Effects of parietal suction and injection on the stability of the Blasius boundary-layer flow over a permeable, heated plate

2021 ◽  
Vol 6 (11) ◽  
Author(s):  
Mushrifah Al-Malki ◽  
Zahir Hussain ◽  
Stephen Garrett ◽  
Sophie Calabretto
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Heated Plate ◽  
Blasius Boundary Layer ◽  
Layer Flow ◽  
The Stability

The stability of boundary-layer flow over single-and multi-layer viscoelastic walls

1988 ◽  
Vol 196 ◽  
pp. 359-408 ◽  
Author(s):  
K. S. Yeo
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Single Layer ◽  
Viscous Sublayer ◽  
Rigid Base ◽  
Theoretical Treatment ◽  
Dynamical Condition ◽  
Compliant Walls ◽  
Layer Flow ◽  
The Stability

In this paper, we are concerned with the linear stability of zero pressure-gradient laminar boundary-layer flow over compliant walls which are composed of one or more layers of isotropic viscoelastic materials and backed by a rigid base. Wall compliance supports a whole host of new instabilities in addition to the Tollmien-Schlichting mode of instability, which originally exists even when the wall is rigid. The perturbations in the flow and the compliant wall are coupled at their common interface through the kinematic condition of velocity continuity and the dynamical condition of stress continuity. The disturbance modes in the flow are governed by the Orr-Sommerfeld equation using the locally-parallel flow assumption, and the response of the compliant layers is described using a displacement-stress formalism. The theoretical treatment provides a unified formulation of the stability eigenvalue problem that is applicable to compliant walls having any finite number of uniform layers; inclusive of viscous sublayer. The formulation is well suited to systematic numerical implementation. Results for single- and multi-layer walls are presented. Analyses of the eigenfunctions give an insight into some of the physics involved. Multi-layering gives a measure of control over the stability characteristics of compliant walls not available to single-layer walls. The present study provides evidence which suggests that substantial suppression of disturbance growth may be possible for suitably tailored compliant walls.

scholarly journals The centrifugal instability of the boundary-layer flow over slender rotating cones

2014 ◽  
Vol 755 ◽  
pp. 274-293 ◽  
Author(s):  
Z. Hussain ◽  
S. J. Garrett ◽  
S. O. Stephen
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Rotating Disk ◽  
Alternative Formulation ◽  
Centrifugal Instability ◽  
Half Angle ◽  
Layer Flow ◽  
The Stability ◽  
Experimental And Theoretical Studies ◽  
Numerical Approaches

AbstractExisting experimental and theoretical studies are discussed which lead to the clear hypothesis of a hitherto unidentified convective instability mode that dominates within the boundary-layer flow over slender rotating cones. The mode manifests as Görtler-type counter-rotating spiral vortices, indicative of a centrifugal mechanism. Although a formulation consistent with the classic rotating-disk problem has been successful in predicting the stability characteristics over broad cones, it is unable to identify such a centrifugal mode as the half-angle is reduced. An alternative formulation is developed and the governing equations solved using both short-wavelength asymptotic and numerical approaches to independently identify the centrifugal mode.

scholarly journals MHD natural convection boundary-layer flow over a semi-infinite heated plate with arbitrary inclination

2020 ◽  
Vol 13 (3) ◽  
pp. 1007-1015
Author(s):  
Azhar Ali Zafar ◽  
◽  
Khurram Shabbir ◽  
Asim Naseem ◽  
Muhammad Waqas Ashraf
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Boundary Layer Flow ◽  
Convection Boundary Layer ◽  
Heated Plate ◽  
Convection Boundary ◽  
Layer Flow

scholarly journals Magnetohydrodynamic cross-field boundary layer flow

1982 ◽  
Vol 5 (2) ◽  
pp. 377-384 ◽  
Author(s):  
D. B. Ingham ◽  
L. T. Hildyard
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Asymptotic Solution ◽  
Boundary Layer Flow ◽  
Leading Edge ◽  
Field Boundary ◽  
Boundary Layer Equations ◽  
Mhd Boundary Layer ◽  
Blasius Boundary Layer ◽  
Layer Flow

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.

Vortex Instability in Buoyancy-Induced Flow over Inclined Heated Surfaces in Porous Media

1979 ◽  
Vol 101 (4) ◽  
pp. 660-665 ◽  
Author(s):  
C. T. Hsu ◽  
Ping Cheng
Keyword(s):  
Boundary Layer ◽  
Inclination Angle ◽  
Boundary Layer Flow ◽  
Heated Surface ◽  
Wave Number ◽  
Heated Plate ◽  
Local Similarity ◽  
Linear Temperature ◽  
Vortex Instability ◽  
Layer Flow

A linear stability analysis is performed for the study of the onset of vortex instability in free convective flow over an inclined heated surface in a porous medium. The undisturbed state is assumed to be the steady two-dimensional buoyancy-induced boundary layer flow which is characterized by a non-linear temperature profile. By a scaling argument, it is shown that the length scales of disturbances are smaller than those for the undisturbed boundary layer flow, thus, confirming the so-called “bottling effects” whereby the disturbances are confined within the boundary layer. By neglecting the lowest order terms in the three-dimensional disturbances equations, the simplified equations are solved based on the local similarity approximations, wherein the disturbances are assumed to have a weak dependence in the streamwise direction. The resulting eigenvalue problem is solved numerically. The critical parameter and the critical wave number of disturbances at the onset of vortex instability are computed for different prescribed wall temperature distribution of the inclined surface. It is found that the larger the inclination angle with respect to the vertical, the more susceptible is the flow for the vortex mode of disturbances; and in the limit of zero inclination angle (i.e., a vertical heated plate) the flow is stable for this form of disturbances.

Sign in / Sign up

Export Citation Format

Share Document