Sains Ma1aysiana 33(1): 15-27 (2004) Pengajian Kuantitatif/
Quantitative Studies
Unsteady Mixed Convection near the Forward Stagnation
Point of a Two-Dimensional Symmetric Body
Prescribed with a Constant Wall Heat Flux
Roslinda Nazar
School of Mathematical Sciences
Faculty of Science & Technology
Universiti Kebangsaan Malaysia
43600 UKM Bangi, Selangor D.E., Malaysia
Ioan Pop
Faculty of Mathematics
University of Cluj
R-3400 Cluj, CP 253, Romania
ABSTRAK
Dalam makalah ini, kajian terhadap masalah aliran lapisan sempadan olakan campuran tak mantap berhampiran titik genangan ke depan bagi suatu jasad simetri dua dimensi dengan kadar fluks haba yang seragam dibincangkan. Tujuan utama kajian ini adalah untuk mengenal pasti situasi di mana penyelesaian dual bagi aliran keadaaan mantap boleh ditentukan, apabila aliran menentang berlaku. Di samping itu, dalam kajian ini juga didapati bahawa terdapat peralihan yang licin dari aliran awal tak mantap (bagi masa yang pendek) ke aliran akhir mantap (bagi masa yang panjang).
ABSTRACT
The unsteady mixed convection boundary layer flow near the forward stagnation point of a two-dimensional symmetric body prescribed by a uniform heat flux rate is studied in this paper. The main aim of the investigation is to identify situations in which dual solutions for the steady-state flow can be determined when the flow is opposing. It is also shown that there is a smooth transition from the unsteady initial flow (short time) to the final steady state flow (large time).
RUJUKAN/REFERENCES
Amin, N. & Riley, N. 1995. Mixed convection at a stagnation point. Q. J. Mech. Appl. Math. 48: 111-121.
Bejan, A. & Kraus, A.D. (eds.) 2003. Heat Transfer Handbook. New York: John Wiley.
Cebeci, T. & Bradshaw, P. 1988. Physical and Computational Aspects of Convective Heat Transfer. New York: Springer.
Gebhart, B. 1979. Buoyancy induced fluid motions characteristic of applications in technology. J. Fluids Engng. 101: 5-28.
Joshi, Y. 1990. Transient natural convection flows. In Cheremisionoff, N.P. (ed.), Encyclopedia of Fluid Mechanics. Houston: Gulf Publishing Company. 8: 477-533.
Nazar, R., Amin, N. & Pop, I. 2003. Unsteady mixed convection near the forward stagnation point of a two-dimensional symmetric body. Int. Comm. Heat Mass Transfer 30: 673-682.
Nazar, R., Amin, N. & Pop, I. 2004. Mixed convection boundary layer flow from a horizontal circular cylinder with a constant surface heat flux. Heat and Mass Transfer 40: 219-227.
Pop, I. 1997. Transient heat transfer boundary layers. Proc. Int. Symposium on Transient Convective Heat Transfer (padet, J. & Arinc, F. (eds.) New York: Begell House. 3-17.
Pop, I., Ingham, D.B. & Merkin, J .H. 1998. Transient convective heat transfer in external flow. In Tyvand, P (ed.), Advances in Fluid Mechanics: Time-Dependent Nonlinear Convection. Vol. 19, Southampton: Computational Mechanics Publications. 83-114.
Pop, I. & Ingham, D.B. 2001. Convective Heat Transfer: Mathematical and Computational Modelling of Viscous Fluids and Porous Media. Oxford: Pergamon.
Riley, N. 1975. Unsteady laminar boundary layers. SIAM Review 17: 274-297.
Seshadri, R., Sreeshylan, N. & Nath, G. 2002. Unsteady mixed convection flow in the stagnation region of a heated vertical plate due to impulsive motion. Int. J. Heat Mass Transfer 45: 1345-1352.
Telionis, D.P. 1981. Unsteady Viscous Flows. New York: Springer.
|