Article
Mechanics
A. D'Aguanno, F. F. J. Schrijer, B. W. van Oudheusden
Summary: This experimental study investigates the role of upstream traveling waves in transonic buffet using BOS technique and particle image velocimetry. The experiments focus on the spanwise organization of the buffet phenomenon and revealed that the upstream traveling pressure waves propagate at a non-zero orientation. The analysis confirms the UTWs behave as acoustic waves, traveling at the speed of sound relative to the flow, and hints at modulation of their strength during the buffet cycle in support of the feedback-mechanism description of transonic buffet.
Article
Mechanics
Jing Wang, Hairun Xie, Miao Zhang, Hui Xu
Summary: In this paper, a Physics-Assisted Variational Autoencoder is proposed to identify dominant features of transonic buffet, which combines unsupervised reduced-order modeling with additional physical information embedded via a buffet classifier. Statistical results reveal that the buffet state can be determined exactly with just one latent space when a proper weight of classifier is chosen. Based on this identification, the displacement thickness at 80% chordwise location is proposed as a metric for buffet prediction, achieving an accuracy of 98.5% in buffet state classification.
Article
Engineering, Aerospace
Feng Deng, Shenghua Zhang, Ning Qin
Summary: In this paper, a closed-loop control using an active shock control bump (SCB) has been proposed to suppress the buffet on a supercritical airfoil flying at transonic speeds. The control law is designed based on the lift coefficient as the feedback signal and the bump height as the control variable. Numerical simulations show that the buffet can be effectively suppressed by optimizing the control law parameters, namely the gain and the delay time. The active SCB has advantages over the reference active trailing edge flap, including less sensitivity to control law parameters and a shorter response time.
Article
Engineering, Mechanical
Kai Ren, Chuanqiang Gao, Fangqi Zhou, Weiwei Zhang
Summary: The smart skin system effectively eliminates the fluctuating load of transonic buffet by measuring the airfoil lift coefficient and using data-driven, model-free adaptive control, without affecting the aerodynamic performance in the non-buffeting state.
Article
Engineering, Aerospace
Davide Di Pasquale, Simon Prince
Summary: As modern transport aircraft cruise at transonic speeds, the challenge of shock buffet alleviation becomes crucial for civil transport research. This study investigates the use of sub-boundary layer scale period roughness to act as a virtual shock bump and enhance the buffet margin. The experimental results showed that such periodic roughness can bifurcate the shock wave and delay shock-induced separations, offering potential for extending the safe flight envelope.
Article
Engineering, Aerospace
Andrea Sansica, Jean-Christophe Loiseau, Masashi Kanamori, Atsushi Hashimoto, Jean-Christophe Robinet
Summary: This study simulated and analyzed the shock wave dynamics on a two-dimensional airfoil at transonic buffet conditions, and utilized the SINDy technique to extract a parameterized simplified description. By using this simplified model, real-time estimation of the whole flowfield from the lift coefficient can be achieved.
Article
Engineering, Aerospace
Alessandro Accorinti, Tim Baur, Sven Scharnowski, Christian J. Kaehler
Summary: This study experimentally investigated the self-sustained shock wave oscillations on a supercritical airfoil under various aerodynamic conditions. The results showed that the inversion of shock motion is a necessary but not sufficient condition for buffet onset. The buffet amplitude was smaller, and buffet onset occurred at higher angles of attack compared to previous literature. The analysis also revealed a sensitivity of buffet features to numerical and experimental parameters, while being virtually insensitive to boundary-layer suction and gap flow.
Article
Engineering, Aerospace
Christopher Julian Schauerte, Anne-Marie Schreyer
Summary: This experimental investigation analyzes the development and decay of transonic buffet, as well as the flow field and shock motion on the supercritical airfoil OAT15A. The database includes high-speed schlieren sequences that provide insights into the behavior of oscillatory shock motion. The study extracts multiple temporal and spectral properties to distinguish different phases of buffet. Particle-image velocimetry measurements offer a detailed understanding of the turbulence structure and behavior during a fully established buffet cycle.
Article
Nanoscience & Nanotechnology
Bing Han, Min Xu, Guoguang Chen, Tianxing Cai, Wenhu Wang, Shixi Guan
Summary: This study numerically investigates the transonic buffet phenomenon over a prescribed-pitching airfoil using a validated simulation approach. The results show that the lift fluctuations in the pitching case are larger than those in the fixed case, and the presence of shock wave interactions and boundary separation contribute to higher pressure and velocity fluctuation levels. The unsteady flow in the pitching case exhibits a more disordered pattern compared to the periodic shedding in the wake of the fixed case. The analysis also reveals strong interactions between the shock oscillations and Karman vortex structure.
