Boundary Layer Theory: New Analytical Approximations with Error and Lambert Functions for Flat Plate without/with Suction

In this work, we investigated the problem of the boundary layer suction on a flat plate with null incidence and without pressure gradient. There is an analytical resolution using the Bianchini approximate integral method. This approximation has been achieved by Lambert or Error functions for boundary layer profiles with uniform suction, even in the case without suction. Based on these new laws, we brought out analytical expressions of several boundary layer features. This gives a necessary data to suction effect modeling for boundary layer control. To recommend our theoretical results, we numerically studied the boundary layer suction on a porous flat plate equipped with trailing edge flap deflected to 40°. We showed that this flap moves the stagnation point on the upper surface, resulting to avoid the formation of the laminar bulb of separation. Good agreement was obtained between the new analytical laws, the numerical results (CFD Fluent), and the literature results.

Hall Effects on Unsteady Magneto Hydrodynamic Convection Flow of Nanofluids Past a Rotating Porous Plate

The effects of Hall current are considered for the convective rotational current free of nanofluid magnetohydrodynamics (copper and alumina) in a permeable medium with a vertical porous flat plate, semi-infinite rotation with stable state of the heat source and convection limit. The slip rate is expected to oscillate over time with a constant frequency so that the boundary layer solutions are of the equivalent oscillating type. The equations to regulate the flow are analytically solved by perturbation estimation. The effects of different parameters on the flow are investigated by means of diagrams and tables