Mixed convection nanofluid flow over microscale forward-facing step — Effect of inclination and step heights

A numerical study of nanofluid flow and heat transfer of laminar mixed convection flow over a three-dimensional, horizontal microscale forward-facing step (MFFS) is reported. The effects of different step heights and the duct inclination angle on the heat transfer and fluid flow are discussed in this study. The straight and downstream walls were heated to a constant temperature and uniform heat flux respectively. The numerical results were carried out for step heights of 350 μm, 450 μm, 550 μm and 650 μm. Different inclination angles were considered to determine their effects on the flow and heat transfer. Ethylene glycol-SiO2 nanofluid is considered with a 25 nm particle diameter and 4% volume fraction. The results reveal that the Nusselt increases as the step heights increase. Additionally, no significant effect of the duct inclination angle is found on the heat transfer rate and the fluid flow.

[1]  Mohammad Mehdi Rashidi,et al.  Experimental study of nanofluid flow and heat transfer over microscale backward- and forward-facing steps , 2015 .

[2]  Chongyoup Kim,et al.  VISCOSITY AND THERMAL CONDUCTIVITY OF COPPER OXIDE NANOFLUID DISPERSED IN ETHYLENE GLYCOL , 2005 .

[3]  Haisheng Chen,et al.  Predicting thermal conductivity of liquid suspensions of nanoparticles (nanofluids) based on rheology , 2009 .

[4]  Eiyad Abu-Nada,et al.  Entropy generation due to heat and fluid flow in backward facing step flow with various expansion ratios , 2006 .

[5]  Saiied M. Aminossadati,et al.  Brownian motion of nanoparticles in a triangular enclosure with natural convection , 2010 .

[6]  Hosni I. Abu-Mulaweh,et al.  Turbulent mixed convection flow over a forward-facing step—the effect of step heights , 2005 .

[7]  Xing Zhang,et al.  Effective thermal conductivity and thermal diffusivity of nanofluids containing spherical and cylindrical nanoparticles , 2006 .

[8]  S. Patankar.  Numerical Heat Transfer and Fluid Flow , 2018, Lecture Notes in Mechanical Engineering.

[9]  D. Das,et al.  Development of new correlations for convective heat transfer and friction factor in turbulent regime for nanofluids , 2010 .

[10]  Tae-Keun Hong,et al.  Thermal conductivity of Fe nanofluids depending on the cluster size of nanoparticles , 2006 .

[11]  Rahman Saidur,et al.  A review on the performance of nanoparticles suspended with refrigerants and lubricating oils in refrigeration systems , 2011 .

[12]  N. Celi̇k,et al.  Experimental investigation of forced and mixed convection heat transfer in a foam-filled horizontal rectangular channel , 2009 .

[13]  C. T. Nguyen,et al.  New temperature dependent thermal conductivity data for water-based nanofluids , 2009 .

[14]  Seok Pil Jang,et al.  Effective viscosities and thermal conductivities of aqueous nanofluids containing low volume concentrations of Al2O3 nanoparticles , 2008 .

[15]  Haisheng Chen,et al.  Heat transfer and flow behaviour of aqueous suspensions of TiO2 nanoparticles (nanofluids) flowing upward through a vertical pipe , 2007 .

[16]  V. Sarin,et al.  Forced Convection Over a Three-Dimensional Horizontal Backward Facing Step , 2005 .

[17]  Wenhua Yu,et al.  The role of interfacial layers in the enhanced thermal conductivity of nanofluids: A renovated Hamilton–Crosser model , 2004 .

[18]  N. K. Anand,et al.  Flow Over a Three-Dimensional Horizontal Forward-Facing Step , 2007 .

[19]  B. H. Salman,et al.  Experimental and numerical study of nanofluid flow and heat transfer over microscale forward-facing step , 2014 .

[20]  M. Corcione.  Heat transfer features of buoyancy-driven nanofluids inside rectangular enclosures differentially heated at the sidewalls , 2010 .

