Spatially developing DNS of second-mode instability wave generated in a supersonic boundary layer at Mach number 4.5

2000 ◽  
Vol 2000 (0) ◽  
pp. 10
Author(s):  
Kenshi YAMASHITA ◽  
Hiroshi MAEKAWA
Keyword(s):  
Boundary Layer ◽  
Mach Number ◽  
Supersonic Boundary Layer ◽  
Instability Wave ◽  
Mode Instability ◽  
Second Mode

Nonlinear evolution of a pair of oblique instability waves in a supersonic boundary layer

1995 ◽  
Vol 282 ◽  
pp. 339-371 ◽  
Author(s):  
S. J. Leib ◽  
Sang Soo Lee
Keyword(s):  
Boundary Layer ◽  
Mach Number ◽  
Nonlinear Evolution ◽  
Supersonic Boundary Layer ◽  
Inviscid Limit ◽  
Instability Wave ◽  
Neutral Stability ◽  
Mean Flow ◽  
Number Range ◽  
Instability Waves

We study the nonlinear evolution of a pair of oblique instability waves in a supersonic boundary layer over a flat plate in the nonlinear non-equilibrium viscous critical layer regime. The instability wave amplitude is governed by the same integro-differential equation as that derived by Goldstein & Choi (1989) in the inviscid limit and by Wu, Lee & Cowley (1993) with viscous effects included, but the coefficient appearing in this equation depends on the mean flow and linear neutral stability solution of the supersonic boundary layer. This coefficient is evaluated numerically for the Mach number range over which the (inviscid) first mode is the dominant instability. Numerical solutions to the amplitude equation using these values of the coefficient are obtained. It is found that, for insulated and cooled wall conditions and angles corresponding to the most rapidly growing waves, the amplitude ends in a singularity at a finite downstream position over the entire Mach number range regardless of the size of the viscous parameter. The explosive growth of the instability waves provides a mechanism by which the boundary layer can break down. A new feature of the compressible problem is the nonlinear generation of a spanwise-dependent mean distortion of the temperature along with that of the velocity found in the incompressible case.

Evolution of nonlinear processes in a hypersonic boundary layer on a sharp cone

2008 ◽  
Vol 611 ◽  
pp. 427-442 ◽  
Author(s):  
D. BOUNTIN ◽  
A. SHIPLYUK ◽  
A. MASLOV
Keyword(s):  
Boundary Layer ◽  
Mach Number ◽  
Basic Mechanism ◽  
Hypersonic Boundary Layer ◽  
Nonlinear Interactions ◽  
Nonlinear Processes ◽  
Voltage Fluctuation ◽  
Second Mode ◽  
Sharp Cone ◽  
Second Mode Of Disturbances

Nonlinear processes in a hypersonic boundary layer on a sharp cone are considered using the bicoherence method. The experiments are performed for a Mach number M∞ = 5.95 with introduction of artificial wave packets at the frequency of the second mode. It is shown that the basic mechanism of nonlinear interaction at the location of the maximum r.m.s. voltage fluctuation is the subharmonic resonance; all nonlinear interactions in the maximum r.m.s. voltage fluctuation layer are related to the second mode of disturbances; nonlinear processes above and below that layer are much more intense than those in it. The effect of artificial disturbances on nonlinear interactions in the boundary layer is shown to be insignificant.

