Recent research progress on unstart mechanism, detection and control of hypersonic inlet

Chang, Juntao; Li, Nan; Xu, Kejing; Bao, Wen; Yu, Daren

doi:10.1016/j.paerosci.2016.12.001

Cited by 195 publications

(47 citation statements)

References 118 publications

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“…Figure 8 shows the standard deviation distribution inside the inlet. From Figure 8 we can see that: (1) At nearly x/L = 0.07 and x/L = 0.75, the standard deviation σ approaches to zero. It means that the transient pressure does not vary with time at these positions.…”

Section: Analysis Based On Numerical Results and Podmentioning

confidence: 90%

“…The inlet buzz is an extremely unstable flow status observed in various supersonic and hypersonic air-breathing systems [1]. It usually occurs when the inlet operates in a subcritical flow regime and the entering mass flow drops under a certain threshold [2][3][4].…”

Section: Introductionmentioning

confidence: 99%

“…Since the inlet buzz was first observed by Oswatitsch [7] in the experimental study of an asymmetrically configured missile inlet system, numerous remarkable experimental investigations have been carried out in the past decades. Thus, numerous cognitions concerning the mechanism of the inlet buzz have been obtained: (1) In a general sense, the inlet buzz could be classified into two types, namely the little buzz and the big buzz [3,4,[8][9][10][11][12]. The former one is basically characterized by the flow 2 of 23 oscillation with a small amplitude, while the latter features large-scale shock motion accompanied by enormous pressure oscillation and flow choke.…”

Section: Introductionmentioning

confidence: 99%

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Spatiotemporal Characterization and Suppression Mechanism of Supersonic Inlet Buzz with Proper Orthogonal Decomposition Method

Luo

Wei

et al. 2020

Energies

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The buzz phenomenon of a typical supersonic inlet is analyzed using the unsteady Reynolds Average Navier-Stokes (RANS) simulation and proper orthogonal decomposition (POD) method. The dominant flow patterns and characteristics of the buzzed flow are obtained by decoupling the computed pressure field into spatial and temporal sub-parts based on the POD method. The supersonic inlet buzz phenomenon could be approximated as a product of decoupled temporal and spatial terms, and the one-dimensional (1D) mathematical model is therefore proposed. The standard deviations of the unsteady pressure fields from both the numerical simulation and the model prediction are compared. The limited discrepancy can be observed, and the good agreement validates the credibility of the proposed 1D model. The numerical simulation and the 1D model prediction are presented to explore the unsteady-jet control with a small perturbation. The results of the 1D model and the numerical simulation achieve good agreements with each other in terms of the overall trend. Finally, POD modal energy is employed to analyze the buzz suppression mechanism. When the jet frequency is identical to the dominant frequency of the buzz and the jet phase is opposite to the oscillation phase of the captured mass flow, the buzz suppression could be more efficient. The buzz suppression mechanism could be explained in two aspects. For one thing, the complex flow structure is suppressed and the first average modal energy in the inlet is increased. For another, the energy redistribution among each POD mode is achieved and the flow stability is gradually enhanced.

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Section: Analysis Based On Numerical Results and Podmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Spatiotemporal Characterization and Suppression Mechanism of Supersonic Inlet Buzz with Proper Orthogonal Decomposition Method

Luo

Wei

et al. 2020

Energies

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“…For a highly efficient hypersonic airbreathing propulsion system, the inlet should provide high-performance compression with minimum aerodynamic losses produced by shock waves and fluid viscosity. Meanwhile, the inlet should be operated in a started mode [1][2][3][4][5][6][7][8][9][10]. From the view of flow structure [6], the hypersonic inlet unstart is defined as the disgorging of the shock train system in the scramjet engine inlet and isolator.…”

Section: Introductionmentioning

confidence: 99%

Correlation Analysis of Separation Shock Oscillation and Wall Pressure Fluctuation in Unstarted Hypersonic Inlet Flow

et al. 2019

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The flow field in a hypersonic inlet model at a design point of M = 6 has been studied experimentally. The focus of the current study is to present the time-resolved flow characteristics of separation shock around the cowl and the correlation between the separation shock oscillation induced by the unstart flow and the wall pressure fluctuation when the inlet is in a state of unstart. High-speed Schlieren flow visualization is used to capture the transient shock structure. High-frequency pressure transducers are installed on the wall around both the cowl and isolator areas to detect the dynamic pressure distribution. A schlieren image quantization method based on gray level detection and calculation is developed to analyze the time-resolved spatial structure of separation shock. Results indicate that the induced separation shock oscillation and the wall pressure fluctuation are closely connected, and they show the same frequency variation characteristics. The unsteady flow pattern of the “little buzz” and “big buzz” modes are clarified based on time-resolved Schlieren images of separation shock. Furthermore, the appropriate location of the pressure transducers is determined on the basis of the combined analysis of fluctuating wall-pressure and oscillating separation shock data.

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“…Subsequently, schlieren flow visualization was employed to investigate the cowl/ramp shock interactions by Mahapatra and Jagadeesh. 5,6 They considered that the main reason for the inlet unstart pattern was the forebody shock/cowl a) Electronic mail: york tao@126.com b) Electronic mail: wdliu@nudt.edu.cn c) Electronic mail: xiaoqiangfan@hotmail.com d) Electronic mail: zhaoyilong2007@126.com shock interaction, so did Jiao et al 7,8 and Tao et al 9 Moreover, Jiao et al 7,8 and Chang et al 10 defined this phenomenon as "local unstart." Fan and Tao 11 displayed two different experimental configurations under the uniform working conditions, shown in Fig.…”

mentioning

confidence: 99%

Structural characteristics of the shock-induced boundary layer separation extended to the leading edge

et al. 2017

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For a better understanding of the local unstart of supersonic/hypersonic inlet, a series of experiments has been conducted to investigate the shock-induced boundary layer separation extended to the leading edge. Using the nanoparticle-based planar laser scattering, we recorded the fine structures of these interactions under different conditions and paid more attention to their structural characteristics. According to their features, these interactions could be divided into four types. Specifically, Type A wave pattern is similar to the classic shock wave/turbulent boundary layer interaction, and Type B wave configuration consists of an overall Mach reflection above the large scale separation bubble. Due to the gradual decrease in the size of the separation bubble, the separation bubble was replaced by several vortices (Type C wave pattern). Besides, for Type D wave configuration which exists in the local unstart inlet, there appears to be some flow spillage around the leading edge.

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Recent research progress on unstart mechanism, detection and control of hypersonic inlet

Cited by 195 publications

References 118 publications

Spatiotemporal Characterization and Suppression Mechanism of Supersonic Inlet Buzz with Proper Orthogonal Decomposition Method

Spatiotemporal Characterization and Suppression Mechanism of Supersonic Inlet Buzz with Proper Orthogonal Decomposition Method

Correlation Analysis of Separation Shock Oscillation and Wall Pressure Fluctuation in Unstarted Hypersonic Inlet Flow

Structural characteristics of the shock-induced boundary layer separation extended to the leading edge

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