Modal Analysis of Receptivity Mechanisms for a Freestream Hot-Spot Perturbation on a Blunt Compression-Cone Boundary Layer

Miselis, Michael; Huang, Yuet; Zhong, Xiaolin

doi:10.2514/6.2016-3345

Cited by 11 publications

(3 citation statements)

References 25 publications

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“…When this is the case, the current LST formulation fails to predict the supersonic mode, and other methods, such as DNS or nonlinear PSE, must be used to resolve the supersonic mode. To investigate the relative contribution of each mode to the DNS disturbance, a multimode decomposition using methods and tools developed by Gaydos and Tumin [47] and Miselis et al [48] must be performed.…”

Section: A Case 1 Unsteady Direct Numerical Simulation Resultsmentioning

confidence: 99%

Significant Supersonic Modes and the Wall Temperature Effect in Hypersonic Boundary Layers

Knisely

Zhong

2019

AIAA Journal

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Note the importance of the relative sonic line y s , indicated by My s −1, where My uy − c ay where uy is the local mean flow velocity tangential to the wall, c ω∕ β 2 α 2 p is the disturbance propagation speed (with ω the circular frequency, β the spanwise wave number, and α the streamwise wave number), and ay is the local mean flow speed of sound. The disturbance propagation speed c is constant in the wall-normal direction for the entire disturbance structure at a fixed frequency and location. Between the sonic line and the wall, the disturbance is propagating downstream supersonically with respect to the mean flow velocity, resulting in the acousticlike behavior. Again, the acoustic description of the flow is only exact in very particular circumstances [6-8] but provides a qualitatively similar description of the flow in reality. Outside of the sonic line, the disturbance propagates subsonically. At the critical layer [ My c 0], ropelike structures are observed both numerically [9-11] and experimentally [12,13]. Because the disturbance travels subsonically in the freestream [ My < 1], the traditional second mode is referred to as a subsonic mode. When the phase speed of the disturbance is supersonic with respect to the mean flow in the freestream [ My > 1], the mode is known as a supersonic mode, and additional physical phenomena are encountered. A schematic similar to Fig. 1 is presented in Fig. 2 for the supersonic mode, which shows the same structures near the wall as the subsonic mode. Below the first sonic line [ My s1 −1], the disturbance propagates downstream supersonically with respect to the mean flow, and the critical layer [ My c 0] is outside of this first sonic line. However, with the supersonic mode, a second relative sonic line is included [ My s2 1], outside of which the disturbance travels upstream supersonically with respect to the mean flow. The three distinct regions (two supersonic, one subsonic) have also been described by Mack [6]. In the outer supersonic region, because there

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Section: A Case 1 Unsteady Direct Numerical Simulation Resultsmentioning

confidence: 99%

Significant Supersonic Modes and the Wall Temperature Effect in Hypersonic Boundary Layers

Knisely

Zhong

2019

AIAA Journal

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“…For example, hypersonic boundary layer receptivity under free-stream disturbance refers to the process that occurs when disturbances in the free-stream enter the boundary layer and result in the generation of perturbations in the boundary layer. Many scholars have researched hypersonic boundary layer receptivity [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ], but it is not yet fully understood because the hypersonic boundary layer receptivity is affected by many factors. These factors interact with each other, which increases the complexity of the hypersonic boundary layer receptivity.…”

Section: Introductionmentioning

confidence: 99%

“…They also reported that these three kinds of free-stream disturbances could generate unsteady perturbations in the boundary layer without considering the interaction between the free-stream disturbances or the roughness element on the wall. Miselis et al [ 11 ] combined the direct numerical simulation method and the multiple mode decomposition method to examine the hypersonic boundary layer receptivity under entropy waves in free-stream. The results of the numerical simulation were in good agreement with the experimental results.…”

Section: Introductionmentioning

confidence: 99%

Effect of a Roughness Element on the Hypersonic Boundary Layer Receptivity Due to Different Types of Free-Stream Disturbance with a Single Frequency

Shi

Wang

et al. 2019

Entropy

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The hypersonic flow field around a blunt cone was simulated using a high-order finite difference method. Fast acoustic waves, slow acoustic waves, entropy waves, and vortical waves were introduced into the free-stream to determine the influence of a free-stream with disturbances on the hypersonic flow field and boundary layer. The effect of disturbance type on the evolution of perturbations in the hypersonic boundary layer was analyzed. Fast Fourier Transform was adopted to analyze the effect of the disturbance type on the evolution of different modes in the boundary layer. A roughness element was introduced into the flow field to reveal the impact of the roughness element on hypersonic boundary layer receptivity. The results showed that a free-stream with disturbances affected the hypersonic flow field and boundary layer; acoustic waves had the greatest influence. The impact of slow acoustic waves on the flow field was mainly concentrated in the region between the shock and the boundary layer, whereas the influence of fast acoustic waves was mainly concentrated in the boundary layer. Multi-mode perturbations formed in the boundary layer were caused by the free-stream with disturbances, wherein the fundamental mode was the dominant mode of the perturbations in the boundary layer caused by fast acoustic waves, entropy waves, and vortical waves. The dominant modes of the perturbations in the boundary layer caused by slow acoustic waves were both the fundamental mode and the second harmonic mode. The roughness element changed the propagation process of different modes of perturbations in the boundary layer. In the downstream region of the roughness element, perturbations in the boundary layer caused by the slow acoustic waves had the greatest influence. The second harmonic mode in the boundary layer was significantly suppressed, and the fundamental mode became the dominant mode. The effects of fast acoustic waves and entropy waves on the boundary layer receptivity were similar, except the amplitude of the perturbations in the boundary layer caused by the fast acoustic waves was larger.

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Impact of Vibrational Nonequilibrium on the Supersonic Mode in Hypersonic Boundary Layers

Knisely

Zhong

2020

AIAA Journal

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Modal Analysis of Receptivity Mechanisms for a Freestream Hot-Spot Perturbation on a Blunt Compression-Cone Boundary Layer

Cited by 11 publications

References 25 publications

Significant Supersonic Modes and the Wall Temperature Effect in Hypersonic Boundary Layers

Significant Supersonic Modes and the Wall Temperature Effect in Hypersonic Boundary Layers

Effect of a Roughness Element on the Hypersonic Boundary Layer Receptivity Due to Different Types of Free-Stream Disturbance with a Single Frequency

Impact of Vibrational Nonequilibrium on the Supersonic Mode in Hypersonic Boundary Layers

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