Example of Second-Mode Instability Dominance at a Mach Number of 5.2

AIAA Journal ◽  
1992 ◽  
Vol 30 (12) ◽  
pp. 2974-2976 ◽  
Author(s):  
Kenneth F. Stetson ◽  
Roger L. Kimmel
Keyword(s):  
Mach Number ◽  
Mode Instability ◽  
Second Mode

scholarly journals Experimental Study of the Weak Shock Wave Action on the Boundary Layer of a Plate at the Mach Number 2.5

2019 ◽  
Vol 14 (2) ◽  
pp. 46-55 ◽  
Author(s):  
V. L. Kocharin ◽  
A. A. Yatskikh ◽  
A. D. Kosinov ◽  
Yu. G. Yermolaev ◽  
N. V. Semionov
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Experimental Study ◽  
Mach Number ◽  
Side Wall ◽  
Leading Edge ◽  
Weak Shock ◽  
Supersonic Boundary Layer ◽  
Weak Shock Wave ◽  
Frequency Spectra

Experimental study of the effect of a weak shock wave from the protuberance of two-dimensional roughness installed on the side wall of the test section of the wind tunnel on the supersonic boundary layer of the blunted flat plate at the Mach number 2.5 was carried out. The measurements were performed by a constant temperature hot-wire anemometer in the region of stream wise vortices generated by the shock wave from the protuberance during interaction with the flow in the vicinity of the leading edge of the model. The spectral and statistical analyses of the measured disturbances in the boundary layer were carried out. The amplitude-frequency spectra of mass flow pulsations and statistical diagrams of the measured disturbances in the supersonic part of the boundary layer were obtained.

scholarly journals Development of second-mode instability in a Mach 6 flat plate boundary layer with two-dimensional roughness

2015 ◽  
Vol 27 (6) ◽  
pp. 064105 ◽  
Author(s):  
Qing Tang ◽  
Yiding Zhu ◽  
Xi Chen ◽  
Cunbiao Lee
Keyword(s):  
Boundary Layer ◽  
Flat Plate ◽  
Plate Boundary ◽  
Two Dimensional ◽  
Mode Instability ◽  
Second Mode ◽  
Flat Plate Boundary Layer

Experimental study of second-mode instability growth and breakdown in a hypersonic boundary layer using high-speed schlieren visualization

2016 ◽  
Vol 797 ◽  
pp. 471-503 ◽  
Author(s):  
S. J. Laurence ◽  
A. Wagner ◽  
K. Hannemann
Keyword(s):  
Boundary Layer ◽  
High Speed ◽  
Porous Ceramic ◽  
Propagation Speed ◽  
Mode Instability ◽  
Instability Waves ◽  
Local Maxima ◽  
High Enthalpy ◽  
Reflected Shock ◽  
Second Mode

Visualization experiments are performed to investigate the development of instability waves within the boundary layer on a slender cone under high Mach number conditions. The experimental facility is a reflected-shock wind tunnel, allowing both low (Mach-8 flight equivalent) and high-enthalpy conditions to be simulated. Second-mode instability waves are visualized using a high-speed schlieren set-up, with pulse bursting of the light source allowing the propagation speed of the wavepackets to be unambiguously resolved. This, in combination with wavelength information derived from the images, enables the calculation of the disturbance frequencies. At the lower-enthalpy conditions, we concentrate on the late laminar and transitional regions of the flow. General characteristics are revealed through time-resolved and ensemble-averaged spectra on both smooth and porous ceramic surfaces of the cone. Analysis of the development of individual wavepackets is then performed. It is found that the wavepacket structures evolve from a ‘rope-like’ appearance to become more interwoven as the disturbance nears breakdown. The wall-normal disturbance distributions of both the fundamental and first harmonic, which initially have local maxima at the wall and near $y/{\it\delta}=0.7$–0.75, exhibit an increase in signal energy close to the boundary-layer edge during this evolution. The structure angle of the disturbances also undergoes subtle changes as the wavepacket develops prior to breakdown. Experiments are also performed at high-enthalpy ($h_{0}\approx 12~\text{MJ}~\text{kg}^{-1}$) conditions in the laminar regime, and the visualization technique is shown to be capable of resolving wavepacket propagation speeds and frequencies at such conditions. The visualizations reveal a somewhat different wall-normal distribution to the low-enthalpy case, with the disturbance energy concentrated much more towards the wall. This is attributed to the highly cooled nature of the wall at high enthalpy.

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