A small unsteady perturbation on the steady hydromagnetic boundary-layer flow past a semi-infinite plate

1970 ◽  
Vol 68 (2) ◽  
pp. 509-528 ◽  
Author(s):  
U. N. Das

AbstractThis paper is concerned with the unsteady hydromagnetic boundary-layer flow past a semi-infinite flat plate when the oncoming free stream is perturbed by an arbitrary function of time and the applied magnetic field is parallel to the plate far away from it. Following Lighthill, the two-dimensional boundary-layer equations are separated into those representing steady and unsteady parts of the flow and they have been solved in sequence. For the unsteady part of the motion two types of solutions are obtained, one for large times and the other for small times. Also the quasi-steady solution is obtained in terms of the steady solution. The skin friction and the tangential magnetic field at the plate are calculated.

1969 ◽  
Vol 91 (4) ◽  
pp. 632-648 ◽  
Author(s):  
T. K. Fannelop ◽  
P. C. Smith

A theoretical analysis is presented for three-dimensional laminar boundary-layer flow about slender conical vehicles including the effect of transverse surface curvature. The boundary-layer equations are solved by standard finite difference techniques. Numerical results are presented for hypersonic flow about a slender blunted cone. The influences of Reynolds number, cone angle, and mass transfer are studied for both symmetric flight and at angle-of-attack. The effects of transverse curvature are substantial at the low Reynolds numbers considered and are enhanced by blowing. The crossflow wall shear is largely unaffected by transverse curvature although the peak velocity is reduced. A simplified “channel flow” analogy is suggested for the crossflow near the wall.


1982 ◽  
Vol 5 (2) ◽  
pp. 377-384 ◽  
Author(s):  
D. B. Ingham ◽  
L. T. Hildyard

The Blasius boundary layer on a flat plate in the presence of a constant ambient magnetic field is examined. A numerical integration of the MHD boundary layer equations from the leading edge is presented showing how the asymptotic solution described by Sears is approached.


1968 ◽  
Vol 35 (2) ◽  
pp. 424-426 ◽  
Author(s):  
T. K. Fannelop

The effects of periodic transverse velocity fluctuations are investigated for boundary-layer flow over a flat plate. The method used is a perturbation expansion of the three-dimensional boundary-layer equations in terms of the small transverse velocity component. The equations are reduced to similarity form by means of suitable transformations. The second-order terms are expressed in terms of the first-order (Blasius) variables and are found to increase linearly with the streamwise coordinate. The present heat-transfer solution agrees with the more qualitative results of Persen. The derived velocity profiles are in exact agreement with the results of Crow’s more elaborate analysis based on the Navier-Stokes equations.


2015 ◽  
Vol 70 (4) ◽  
pp. 225-233 ◽  
Author(s):  
Tasawar Hayat ◽  
Taseer Muhammad ◽  
Sabir Ali Shehzad ◽  
Ahmed Alsaedi

AbstractIn this article we investigated the characteristics of Brownian motion and thermophoresis in the magnetohydrodynamic (MHD) three-dimensional boundary layer flow of an incompressible Jeffrey fluid. The flow is generated by a bidirectional stretching surface. Fluid is electrically conducting in the presence of a constant applied magnetic field. Mathematical formulation of the considered flow problem is made through the boundary layer analysis. A newly proposed boundary condition requiring zero nanoparticle mass flux is employed in the flow analysis of Jeffrey fluid. The governing nonlinear boundary layer equations are reduced into the nonlinear ordinary differential systems through appropriate transformations. The resulting systems have been solved for the velocities, temperature, and nanoparticle concentration expressions. The contributions of various interesting parameters are studied graphically. The values of the Nusselt number are computed and examined.


1954 ◽  
Vol 5 (1) ◽  
pp. 73-84 ◽  
Author(s):  
J. Wilkinson

SummaryThe three-dimensional boundary layer flow defined by the external irrotational velocity components U = x (ξ), V = αη, where α is a small positive parameter, is investigated with the aid of the boundary layer equations of Howarth. When X(ξ) = ξm a solution exact to the first power in α is found. A Pohlhausen method is then developed for any function x (ξ) and applied to the cases in which x (ξ) = ξm and x (ξ)=i-ξ.


2012 ◽  
Vol 15 (6) ◽  
pp. 585-593
Author(s):  
M. Jana ◽  
S. Das ◽  
S. L. Maji ◽  
Rabindra N. Jana ◽  
S. K. Ghosh

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