International Scientific Journal


The present work is a contribution to study of convective heat transfer coefficient inside a rectangular channel with corrugated walls. Triangular, square and rectangular shaped configurations were studied for a range of geometric parameters during simulation. The Navier-Stokes equations were numerically solved using the finite volume method through the Easy CFD_G package code in its V.4.1.0 version. With prescribed temperatures and velocities, the model predicts the behavior of the airflow inside the device. The temperature and velocity distributions are first predicted. From these distributions, the convective heat transfer coefficients along the surface of the objects placed inside the system are determined. Also, from the pressure distribution, the pressure drops along the channel are predicted. The results show that the triangular corrugated-shaped configuration with h = 5 [cm] and α = β = 60° enable to obtain the best value of convective heat transfer coefficient on the surface of the objects which is 2.70 [Wm-2°C-1] resulting in a pressure drop of 0.11 [Pa], while for parallel-plate channel configuration this same coefficient is 1.12 [Wm-2°C-1]. The energy balance enabled to conclude that the energy gain by convection air/objects is superior to the air pump energy to overcome the pressure drop.
PAPER REVISED: 2016-01-23
PAPER ACCEPTED: 2016-01-23
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  1. Edoun, M., et al., Etat de la pratique du séchage de quelques fruits et légumes à petite échelle dans le Sud Cameroun, Fruits, 66 (2010), 1, pp.1-12.
  2. Ratti, C., Crapiste, G.H., Determination of heat transfer coefficients during drying of foodstuffs, Journal of Food Processing Engineering, 18 (1995), pp. 41-53.
  3. Anwar, S.I., Tiwari, G.N., Evaluation of convective heat transfer coefficient in crop drying under open sun drying, Energy Conversion. Management, 42 (2001),5, pp. 627-637.
  4. Goyal, R.K., Tiwari, G.N., Heat and mass transfer relation for crop drying, Drying Technology, 16 (1998), pp. 1741-1754.
  5. Anwar, S.I., Tiwari, G.N., Convective heat transfer coefficient of crop in forced convection drying: An experimental study, Energy Conversion Management, 42 (2001), pp. 1687-1698.
  6. Togrul, I.T., Convective heat transfer coefficient of some fruits under open sun drying conditions, Journal of Food Technology, 3 (2005), 1, pp. 10-14.
  7. Akpinar, E.K., Evaluation of convective heat transfer coefficient of various crops in cyclone type dryer, Energy Conversion Management, 46 (2005), pp. 2439-2454.
  8. Togrul, I.T., Pehlivan, D., Modeling of thin layer drying kinetics of some fruits under open-air sun drying process, Journal of Food Processing Engineering, 65 (2004), pp. 413-425.
  9. Kaya, A., et al., Numerical modeling of heat and mass transfer during forced convection drying of rectangular moist objects, International Journal of Heat and Mass Transfer, 49 (2006), pp. 3094-3103.
  10. Kaya, A., et al., Experimental and numerical investigation of heat and mass transfer during drying of Hayward kiwi fruits (Actinidia Deliciosa Planch), Journal of Food Engineering, 88 (2008), pp. 323-330.
  11. Chandra Mohan, V.P., Talukdar, P., Three dimensional numerical modeling of simultaneous heat and moisture transfer in a moist object subjected to convective drying, International Journal of Heat and Mass Transfer, 53 (2010), pp. 4638-4650.
  12. Taymaz, I., et al., Numerical investigation of incompressible fluid flow and heat transfer across a bluff body in a channel flow, Thermal Science Journal, 19 (2015), 2, pp. 537-547.
  13. Hong, S.W., Bergles, A.E., Augmentation of laminar flow heat transfer in tubes by means of twisted-tape inserts, ASME, Journal of Heat Transfer, 98 (1976), pp. 251-256.
  14. Ray, S., Date, A.W., Laminar flow and heat transfer through square duct with twisted tape insert, International journal of heat fluid flow, 22 (2001), pp. 460-472.
  15. Gui, X., et al., Analysis on three-dimensional flow and heat transfer in a cross wavy primary surface recuperator for a micro-turbine system, Thermal Science Journal, 19 (2015), 2, pp. 489-496.
  16. Naga Sarada, S., et al., Enhancement of heat transfer using varying width twisted tape inserts, International Journal of Engineering Sciences and Technology, 2 (2010), pp.107-118.
  17. Ahmed-Zaïd, A., et al., Amélioration des performances des capteurs solaires plans à air : application au séchage de l'oignon jaune et du hareng, Revue des Energies Renouvelables, 4 (2001), pp. 69-78.
  18. Youcef-Ali, S., Study and optimization of the thermal performances of the offset rectangular plate fin absorber plates, with various glazing, Renewable Energy, 30 (2005), pp. 271-280.
  19. Lanjewar, A., et al., Heat transfer and friction in solar air heater duct with W-shaped rib roughness on absorber plate, Energy, 36 (2011),7, pp. 4531-4541.
  20. António, M.G.L., EasyCFD_G V4.1.0 User's Manual, 2012.
  21. Launder, B.E., Spalding, D.B., Mathematical models of turbulence, Academic Press London and New York, ISBN 0-12-438050-6, 1972.
  22. Launder, B.E., Spalding, D.B., The numerical computer of Turbulent Flows, Computational Methods Applied in Mechanical Engineering, 3 (1974), pp. 269-289.
  23. Djilali, N., et al., Calculation of convective heat transfer in recirculating turbulent flows using various Near-wall turbulence models. Numerical Heat Transfert Part A, 16 (1987), pp.189-212.
  24. Rivier, M., et al., Le séchage des mangues : Guide pratique, Editions Quae, CTA, Paris, 2009.

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