Park HJ, Ligrani P (2012) Milliscale confined impinging slot jets: laminar heat transfer characteristics for an isothermal flat plate. Int J Heat Mass Transf 55:2249–2260CrossRefGoogle Scholar
  15. Lomascolo M, Colangelo G, Milanese M, Risi AD (2015) Review of heat transfer in nanofluids: conductive, convective and radiative experimental results. Renew Sustain Energy Rev 43:1182–1198CrossRefGoogle Scholar
  16. Lotfi R, Saboohi Y, Rashidi AM (2010) Numerical study of forced convective heat transfer of nanofluids: comparison of different approaches. Int J Heat Mass Transf 37:74–78CrossRefGoogle Scholar
  17. Mahian O, Mahmud S, Heris SZ (2012) Effect of uncertainties in physical properties on entropy generation between two rotating cylinders with nanofluids. J Heat Transf 134:101704CrossRefGoogle Scholar
  18. Maninen M, Taivassalo V, Kallio S (1996) On the mixture model for multiphase flow. Technical Research Center of Finland, pp. VTT Publication 288, p. 67, Espo 1996Google Scholar
  19. Masoumi N, Sohrabi N, Behzadmehr AA (2009) New model for calculating the effective viscosity of nanofluids. J Phys D Appl Phys 42:055501–055506CrossRefGoogle Scholar
  20. Nguyen CT, Galanis N, Polidori G, Fohanno S, Popa CV, Le Bechec A (2009) An experimental study of a confined and submerged impinging jet heat transfer using Al2O3–water nanofluid. Int J Therm Sci 48:401–411CrossRefGoogle Scholar
  21. Pak BC, Cho YI (1998) Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles. Exp Heat Transf 11:151–170CrossRefGoogle Scholar
  22. Rahgoshay M, Ranjbar AA, Ramiar A (2012) Laminar pulsating flow of nanofluids in a circular tube with isothermal wall. Int Commun Heat Mass Transf 39:463–469CrossRefGoogle Scholar
  23. Sheikholeslami M, Ganji DD (2017) Numerical approach for magnetic nanofluid flow in a porous cavity using CuO nanoparticles. Mater Des 120:382–393CrossRefGoogle Scholar
  24. Sheikholeslami Kandelousi M (2014) KKL correlation for simulation of nanofluid flow and heat transfer in a permeable channel. Phys Lett A 378:3331–3339CrossRefzbMATHGoogle Scholar
  25. Shuja SZ, Yilbasa BS, Budaira MO (2007) Jet impingement onto a cylindrical cavity: consideration of annular nozzle cone angles, and cavity diameter. Int J Comput Fluid Dyn 19:483–492CrossRefGoogle Scholar
  26. Vaziei P, Abouali O (2009) Numerical study of fluid flow and heat transfer for Al2O3-water nanofluid impinging jet. In: Proceedings of the 7th international conference on nanochannels, microchannels and minichannels, pp 22–24Google Scholar
  27. Yousefi-Lafouraki B, Ramiar A (2013) Laminar forced convection of a confined slot impinging jet in a converging channel. Int J Therm Sci 77:130–138CrossRefGoogle Scholar
  28. Yousefi-Lafouraki B, Ramiar A, Mohsenian S (2016) Entropy generation analysis of a confined slot impinging jet in a converging channel for a shear thinning nanofluid. Appl Therm Eng 105:675–685CrossRefGoogle Scholar

Copyright information

© Shiraz University 2018

Authors and Affiliations

  1. 1.Faculty of Mechanical EngineeringBabol Noshirvani University of TechnologyBabolIran

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