Back-pressure effects on unsteadiness of separation shock in a rectangular duct at Mach 3

Xiong, Bing; Fan, Xiaoqiang; Wang, Yi; Zhou, Liang; Tao, Yuan

doi:10.1016/j.actaastro.2017.09.032

Cited by 30 publications

(9 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In these studies, researchers usually use mechanical throttling of the flow to simulate combustion-driven high-backpressure. The results of these studies prove the effectiveness of the experimental method based on the mechanical throttling system, and reproduce the flow characteristics during the unstart process well [14][15][16]. These studies revealed that the downstream backpressure increase from the flow-throttling device choked the flow in the inlet-isolator.…”

Section: Introductionsupporting

confidence: 65%

“…Unstart can lead to unsteady and The downstream backpressure increases as the result of the thermal choking that is triggered by the excessive heat that is released in the combustor, which has been considered as a leading cause of unstart [4][5][6]. The rising backpressure chokes the inlet flow and forms upstream propagating disturbances as an unstart shock train system [13][14][15]. The unstart shock train system, which involves an interaction between the duct's peripheral boundary layer and the central shock wave field, usually appears in constant or nearly constant cross-sectional area supersonic/hypersonic duct flows [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

“…The rising backpressure chokes the inlet flow and forms upstream propagating disturbances as an unstart shock train system [13][14][15]. The unstart shock train system, which involves an interaction between the duct's peripheral boundary layer and the central shock wave field, usually appears in constant or nearly constant cross-sectional area supersonic/hypersonic duct flows [15][16][17]. To contain the unstart shock train system caused by the downstream pressure rise from combustion, an isolator portion of a scramjet engine is a constant-area duct located between the engine inlet and the combustor section.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

et al. 2019

View full text Add to dashboard Cite

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.

show abstract

Section: Introductionsupporting

confidence: 65%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The difference between Grid 6 and Grid 7 is not significant and the relative The coupling between the shock train motion with the pressure fluctuations may generate noise or fluctuated wall loads. 34 Turbulent combustion in the combustion chamber is characterised by a stochastic character, which give birth to stochastic oscillations of parameters. However, as the pressure fluctuations produced in the combustor propagate upstream, interactions with the shock waves in the channel generate additional disturbances.…”

Section: B Physical Setupmentioning

confidence: 99%

Effect of back-pressure forcing on shock train structures in rectangular channels

et al. 2018

View full text Add to dashboard Cite

“…According to the deflection direction of the shock train, two separation modes were summarized and compared. The influence of backpressure was further investigated, and the results showed that the oscillation frequency increased with increasing backpressure (Xiong et al, 2017b). Hunt and Gamba (2018) demonstrated that the internal structure of the shock train changes during oscillation because the oscillation frequencies of shock waves at different positions inside the shock train were different.…”

Section: Introductionmentioning

confidence: 99%

Experimental study and analysis of shock train self-excited oscillation in an isolator with background waves

Hou

Chang

Kong

et al. 2020

J. Zhejiang Univ. Sci. A

View full text Add to dashboard Cite

A study of shock train self-excited oscillation in an isolator with background waves was implemented through a wind tunnel experiment. Dynamic pressure data were captured by high-frequency pressure measurements and the flow field was recorded by the high-speed Schlieren technique. The shock train structure was mostly asymmetrical during self-excited oscillation, regardless of its oscillation mode. We found that the pressure discontinuity caused by background waves was responsible for the asymmetry. On the wall where the pressure at the leading edge of the shock train was lower, a large separation region formed and the shock train deflected toward to the other wall. The oscillation mode of the shock train was related to the change of wall pressure in the oscillation range of its leading edge. The oscillation range and oscillation intensity of the shock train leading edge were affected by the wall pressure gradient induced by background waves. When located in a negative pressure gradient region, the oscillation of the leading edge strengthened; when located in a positive pressure gradient region, the oscillation weakened. To find out the cause of self-excited oscillation, correlation and phase analyses were performed. The results indicated that the instability of the separation region induced by the leading shock was the source of perturbation that caused self-excited oscillation, regardless of the oscillation mode of the shock train.

show abstract

Back-pressure effects on unsteadiness of separation shock in a rectangular duct at Mach 3

Cited by 30 publications

References 18 publications

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

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

Effect of back-pressure forcing on shock train structures in rectangular channels

Experimental study and analysis of shock train self-excited oscillation in an isolator with background waves

Contact Info

Product

Resources

About