Selective enhancement of oblique waves caused by finite amplitude second mode in supersonic boundary layer

2017 ◽  
Vol 38 (8) ◽  
pp. 1109-1126 ◽  
Author(s):  
Cunbo Zhang ◽  
Jisheng Luo
Keyword(s):  
Boundary Layer ◽  
Finite Amplitude ◽  
Supersonic Boundary Layer ◽  
Oblique Waves ◽  
Second Mode ◽  
Selective Enhancement

On the interaction between first‐ and second‐mode waves in a supersonic boundary layer

1991 ◽  
Vol 3 (12) ◽  
pp. 3014-3020 ◽  
Author(s):  
L. Maestrello ◽  
A. Bayliss ◽  
R. Krishnan
Keyword(s):  
Boundary Layer ◽  
Supersonic Boundary Layer ◽  
Second Mode

Oblique-mode breakdown and secondary instability in supersonic boundary layers

1994 ◽  
Vol 273 ◽  
pp. 323-360 ◽  
Author(s):  
Chau-Lyan Chang ◽  
Mujeeb R. Malik
Keyword(s):  
Boundary Layer ◽  
Rapid Growth ◽  
Plate Boundary ◽  
Streamwise Vortex ◽  
Supersonic Boundary Layer ◽  
Secondary Instability ◽  
Single Frequency ◽  
Small Scale ◽  
Instability Mechanism ◽  
Oblique Waves

Laminar–turbulent transition mechanisms for a supersonic boundary layer are examined by numerically solving the governing partial differential equations. It is shown that the dominant mechanism for transition at low supersonic Mach numbers is associated with the breakdown of oblique first-mode waves. The first stage in this breakdown process involves nonlinear interaction of a pair of oblique waves with equal but opposite angles resulting in the evolution of a streamwise vortex. This stage can be described by a wave–vortex triad consisting of the oblique waves and a streamwise vortex whereby the oblique waves grow linearly while nonlinear forcing results in the rapid growth of the vortex mode. In the second stage, the mutual and self-interaction of the streamwise vortex and the oblique modes results in the rapid growth of other harmonic waves and transition soon follows. Our calculations are carried all the way into the transition region which is characterized by rapid spectrum broadening, localized (unsteady) flow separation and the emergence of small-scale streamwise structures. The r.m.s. amplitude of the streamwise velocity component is found to be on the order of 4–5 % at the transition onset location marked by the rise in mean wall shear. When the boundary-layer flow is initially forced with multiple (frequency) oblique modes, transition occurs earlier than for a single (frequency) pair of oblique modes. Depending upon the disturbance frequencies, the oblique mode breakdown can occur for very low initial disturbance amplitudes (on the order of 0.001% or even lower) near the lower branch. In contrast, the subharmonic secondary instability mechanism for a two-dimensional primary disturbance requires an initial amplitude on the order of about 0.5% for the primary wave. An in-depth discussion of the oblique-mode breakdown as well as the secondary instability mechanism (both subharmonic and fundamental) is given for a Mach 1.6 flat-plate boundary layer.

Experimental study of natural disturbances of a supersonic boundary layer on a swept-wing model with periodic roughness

2020 ◽  
Author(s):  
A. A. Yatskikh ◽  
A. V. Panina ◽  
Yu. G. Yermolaev ◽  
A. D. Kosinov ◽  
N. V. Semionov
Keyword(s):  
Boundary Layer ◽  
Experimental Study ◽  
Supersonic Boundary Layer ◽  
Natural Disturbances ◽  
Swept Wing ◽  
Wing Model

Influence of coating permeability and roughness on supersonic boundary layer stability

2016 ◽  
Author(s):  
V. I. Lysenko ◽  
S. A. Gaponov ◽  
B. V. Smorodsky ◽  
Yu. G. Yermolaev ◽  
A. D. Kosinov ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Supersonic Boundary Layer ◽  
Boundary Layer Stability

Supersonic boundary layer on a plate. Comparison of calculation and experiment

1998 ◽  
Vol 33 (6) ◽  
pp. 864-875 ◽  
Author(s):  
V. G. Lushchik ◽  
A. E. Yakubenko
Keyword(s):  
Boundary Layer ◽  
Supersonic Boundary Layer

scholarly journals Finite-amplitude steady waves in plane viscous shear flows

1985 ◽  
Vol 160 ◽  
pp. 281-295 ◽  
Author(s):  
F. A. Milinazzo ◽  
P. G. Saffman
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Stokes Equations ◽  
Reynolds Numbers ◽  
Finite Amplitude ◽  
Linear Instability ◽  
Navier Stokes ◽  
Unidirectional Flow ◽  
Viscous Shear ◽  
Finite Amplitude Waves

Computations of two-dimensional solutions of the Navier–Stokes equations are carried out for finite-amplitude waves on steady unidirectional flow. Several cases are considered. The numerical method employs pseudospectral techniques in the streamwise direction and finite differences on a stretched grid in the transverse direction, with matching to asymptotic solutions when unbounded. Earlier results for Poiseuille flow in a channel are re-obtained, except that attention is drawn to the dependence of the minimum Reynolds number on the physical constraint of constant flux or constant pressure gradient. Attempts to calculate waves in Couette flow by continuation in the velocity of a channel wall fail. The asymptotic suction boundary layer is shown to possess finite-amplitude waves at Reynolds numbers orders of magnitude less than the critical Reynolds number for linear instability. Waves in the Blasius boundary layer and unsteady Rayleigh profile are calculated by employing the artifice of adding a body force to cancel the spatial or temporal growth. The results are verified by comparison with perturbation analysis in the vicinity of the linear-instability critical Reynolds numbers.

Sign in / Sign up

Export Citation Format

Share Document