Sains Malaysiana 41(10)(2012): 1271–1279

Stagnation-point Flow and Mass Transfer with Chemical Reaction Past a Permeable Stretching/Shrinking Sheet in a Nanofluid

(Aliran Titik Genangan dan Pemindahan Jisim dengan Tindak Balas Kimia Terhadap Helaian

Meregang / Mengecut Telap dalam Nanobendalir)

Natalia C. Rosca, Teodor Grosan, Ioan Pop*

Faculty of Mathematics and Computer Science, Babes-Bolyai University, 400084 Cluj-Napoca, Romania

Diserahkan: 19 April 2012 / Diterima: 15 Mei 2012

ABSTRACT

A numerical study has been conducted to investigate the steady forced convection stagnation point-flow and mass transfer past a permeable stretching/shrinking sheet placed in a copper (Cu)- water based nanofluid. The system of partial differential equations is transformed, using appropriate transformations, into two ordinary differential equations, which are solved numerically using bvp4c function from Matlab. The results are obtained for the reduced skin-friction and reduced Sherwood number as well as for the velocity and concentration profiles for some values of the governing parameters. These results indicate that dual solutions exist for the shrinking sheet case (λ < 0). It is shown that for a regular fluid (f = 0) a very good agreement exists between the present numerical results and those reported in the open literature.

Keywords: Mass transfer; nanofluid; permeable sheet; stretching/shrinking sheet

ABSTRAK

Suatu kajian berangka telah dijalankan bagi mengkaji aliran titik genangan olakan paksa mantap dan pemindahan jisim terhadap helaian meregang/mengecut telap di dalam nanobendalir berasaskan air-kuprum(Cu). Sistem persamaan pembezaan separa dijelmakan kepada dua persamaan pembezaan biasa dengan penjelmaan yang bersesuaian, yang diselesaikan secara berangka menggunakan fungsi bvp4c daripada perisian Matlab. Keputusan diperoleh bagi geseran kulit terturun dan nombor Sherwood terturun, serta profil-profil halaju dan kepekatan bagi beberapa nilai parameter menakluk. Keputusan menunjukkan yang penyelesaian dual wujud bagi kes helaian mengecut  (λ < 0). Didapati bahawa bagi bendalir biasa atau asas (f = 0), hasil perbandingan yang sangat baik diperoleh antara keputusan berangka terkini dengan keputusan yang dilaporkan oleh penyelidik terdahulu.

Kata kunci: Helaian meregang/mengecut; helaian telap; nanobendalir; pemindahan jisim

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*Pengarang untuk surat-menyurat; email: popm.ioan@yahoo.co.uk