Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30184
Mixed Convection in a 2D-channel with a Co- Flowing Fluid Injection: Influence of the Jet Position

Authors: Ameni Mokni, Hatem Mhiri, Georges Le Palec, Philippe Bournot


Numerical study of a plane jet occurring in a vertical heated channel is carried out. The aim is to explore the influence of the forced flow, issued from a flat nozzle located in the entry section of a channel, on the up-going fluid along the channel walls. The Reynolds number based on the nozzle width and the jet velocity ranges between 3 103 and 2.104; whereas, the Grashof number based on the channel length and the wall temperature difference is 2.57 1010. Computations are established for a symmetrically heated channel and various nozzle positions. The system of governing equations is solved with a finite volumes method. The obtained results show that the jet-wall interactions activate the heat transfer, the position variation modifies the heat transfer especially for low Reynolds numbers: the heat transfer is enhanced for the adjacent wall; however it is decreased for the opposite one. The numerical velocity and temperature fields are post-processed to compute the quantities of engineering interest such as the induced mass flow rate, and the Nusselt number along the plates.

Keywords: Channel, Heat flux, Jet, Mixed convection.

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1433


[1] O. Manca, B. Morrone, S. Nardini, V. Naso, Natural convection in open channels, in: B. Sunden, G. Comini (Eds.), Computational Analysis of Convection Heat Transfer, WIT Press, Southampton, UK, 2000, pp. 235- 278.
[2] S.J. Kim, S.W. Lee, Air Cooling Technology for Electronic Equipment, CRC Press, Boca Raton, FL, 1996.
[3] A. Bejan, Shape and Structure from Engineering to Nature, Cambridge University Press, New York, 2000.
[4] G.A. Ledezma, A. Bejan, Optimal geometric arrangement of staggered vertical plates in natural convection, ASME J. Heat Transfer 119 (1997) 700-708.
[5] S. Sathe, B. Sammakia, A review of recent developments in some practical aspects of air-cooled electronic packages, ASME J. Heat Transfer 120 (1998) 830-839.
[6] A. Bejan, A.K. da Silva, S. Lorente, Maximal heat transfer density in vertical morphing channels with natural convection, Numer. Heat Transfer A 45 (2004) 135-152.
[7] A. Auletta, O.Manca, B. Morrone, V. Naso, Heat transfer enhancement by the chimney effect in a vertical isoflux channel, Int. J. Heat Mass Transfer 44 (2001) 4345-4357.
[8] A.K. da Silva, L. Gosselin, Optimal geometry of L- and C-shaped channels for maximum heat transfer rate in natural convection, Int. J. Heat Mass Transfer 48 (2005) 609-620.
[9] A. Andreozzi, A. Campo, O. Manca, Compounded natural convection enhancement in a vertical parallel-plate channel, Int. J. Thermal Sciences 47 (6) (2008) 742-748.
[10] W.B. Hall, J.D. Jackson, Laminarization of a turbulent pipe flow by buoyancy forces, ASME paper, ASME paper no. 69-HT-55 (1969).
[11] J.D. Jackson, W.B. Hall, Influence of buoyancy on heat transfer to fluids flowing in vertical tubes under turbulent conditions, in: S. Kakac, D.B. Spalding (Eds.), Turbulent Forced Convection in Channels and Bundles,Hemisphere Publishing, USA, 1979, pp. 613-640.
[12] Jiulei Wang, Jiankang Li, J.D. Jackson, A study of the influence of buoyancy on turbulent flow in a vertical plane passage, Int. J. Heat Fluid Flow 25 (2004) 420-430.
[13] K. Nakajima, K. Fukui, H. Ueda, T. Mizushina, Buoyancy effects on turbulent transport in combined free and forced convection between verticalparallel plates, Int. J. Heat Mass Transfer 23 (1980) 1325-1336.
[14] M. Miyamoto, Y. Katoh, J. Kurima, H. Saki, Turbulent free convection heat transfer from vertical parallel plates. In Heat Transfer, Vol. 4. (eds C. L. Tien, V. P.Carey and J. K. Ferrell) Hemisphere, Washington DC, 1986, pp. 1593- l598.
[15] A. Auletta, O. Manca, Heat and fluid flow resulting from the chimney effect in a symmetrically heated vertical channel with adiabatic extensions, International Journal of Thermal Sciences, 41 (2002), pp. 1101-1111.
[16] A.G. Fedorov and R.Vskanta, Turbulent natural convection heat transfer in an asymmetrically heated vertical parallel plate channel; International Journal of Heat Mass Transfer, 40 (1997), 16, pp. 3849-3860.
[17] T.A.M. Versteegh, F.T.M. Nieuwstadt., Turbulent budgets of natural convection in an infinite, differentially heated, vertical channel. International Journal of Heat and Fluid Flow, 19 (1998), pp.135-149.
[18] T.A.M. Versteegh, F.T.M. Nieuwstadt., A direct numerical simulation of natural convection between two infinite vertical differentially heated walls scaling laws and wall functions, International Journal of Heat and Mass Transfer, 42 (1999), pp.3673-3693.
[19] A.M. Dalbert, F.Penot, JL.Peube, convection naturelle laminaire dans un canal vertical chauffé ├á flux constant, International Journal of Heat and Mass Transfer, 24 (1981), 9, pp. 1463-1473.
[20] F. Penot, A.M.Dalbert, convection naturelle mixte et forcée dans un thermosiphon vertical chauffé ├á flux constant, International Journal of Heat and Mass Transfer,.26 (1983), 11, pp. 1639-1647.
[21] M. Najam, M. El Almi, M. Hasnaoui, A. Amahamid, Etude numérique de la convection mixte dans une cavité en forme de T soumis ├á un flux de chaleur constant et ventilé par le bas ├á l-aide d- un jet d-air vertical, Compte Rendu de Mecanique 330 (2002) 461-467.
[22] A. Auletta, O. Manca, Heat and fluid flow resulting from the chimney effect in a symmetrically heated vertical channel with adiabatic extensions, International Journal of Thermal Sciences 41 (2002) 1101- 1111