Article
Engineering, Aerospace
Pradeep Moise, Markus Zauner, Neil D. Sandham, Sebastian Timme, Wei He
Summary: Transonic buffet refers to self-sustained flow unsteadiness caused by shock-wave/boundary-layer interaction over airfoils and wings. It is classified into laminar or turbulent types based on the state of the boundary layer. In this study, large-eddy simulations are used to directly compare the two types and analyze their dynamic features. The results show that the essential dynamic features remain the same for both types, suggesting a common fundamental mechanism.
Article
Engineering, Aerospace
Ziyang Liu, Renkun Han, Miao Zhang, Yang Zhang, Hao Zhou, Gang Wang, Gang Chen
Summary: This article introduces the method of using reduced-order model technology based on deep learning to study the transonic buffet flow field. An enhanced hybrid deep neural network is constructed to predict the complex flow characteristics of buffet flow by mining the spatial-temporal features from large-scale flow field data. The predicted result is consistent with numerical simulation and has good generalization ability.
AEROSPACE SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Aerospace
Tim Korthaeuer, Alessandro Accorinti, Sven Scharnowski, Christian J. Kaehler
Summary: The transonic flow around an elastically suspended supercritical airfoil was experimentally studied to understand the buffet boundary dependencies and self-excited fluid-structure interaction. Observations showed that the shock position was affected by Mach number and pitch eigenfrequency. The fluid-structure interaction exhibited characteristics of structural frequency lock-in and mode veering.
Article
Mechanics
Enrico Degregori, Jae Wook Kim
Summary: The research demonstrates that wavy leading edge airfoils are more effective than straight leading edge ones, with the smallest amplitude airfoil performing the best. Unsteadiness in flow plays a crucial role in the performance of airfoils in transonic flows at moderate and high angles of attack.
Article
Engineering, Mechanical
A. D'Aguanno, F. F. J. Schrijer, B. W. van Oudheusden
Summary: The study investigated the transonic buffet behavior of the supercritical airfoil OAT15A through experimental and numerical methods, revealing the main modes connected with buffet. The first three most energetic modes captured a majority of the fluctuating kinetic energy and displayed distinct characteristics from the buffet behavior.
EXPERIMENTS IN FLUIDS
(2021)
Article
Multidisciplinary Sciences
Asad Islam, Hongwei Ma
Summary: This paper investigates the impact of probes on the performance of a transonic axial speed compressor, revealing that probe parameters have a significant influence on compressor output and change the performance trend from the choke to the stall.
Article
Energy & Fuels
Yaozhong Han, Weimin Cheng, Hao Liu, Gang Wang, Yanwei Hu
Summary: This study explored the distribution law of natural wind pressure in mines, identified the sensitive branches, and designed a control scheme to mitigate the adverse impacts of natural wind pressure on Wudong Coal Mine. The implementation of the scheme effectively ensured the safe and efficient production of the mine.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2023)
Article
Energy & Fuels
Jian Chen, Weimin Cheng, Gang Wang, Haomiao Li
Summary: By simulating the propagation process of ultrasonic waves in a water migration porous medium, the study reveals the law of ultrasonic wave propagation and the impact of water migration within it.
Article
Energy & Fuels
Jian Chen, Weimin Cheng, Gang Wang, Haomiao Li
Summary: This study utilized the method of cross-scale CT image joint analysis to reconstruct and verify composite models of different specimens, revealing further insights into the water migration process during water injection.
Article
Energy & Fuels
Zhenyang Wang, Yuanping Cheng, Gang Wang, Guanhua Ni, Liang Wang
Summary: This study utilized low pressure argon adsorption and low pressure nitrogen adsorption to analyze the pore parameters of coal with different metamorphism. The results showed that LP-ArGA has advantages in pore analysis and can accurately characterize the pore characteristics of coal.
Article
Energy & Fuels
Qiming Huang, Bing Wu, Yu Liu, Zhiguo Guo, Gang Wang, Lulu Sun
Summary: The study found that there was no significant chemical reaction between the coal component and polyacrylamide. Due to the porosity of the polyacrylamide coating adhered onto the surface of the pore, it has a significant sorption capacity for methane. However, as the amount of residue entering the pores increases, the porous structure of the polyacrylamide coating becomes denser, leading to a decrease in the overall sorption capacity of the "coal-polyacrylamide" system.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Construction & Building Technology
Xuezhen Wu, Hanfang Zheng, Gang Wang, Yuanjin Zhou, Zhenchang Guan
Summary: The joint planes in fractured rock mass have a significant influence on the deformation and failure mode of engineering rock mass. The effect of joint roughness and infill thickness on the shear characteristics of joints was studied through numerical simulation tests. The results showed that rock bolts improved the shear strength of infilled rock joints, increased the number of micro-cracks, and made the dilatation more obvious. The shear stress and normal displacement of unbolted or bolted infilled rock joints increased with increasing joint roughness and decreasing infill thickness.