[21]  Q. Xue,et al.  A model of thermal conductivity of nanofluids with interfacial shells , 2005 .

[22]  Bassem F. Armaly,et al.  Three-dimensional convective flow adjacent to backward-facing step: effects of step height , 2002 .

[23]  T. Chen,et al.  Mixed convection heat transfer in inclined backward-facing step flows , 1991 .

[24]  Wenhua Yu,et al.  Review and Comparison of Nanofluid Thermal Conductivity and Heat Transfer Enhancements , 2008 .

[25]  B. H. Salman,et al.  Combined convection nanofluid flow and heat transfer over microscale forward-facing step , 2014 .

[26]  K. Leong,et al.  Investigations of thermal conductivity and viscosity of nanofluids , 2008 .

[27]  Hosni I. Abu-Mulaweh,et al.  A review of research on laminar mixed convection flow over backward- and forward-facing steps , 2003 .

[28]  J. M. McCloskey,et al.  Thermal conductivity and particle agglomeration in alumina nanofluids: experiment and theory. , 2007, Physical review. E, Statistical, nonlinear, and soft matter physics.

[29]  K. Khanafer,et al.  BUOYANCY-DRIVEN HEAT TRANSFER ENHANCEMENT IN A TWO-DIMENSIONAL ENCLOSURE UTILIZING NANOFLUIDS , 2003 .

[30]  Hiroshi Iwai,et al.  The effects of duct inclination angle on laminar mixed convective flows over a backward-facing step , 2000 .

[31]  Hussein A. Mohammed,et al.  The effect of nanofluids flow on mixed convection heat transfer over microscale backward-facing step , 2012 .

[32]  K. Leong,et al.  Enhanced thermal conductivity of TiO2—water based nanofluids , 2005 .

[33]  Numerical investigations of a turbulent flow over triple forward facing step , 2010, 2010 The 2nd International Conference on Computer and Automation Engineering (ICCAE).

[34]  J. Eastman,et al.  Measuring Thermal Conductivity of Fluids Containing Oxide Nanoparticles , 1999 .

[35]  Kannan M. Munisamy,et al.  The effect of step height of microscale backward-facing step on mixed convection nanofluid flow and heat transfer characteristics , 2014 .

[36]  Yanhui Yuan,et al.  The effect of particle size on the thermal conductivity of alumina nanofluids , 2009 .

[37]  Boming Yu,et al.  A new model for heat conduction of nanofluids based on fractal distributions of nanoparticles , 2006 .

[38]  Rahman Saidur,et al.  A REVIEW ON APPLICATIONS AND CHALLENGES OF NANOFLUIDS , 2011 .

[39]  Suresh Sivan,et al.  Limits for thermal conductivity of nanofluids , 2010 .

[40]  D. Das,et al.  Experimental determination of thermal conductivity of three nanofluids and development of new correlations , 2009 .

[41]  H. Mohammed,et al.  Influence of Nanofluids on Mixed Convective Heat Transfer over a Horizontal Backward-Facing Step , 2011 .

[42]  Rahman Saidur,et al.  Convective heat transfer and fluid flow study over a step using nanofluids: A review , 2011 .

[43]  E. Abu-Nada.  Application of nanofluids for heat transfer enhancement of separated flows encountered in a backward facing step , 2008 .

[44]  G. Peterson,et al.  Transient and Steady-State Experimental Comparison Study of Effective Thermal Conductivity of Al2O3∕Water Nanofluids , 2008 .

[45]  B. Armaly,et al.  Laminar mixed convection in a duct with a backward-facing step: the effects of inclination angle and Prandtl number , 1993 .

[46]  Hongwei Xie,et al.  Thermal Conductivity of Suspensions Containing Nanosized SiC Particles , 2002 .

[47]  Hsuan-Tsung Hsieh,et al.  Turbulent separated convection flow adjacent to backward-facing step—effects of step height , 2006 .