estimation of boundary-layer flow of a nanofluid past a stretching sheet：a revised model.pdfVIP

596 2016,28(4):596-602 DOI: 10.1016/S1001-6058(16)60663-7 Estimation of boundary-layer flow of a nanofluid past a stretching sheet: A * revised model 1 2 3 4 Naeema ISHFAQ , Zafar Hayat KHAN , Waqar Ahmad KHAN , Richard J. CULHAM 1. School of Mathematical Sciences, Peking University, Beijing 100871, China, E-mail: sanam_143_6@ 2. Department of Mathematics, University of Malakand, Dir (Lower), Khyber Pakhtunkhwa, Pakistan 3. Department of Mechanical and Industrial Engineering, College of Engineering, Majmaah University, Al Majma′ah, Saudi Arabia 4. Department of Mechanical Engineering, University of Waterloo, Waterloo, Ontario, Canada (Received October 6, 2014, Revised April 27, 2015) Abstract: The previous model for the boundary layer nanofluid flow past a stretching surface with a specified nanoparticle volume fraction on the surface is revisited. The major limitation of the previous model is the active control of the nanoparticle volume fraction on the surface. In a revised model proposed in this paper, the nanoparticle volume fraction on the surface is passively contro- lled, which accounts for the effects of both the Brownian motion and the thermophoresis under the boundary condition, whereas the Buongiorno’s model considers both effects in the governing equations. The assumption of zero nanoparticle flux on the surface makes the model physically more realistic. In the revised model, the dimensionless heat transfer rates are found to be higher whereas the dimensionless mass transfer rates are identically zero due to the passive boundary condition. It is also found th