Sains Malaysiana 39(6)(2010): 1035–1039

Aliran Lapisan Sempadan Bersebelahan Plat Tegak  dengan Suhu Permukaan Malar

(Boundary Layer Flow Adjacent to a Vertical Plate with Constant Surface Temperature)

Anuar Ishak*

Pusat Pengajian Sains Matematik

Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor, Malaysia

Diserahkan: 30 Disember 2008 / Diterima: 20 Mei 2010

ABSTRAK

Pembentukan lapisan sempadan halaju dan terma yang dirangsang oleh aliran bebas bersebelahan plat tegak dengan suhu permukaan malar dikaji. Persamaan-persamaan menakluk dalam bentuk persamaan pembezaan separa diturunkan kepada persamaan-persamaan pembezaan biasa dengan penjelmaan keserupaan, sebelum diselesaikan secara berangka. Kedua-dua aliran membantu dan aliran menentang dipertimbangkan. Didapati bahawa penyelesaian adalah unik bagi aliran membantu, manakala penyelesaian dual wujud bagi aliran menentang. Kadar pemindahan haba pada permukaan didapati meningkat dengan peningkatan kedua-dua daya keapungan dan nombor Prandtl.

Kata kunci: Lapisan sempadan; pemindahan haba; penyelesaian dual; penyelesaian keserupaan

ABSTRACT

The development of velocity and thermal boundary layers induced by a free stream adjacent to a vertical plate with constant surface temperature was studied. The governing partial differential equations were reduced to ordinary ones by a similarity transformation, before being solved numerically. Both assisting and opposing flows were considered. It was found that the solution was unique for the assisting flow, while dual solutions were found to exist for the opposing flow. The heat transfer rate at the surface was found to increase with both the buoyancy force and the Prandtl number.

Keywords: Boundary layer; dual solutions; heat transfer; similarity solution

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*Pengarang untuk surat-menyurat; email: anuarishak@yahoo.com