Postponing the Onset and Alleviating the Load of Transonic Buffet by Using Steady and Periodic Tangential Slot Blowing

Dang, Huixue; Zhao, Jianyou; Yang, Zhichun; Dang, Huibo

doi:10.3390/app9194132

Cited by 3 publications

(5 citation statements)

References 53 publications

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“…where LHS and RHS represent the left and right terms of Equation (8), respectively; R i is the correlation between the standard Reynolds stress tensor and turbulent heat flux; C p is the pressure coefficient; T is the temperature; and * denotes averaging * .…”

Section: Nonlinear Acoustic Equations and Their Numerical Solutionsmentioning

confidence: 99%

“…These vibrations not only affect the overall comfort of the flight but also create psychological pressure on both the pilot and passengers. In severe cases, they can pose safety risks such as structural fatigue damage, seal failure, and even casualties [6][7][8]. When such vibrations occur under fluid-induced conditions, it is crucial for the ground crew to identify and rectify the source of the fault promptly.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Study on the Unusual Vibration Load Characteristics and Mechanisms of the Front Landing Gear Compartment

Dang,

Xu,

Wang

et al. 2023

Aerospace

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Civilian aircraft can experience noticeable vibrations in the cockpit and cabin due to mechanical faults during flight. To address this issue, a hybrid approach was utilized to investigate fluid-induced vibration load characteristics in the front landing gear compartment under different hatch opening angles. The results reveal that the root mean square (RMS) of cumulative pressure loads on both small and large hatches under different opening angles is largest at a 15°. For all the simulated cases (0°, 5°, 10°, 15°, 20°), the power spectral density (PSD) results of the chosen monitoring points on the inner wall of the large hatch exhibit broadband frequency characteristics, and the peak PSD values for the chosen monitoring points on the outer wall of the small hatch exhibit a significant concentration of energy at approximately 75 Hz. The peak PSD values for the selected monitoring points on the inner wall of the small hatch demonstrate a more uniform distribution of energy. Utilizing the iso-surface of Q-criterion, spatial streamlines, and streamlines at different cross-sections to analyze flow characteristics, the study investigates the fluctuating load mechanisms of the compartments. The results indicate that unsteady loads stem from the blunt edges of the hatches, which induce unsteady flow and spanwise flow. Geometric gaps between different locations cause flow separation, and the flows inside the compartment exhibit characteristics similar to those of a clean cavity. Furthermore, the mutual interference can be described using circulating flow and spanwise flow, resulting in flow unsteadiness. The flow separation zones enlarge and vortex intensity increases with the increase of the hatch opening angle from 0° to 15°; then, their values decrease as the hatch opening angle increases from 15° to 20°. These variations explain the maximum RMS of cumulative pressure loads at 15°.

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Section: Nonlinear Acoustic Equations and Their Numerical Solutionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Numerical Study on the Unusual Vibration Load Characteristics and Mechanisms of the Front Landing Gear Compartment

Dang,

Xu,

Wang

et al. 2023

Aerospace

View full text Add to dashboard Cite

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“…Since transport aircraft usually travel at transonic speeds, wave drag generated by transonic shocks on the wing surfaces also provides a significant contribution to overall aircraft drag. Furthermore, the phenomenon of buffet can occur which can lead to structural vibrations and thus limit the flight envelop [6][7][8]. For a review of transonic shock buffet the reader is referred to Giannelis et al [9].…”

Section: Introductionmentioning

confidence: 99%

“…The goals of shock control are to implement a device which reduces the shock strength and consequently wave drag and/or to delay the buffet onset and thus to reduce emissions, extend the flight envelop and/or reduce flow induced vibrations. While the drag reduction potential of SCBs has been investigated over almost the past three decades [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25], buffet control by SCBs has been investigated less extensively [6][7][8][9][26][27][28][29]. For detailed research on buffet control via SCBs the reader is referred to Mayer [6] and Mayer et al [7].…”

Section: Introductionmentioning

confidence: 99%

Review of Adaptive Shock Control Systems

et al. 2021

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Drag reduction plays a major role in future aircraft design in order to lower emissions in aviation. In transonic flight, the transonic shock induces wave drag and thus increases the overall aircraft drag and hence emissions. In the past decades, shock control has been investigated intensively from an aerodynamic point of view and has proven its efficacy in terms of reducing wave drag. Furthermore, a number of concepts for shock control bumps (SCBs) that can adapt their position and height have been introduced. The implementation of adaptive SCBs requires a trade-off between aerodynamic benefits, system complexity and overall robustness. The challenge is to find a system with low complexity which still generates sufficient aerodynamic improvement to attain an overall system benefit. The objectives of this paper are to summarize adaptive concepts for shock control, and to evaluate and compare them in terms of their advantages and challenges of their system integrity so as to offer a basis for robust comparisons. The investigated concepts include different actuation systems as conventional spoiler actuators, shape memory alloys (SMAs) or pressurized elements. Near-term applications are seen for spoiler actuator concepts while highest controllability is identified for concepts several with smaller actuators such as SMAs.

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“…Such a model can be used to improve the aeroacoustic performances of turbofans by active flow control. In another one [7], the effects of both steady and periodic tangential slot blowing are investigated with the aim to delay buffet onset and alleviate the buffet load. The results show that steady tangential blowing on the airfoil upper surface can postpone the buffet onset margin and evidently increase the lift coefficient at incidence angles near and above the buffet onset case of the clean airfoil.…”

Section: Introductionmentioning

confidence: 99%

Aeroacustic and Vibroacoustic Advancement in Aerospace and Automotive Systems

2020

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This Special Issue highlights the latest enhancements in the abatement of noise and vibrations of aerospace and automotive systems. The reduction of acoustic emissions and the improvement of cabin interior comfort are on the path of all major transportation industries, having a direct impact on customer satisfaction and, consequently, the commercial success of new products. Topics covered in this Special Issue deal with computational, instrumentation and data analysis of noise and vibrations of fixed wing aircrafts, satellites, spacecrafts, automotives and trains, ranging from aerodynamically generated noise to engine noise, sound absorption, cabin acoustic treatments, duct acoustics and vibroacoustic properties of materials. The focus of this Special Issue is also related to industrial aspects, e.g.,: numerical and experimental studies have been performed for an existing and commercialized engine to enable design improvements aimed at reducing noise and vibrations; moreover, an optimization is provided for the design of low vibroacoustic volute centrifugal compressors and fans whose fluids should be strictly kept in the system without any leakage. Existing procedures and algorithms useful to reach the abovementioned objectives in the most efficient way are illustrated in the collected papers.

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Postponing the Onset and Alleviating the Load of Transonic Buffet by Using Steady and Periodic Tangential Slot Blowing

Cited by 3 publications

References 53 publications

Numerical Study on the Unusual Vibration Load Characteristics and Mechanisms of the Front Landing Gear Compartment

Numerical Study on the Unusual Vibration Load Characteristics and Mechanisms of the Front Landing Gear Compartment

Review of Adaptive Shock Control Systems

Aeroacustic and Vibroacoustic Advancement in Aerospace and Automotive Systems

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