We investigate numerically the transition to turbulence in a flat-plate boundary layer controlled by electromagnetic forces. The fluid considered is incompressible, Newtonian and low electrically conductive. Similar to boundary layer suction, when applying a steady, wall-parallel, and streamwise oriented Lorentz force, the Blasius velocity profile is transformed to an exponential one. Since the...

We consider free convection near a semi-innnite vertical at plate. This problem is singularly perturbed with perturbation parameter Gr, the Grashof number. Our aim is to nd numerical approximations of the solution in a bounded domain, which does not include the leading edge of the plate, for arbitrary values of Gr 1. Thus, we need to determine values of the velocity components and temperature w...

In the fully rough regime, proposed models predict a scaling for roughness heat-transfer coefficient, e.g. Stanton number ${St}_k \sim (k^+)^{-p} {Pr}^{-m}$ where exponent values $p$ and $m$ are model dependent, giving diverse predictions. Here, $k^+$ is Reynolds ${Pr}$ Prandtl number. To clarify this ambiguity, we conduct direct numerical simulations of forced convection over three-dimensional...

We consider the incompressible stationary flow of a fluid past a semi-infinite flat plate. This is a very old and well studied problem and is discussed in most introductory texts on fluid mechanics. Indeed, an easy scaling argument shows that far downstream the flow should be to leading order described by the so called Blasius solution, and this has been confirmed to good precision by experimen...

Abstract An explicit approximate solution is obtained for the extended Blasius equation subject to its well-known classical boundary conditions, where viscosity coefficient assumed be positive and temperature-dependent, which arises in several important layer problems fluid dynamics. This problem extends a previous by Cortell (Appl Math Comput 170:706–710, 2005) when constant, numerical was obt...

Polyethylene pipes are widely used in the trickle irrigation system. The main objective of this research work is to determine friction factors for type pipes. A field study was carried out on two laterals each which about 240 m length. One line had 18.5 mm inside diameter, other consisted parts, first 21.5 diameter and 17 diameter. measured factor compared by corresponding given conventional fo...

the purpose of this study is to demonstrate the potential of imperialist competitivealgorithm (ica) for solving blasius dierential equation. this algorithm is inspiredby competition mechanism among imperialists and colonies and has demonstrated excellentcapabilities such as simplicity, accuracy, faster convergence and better global optimumachievement in contrast to other evolutionary algorithms...