ADVANCES IN CIVIL ENGINEERING
(2022)
Article
Mining & Mineral Processing
Gang Wang, Yanqing Li, Enmao Wang, Qiming Huang, Shibin Wang, Huaixing Li
Summary: This study investigates the influence of nanofluids on the wettability of coal surface. The experiments show that composite nanofluids can enhance the wettability of coal, and the effects are related to the metamorphic degree and particle size of coal.
INTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY
(2022)
Article
Energy & Fuels
Wei Wang, Gang Wang, Wei Zhao, Liang Wang, Zhongkai Feng, Ran Cui, Feng Du
Summary: With the increasing demand for geo-energy, the safe and efficient exploitation of deep coal resources has become increasingly important. A new permeability-enhanced method called hydraulic punching cavitation is proposed to increase the exposed area of coal bulk, release the geo-stress, and improve the coal permeability. The study shows that hydraulic punching cavitation achieves a more extensive plastic zone range and a more notable pressure relief effect than perforation cavitation.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Energy & Fuels
Shuang Ju, Qiming Huang, Gang Wang, Jian Qiao, Shibin Wang, Cunli Qin
Summary: This study investigated the synergistic stabilization mechanism of SiO2 nanoparticles and SDS during foam fracturing. The results showed that an appropriate concentration of SDS can enhance the adsorption of SiO2 nanoparticles at the gas-liquid interface, thereby improving foam stability.
Article
Energy & Fuels
Yueguo Li, Haijiao Fu, Detian Yan, Xianbo Su, Xiaoming Wang, Weizhong Zhao, Hu Wang, Gang Wang
Summary: This study reveals the significant enhancement of gas production capacity of microorganisms in deep coalbed water with high TDS content, and analyzes the changes in microbial community structure and gene function. Through these investigations, the methane-producing process of microorganisms in highTDS coalbed water is recreated.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Gang Wang, Yuanhao Liu, Qiming Huang, Enmao Wang, Ning Liu
Summary: The surface roughness of coal fractures hinders the seepage effect of coal seam water injection. Increasing the injection pressure and fracture aperture can reduce this influence.
Article
Chemistry, Multidisciplinary
Shibin Wang, Gang Wang, Jiuyuan Fan, Yuanhao Liu, Shuang Ju, Cunli Qin
Summary: This study investigates the gas emission in the working face during the horizontal sublevel mining of steeply inclined and ultrathick coal seams. The results show that the pressure relief area in the lower section is the main source of gas emission, and the dip angle of the coal seam has the greatest influence. A technical system for controlling gas emission from the coal body at the bottom of the mining area is proposed and demonstrated to be effective in engineering tests.
Article
Energy & Fuels
Zhiyuan Liu, Gang Wang, Jinzhou Li, Huaixing Li, Haifeng Zhao, Hongwei Shi, Jianli Lan
Summary: This study analyzed the dynamic characteristics and energy loss laws of water-immersed coal through experiments. The results show that the moisture content of the coal sample affects its mechanical properties and failure mode.
INTERNATIONAL JOURNAL OF COAL SCIENCE & TECHNOLOGY
(2022)
Article
Energy & Fuels
Zhenyang Wang, Gang Wang, Congmeng Hao, Biao Hu, Yuanping Cheng, Zhen Liu, Guansheng Qi
Summary: This study analyzed multifractal characteristics and their effects on gas adsorption/desorption. The results showed that metamorphism and tectonism affected gas adsorption/desorption by changing the coal pore structure. Multifractal parameters have a significant impact on gas adsorption/desorption capacity overall.
Article
Energy & Fuels
Yong Chen, Ronghua Liu, Gang Wang, Jinkui Ma, Jiaokun Wu, Pengfei Wang, Kuan Wu, Xiaomin Guo
Summary: The characteristics of pore structure and gas desorption were studied by exploring the pore difference characteristics and adsorption/desorption experiments of primary coal with different degrees of metamorphism. It was found that the pore volume increases with the increase in metamorphism degree. The distribution of micropores, small pores, and medium-sized pores (by volume) is WY < PM < CY, while the distribution of large pore volume and visible pore volume is WY > PM > CY.
ENERGY SCIENCE & ENGINEERING
(2023)
Article
Engineering, Aerospace
Andre F. P. Ribeiro, Carlos Ferreira, Damiano Casalino
Summary: This study compares a filament-based free wake panel method to experimental and validated numerical data in order to simulate propeller slipstreams and their interaction with aircraft components. The results show that the free wake panel method is able to successfully capture the slipstream deformation and shearing, making it a useful tool for propeller-wing interaction in preliminary aircraft design.
AEROSPACE SCIENCE AND TECHNOLOGY
(2024)
