scholarly journals Unsteady Boundary-Layer Flow over Jerked Plate Moving in a Free Stream of Viscoelastic Fluid

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Sufian Munawar ◽  
Ahmer Mehmood ◽  
Asif Ali ◽  
Najma Saleem
Keyword(s):  
Boundary Layer ◽  
Newtonian Fluid ◽  
Viscoelastic Fluid ◽  
Boundary Layer Flow ◽  
Analytic Solution ◽  
Flat Surface ◽  
Dimensionless Time ◽  
Unsteady Boundary Layer ◽  
Flow Properties ◽  
Layer Flow

This study aims to investigate the unsteady boundary-layer flow of a viscoelastic non-Newtonian fluid over a flat surface. The plate is suddenly jerked to move with uniform velocity in a uniform stream of non-Newtonian fluid. Purely analytic solution to governing nonlinear equation is obtained. The solution is highly accurate and valid for all values of the dimensionless time0≤τ<∞. Flow properties of the viscoelastic fluid are discussed through graphs.

scholarly journals Unsteady boundary layer flow of a casson fluid past an oscillating vertical plate with constant wall temperature

2015 ◽  
Vol 11 (1) ◽  
Author(s):  
Asma Khalid ◽  
Ilyas Khan ◽  
Sharidan Shafie
Keyword(s):  
Boundary Layer ◽  
Newtonian Fluid ◽  
Wall Temperature ◽  
Boundary Layer Flow ◽  
Vertical Plate ◽  
Casson Fluid ◽  
Unsteady Boundary Layer ◽  
Constant Wall Temperature ◽  
Casson Fluid Model ◽  
Layer Flow

The unsteady boundary layer flow is presented for non-Newtonian fluid flow past an oscillating vertical plate with constant wall temperature. The Casson fluid model is used to distinguish the non-Newtonian fluid behavior. The governing partial differential equations corresponding to the momentum and energy equations are transformed into dimensionless forms, by using suitable transformations. Laplace transform method is used to find the exact solutions of these equations. The expressions for shear stress in terms of skin friction and the rate of heat transfer in terms of Nusselt number are also obtained. Numerical results of velocity and temperature profiles with various values of embedded flow parameters are shown graphically and their effects are discussed in detail. 

A Numerical Study of Turbulent Boundary Layer Flow Over a Flat Surface With a Single Dimple

2000 ◽  
Author(s):  
Mark E. Kithcart ◽  
David E. Klett
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layer Flow ◽  
Flat Surface ◽  
Numerical Study ◽  
Heat Transfer Augmentation ◽  
Study Results ◽  
Turbulent Boundary Layer Flow ◽  
Layer Flow

Abstract Turbulent boundary layer flow over a flat surface with a single dimple has been investigated numerically using the FLUENT CFD software package, and compared to an experiment by Ezerskii and Shekhov [1989], which studied the same configuration. The impetus for this work developed as a result of previous studies. Kithcart and Klett [1996], and Afanas’yev and Chudnovskiy [1992], showed that dimpled surfaces enhance heat transfer comparably to surfaces with protrusion roughness elements, but with a much lower drag penalty. However, the actual physical mechanisms involved in this phenomena were only partially known prior this study. Results obtained numerically are in good agreement with the experiment, most notably the confirmation of the existence of a region of enhanced heat transfer created by interaction of the flow with the dimple. In particular, the simulation indicates that heat transfer augmentation is a consequence of the development of a stagnation flow region within the dimple geometry, and the existence of coherent vortical structures which create a periodic flow-field within and immediately downstream of the dimple. This periodicity appears to govern the magnitude of the heat transfer augmentation.

scholarly journals Analysis of Boundary Layer Flow and Heat Transfer for two Classes of Viscoelastic Fluid Over a Stretching Sheet with Heat Generation or Absorption

1970 ◽  
Vol 46 (4) ◽  
pp. 451-456 ◽  
Author(s):  
K Bhattacharyya ◽  
MS Uddin ◽  
GC Layek ◽  
W Ali Pk
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Viscoelastic Fluid ◽  
Heat Generation ◽  
Boundary Layer Flow ◽  
Stretching Sheet ◽  
Second Grade ◽  
Grade Fluid ◽  
Heat Generation Or Absorption ◽  
Layer Flow

In this paper, we obtained solutions of boundary layer flow and heat transfer for two classes of viscoelastic fluid over a stretching sheet with internal heat generation or absorption. In the analysis, we consider second-grade fluid and Walter's liquid B. The governing equations are transformed into self-similar ordinary differential equations by similarity transformations. The flow equation relating to momentum is solved analytically and then the heat equation using the Kummer's function. The analysis reveals that for the increase in magnitude of viscoelastic parameter both the velocity and temperature for a fixed point increase for second-grade fluid and both decrease for Walter's liquid B. Due to increase in Prandtl number and heat sink parameter, the thermal boundary layer thickness reduces, whereas increasing heat source parameter increases that thickness. Key words: Boundary layer flow; Heat transfer; Viscoelastic fluid; Stretching sheet; Heat generation or absorption DOI: http://dx.doi.org/10.3329/bjsir.v46i4.9590 BJSIR 2011; 46(4): 451-456

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