## THERMAL SCIENCE

International Scientific Journal

### Thermal Science - Online First

online first only
### An analytical study on the entropy generation in flow of a generalized Newtonian fluid

**ABSTRACT**

In this study, an analytical investigation on pressure driven flow of Powell- Eyring fluid is conducted to understand the irreversibilities due to heat transfer and viscous heating. The flow between infinitely long parallel plates is considered as fully developed and laminar with constant properties and subjected to symmetrical heat fluxes from solid boundaries. The internal heating due to viscous friction accompanies external heat transfer, that is, viscous dissipation term is to be involved in the energy equation. As a crosscheck, accuracy of analytical solutions is confirmed by a predictor-corrector numerical scheme with variable step size.

**KEYWORDS**

PAPER SUBMITTED: 2019-07-01

PAPER REVISED: 2019-08-20

PAPER ACCEPTED: 2019-08-22

PUBLISHED ONLINE: 2019-10-06

- Morrison, F.A., Understanding Rheology, Oxford University Press, New York, USA, 2001.
- Tso, C.P., et al., Viscous Dissipation Effects of Power-Law Fluid Flow within Parallel Plates with Constant Heat Fluxes, J. Non-Newtonian Fluid Mech., 165 (2010), pp. 525-630.
- Galindo-Rosales, F.J., et al, How Dr. Malcom M. Cross may have tackled the development of "An Apparent Viscosity Function for Shear Thickening Fluids", J. Non-Newtonian Fluid Mech., 166 (2011), pp. 1421-1424.
- Georgiou, G.C., The Time-Dependent, Compressible Poiseuille and Extrudate-Swell Flows of a Carreau Fluid with Slip at the Wall, J. Non-Newtonian Fluid Mech., 109 (2003), pp. 93-114.
- Yasuda, K., et al, Shear-Flow Properties of Concentrated Solutions of Linear and Star-Branched Polystyrenes, Rheol. Acta, 20(2) (1981), pp. 163-178.
- Kushwaha, H.M., Sahu, S.K., Effects of Viscous Dissipation and Rarefaction on Parallel Plates with Constant Heat Flux Boundary Conditions, Chem. Eng. Technol., 38 (2015), pp. 1-12.
- Aydın, O., Avcı, M., Viscous-Dissipation Effects on the Heat Transfer in a Poiseuille Flow, Applied Energy, 83 (2006), pp. 495-512.
- Bejan, A., A Study of Entropy Generation in Fundamental Convective Heat Transfer, J. Heat Trans. 101 (1979), pp. 718-725.
- Hooman, K., Entropy Generation for Microscale Forced Convection: Effects of Different Thermal Boundary Conditions, Velocity Slip, Temperature Jump, Viscous Dissipation, and Duct Geometry, Int. Commun. Heat Mass, 34 (2007), pp. 945-957.
- Shojaeian, M., Koşar, A., Convective Heat Transfer and Entropy Generation Analysis on Newtonian and non-Newtonian Fluid Flows Between Parallel-Plates under Slip Boundary Conditions, Int. J. Heat Mass Tran., 70 (2014), pp. 664-673.
- Matin, M.H., Khan, W.A., Entropy Generation Analysis of Heat and Mass Transfer in Mixed Electrokinetically and Pressure Driven Flow through a Slit Microchannel, Energy, 56 (2013), pp. 207-217.
- Hina, S., Mustafa, M., Hayat, T., Alsaedi, A., Peristaltic Transport of Powell-Eyring Fluid in a Curved Channel with Heat/Mass Transfer and Wall Properties, Int. J. Heat Mass Tran., 101 (2016), pp. 156-155.
- Yoon, H.K., Ghajar, A.J., A Note on the Powell-Eyring Fluid Model, Int. Comm. Heat Mass Transfer, 14 (1987), pp. 381-390.
- Aksoy, Y., Effects of Couple Stresses on the Heat Transfer and Entropy Generation Rates for a Flow between Parallel Plates with Constant Heat Flux, Int. J. Therm. Sci., 107 (2016), pp. 1-12.
- Nayfeh, A. H., Perturbation Methods, John Wiley and Sons, New York, USA, 2000.
- Kays, W., et al., Heat and Mass Transfer McGraw-Hill, New York, USA, 2005.
- Bejan, A., Entropy Generation Minimization, CRC Press, Boca Raton, FL, USA, 1996.