Experimental investigation of the pulsing flow field around four types of spiked-blunt body at Mach 2.2

Guan, Ruiqing; Qin, Qihao; Wang, Yifan; Huang, Shuai

doi:10.1016/j.ast.2023.108129

Cited by 6 publications

(2 citation statements)

References 35 publications

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“…This aftershock also exhibits an axisymmetric distribution, but it is stronger in the central area of the cylindrical blunt body and weaker at the shoulders. This observation is similar to the spatial structure observed in the suppressed pulsation mode as observed in a previous study [52], where the aftershock entirely covers the windward surface of the cylindrical blunt body. The primary frequency of 3.3 kHz arises from the low-amplitude pulsations of the aftershock.…”

Section: Novel Energy Sorting Criterionsupporting

confidence: 90%

Experimental Investigation of the Shock-Related Unsteadiness around a Spiked-Blunt Body Based on a Novel DMD Energy Sorting Criterion

Wang,

Xu,

Qin

et al. 2024

Aerospace

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In this study, we propose a novel dynamic mode decomposition (DMD) energy sorting criterion that works in conjunction with the conventional DMD amplitude-frequency sorting criterion on the high-dimensional schlieren dataset of the unsteady flow of a spiked-blunt body at Ma = 2.2. The study commences by conducting a comparative analysis of the eigenvalues, temporal coefficients, and spatial structures derived from the three sorting criteria. Then, the proper orthogonal decomposition (POD) and dynamic pressure signals are utilised as supplementary resources to explore their effectiveness in capturing spectral characteristics and spatial structures. The study concludes by summarising the characteristics and potential applications of DMD associated with each sorting criterion, as well as revealing the predominant flow features of the unsteady flow field around the spiked-blunt body at supersonic speeds. Results indicate that DMD using the energy sorting criterion outperforms the amplitude and frequency sorting criteria in identifying the primary structures of unsteady pulsations in the flow field, which proves its superiority in handling an experimental dataset of unsteady flow fields. Moreover, the unsteady pulsations in the flow field around the spiked-blunt body under supersonic inflow conditions are observed to exhibit multi-frequency coupling, with the primary frequency of 3.3 kHz originating from the periodic motion of the aftershock.

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Section: Novel Energy Sorting Criterionsupporting

confidence: 90%

Experimental Investigation of the Shock-Related Unsteadiness around a Spiked-Blunt Body Based on a Novel DMD Energy Sorting Criterion

Wang,

Xu,

Qin

et al. 2024

Aerospace

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“…When the input power is relatively small, the system could not start, which shows dead zone characteristics in both positive and negative directions. The hydraulic system shows a discontinuous non-linear characteristic during finer increments of the manipulation and suffers from mechanical friction and disturbance [19][20][21]. The hydraulic system is driven by a servo system.…”

Section: Mechanism Analyzing Of Centrosome Systemmentioning

confidence: 99%

Precision positioning control of wind tunnel centrosome

Liu,

Yuan,

Mao

2023

IET Control Theory & Appl

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The centrosome plays a crucial role in regulating the flow field of a continuous wind tunnel, and its positioning precision directly impacts the control accuracy of the Mach number. A high‐precision positioning control algorithm for the wind tunnel centrosome is proposed based on a model predictive control framework. Since that the centrosome is a typical non‐linear system with a Hammerstein structure comprising an input backlash and a linear dynamic block in series, a parameterized least‐squares identification method is constructed based on an adaptive forgetting factor strategy and a centrosome position prediction model with input backlash is established. To counteract the weakening effect of the backlash non‐linear block on the control signal, a compensator is constructed to compensate for the non‐linear input block. Considering that the input undetectable disturbance signal in the actuator may lead to unpredictable responses, an intermediate state observer is designed and the stable convergence of the observer algorithm is also proved. Finally, the closed‐loop stability of the proposed control algorithm is analyzed by constructing a Lyapunov function. Experimental testing verifies the superiority and applicability of the proposed algorithm.

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Experimental investigation of flow unsteadiness over four types of spiked-blunt body at Mach 2.2

Guan

Qin

Wang

et al. 2023

Aerospace Science and Technology

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Experimental investigation of the pulsing flow field around four types of spiked-blunt body at Mach 2.2

Cited by 6 publications

References 35 publications

Experimental Investigation of the Shock-Related Unsteadiness around a Spiked-Blunt Body Based on a Novel DMD Energy Sorting Criterion

Experimental Investigation of the Shock-Related Unsteadiness around a Spiked-Blunt Body Based on a Novel DMD Energy Sorting Criterion

Precision positioning control of wind tunnel centrosome

Experimental investigation of flow unsteadiness over four types of spiked-blunt body at Mach 2.2

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