Article
Acoustics
Chaoyang Jiang, Danielle Moreau, Charitha de Silva, Con Doolan
Summary: This study numerically investigates the noise generation and flow characteristics of a forced-transitioned NACA 0012 airfoil with a micro-tube porous trailing edge. The results show that the micro tube structure reduces low-frequency trailing-edge noise and induces additional high-frequency noise through flow permeation. The interaction between flow permeation and boundary layer turbulence is the main cause for the noise reduction.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Mohammad Amin Faghihi, Hossein Mohammadi, Ehsan Azadi Yazdi, Mohammad Eghtesad, Shabnam Tashakori
Summary: This paper presents an integrated model to study the axial-torsional dynamics of a distributed drill string. By mathematical modeling, the characteristics of the drill string dynamics are explored. The findings contribute to improving drilling efficiency and reducing failures.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Zbynek Sika, Jan Krivosej, Tomas Vyhlidal
Summary: This paper presents a novel design of a compact six degrees of freedom active vibration absorber with six identical eigenfrequencies. The objective is to completely suppress the vibration of a machine structure with six motion components. By utilizing a Stewart platform structure equipped with six active legs, a spatial unifrequency absorber with six identical eigenfrequencies is achieved. The design is optimized using a correction feedback and active delayed resonator feedback.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Zhuogeng Zhang, Hongli Ji, Chongcong Tao, Jinhao Qiu, Li Cheng
Summary: This study introduces a new method to suppress panel flutter in supersonic flow using an add-on acoustic black hole (AABH). Numerical simulations demonstrate that the AABH effectively increases the critical flutter velocity and stabilizes the panel, reducing flutter amplitude.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Jiajia Zhang, Shan Yin, Bingyong Guo, Yang Liu
Summary: This paper presents a theoretical and experimental study on a universal vibro-impact system with bidirectional drift. The system exhibits various bifurcations and unpredictable motions under different excitation frequencies and amplitudes.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Viktor Hruska, Jean-Philippe Groby, Michal Bednarik
Summary: This study numerically and experimentally analyzes the amount and practical source of losses required for rectangular sonic black holes in air to effectively absorb low-frequency sound. The results show that in the presence of solely viscothermal losses, only high-order Fabry-Perrot resonances are likely to be critically coupled in realistic rectangular sonic black holes, resulting in absorption peaks that do not reach unity at low frequencies. To solve this issue, slits of rectangular sonic black holes are partially filled with porous materials, which significantly improves the absorption coefficient, especially at frequencies below the viscous/inertial transition frequency of the porous material.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Silouane de Reboul, Emmanuel Perrey-Debain, Nicolas Zerbib, Stephane Moreau
Summary: This paper presents a frequency domain numerical method for solving the propagation of sound waves in a three-dimensional domain with rotating obstacles. The method uses domain decomposition to embed rotating parts in a cylindrically-shaped domain and employs Frequency Scattering Boundary Conditions to achieve transmission conditions between fixed and rotating domains.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Sandip Chajjed, Mohammad Khalil, Dominique Poirel, Chris Pettit, Abhijit Sarkar
Summary: This paper reports the generalization of the Bayesian formulation of the flutter margin method, which improves the predictive performance by incorporating the joint prior of aeroelastic modal parameters. The improved algorithm reduces uncertainties in predicting flutter speed and can cut cost by reducing the number of flight tests.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Hector E. Goicoechea, Roberta Lima, Fernando S. Buezas, Rubens Sampaio
Summary: In this paper, a comprehensive continuous Cosserat rod model is developed to study the dynamics of a drill-string. The model can simulate the 3-D dynamics of the system, including lateral, axial and torsional motion, and includes damping effects and a velocity-independent bit-rock interaction formulation. The study compares the model's predictions with two other models and finds divergences in the signals obtained with the Cosserat model, indicating that the new continuous approach can capture aspects of the dynamics that cannot be modeled with low-dimensional representations. The study also evaluates the drilling efficiency and finds that axial oscillations have a positive effect on drilling performance, while torsional stick-slip has a negative effect.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Junzeng He, Dong Jiang, Dahai Zhang, Zhenhuan Tang, Qingguo Fei
Summary: An adaptive Gaussian process model-based model updating method for rotor system is proposed in this study, which utilizes unbalance responses data and multi-channel data fusion to construct the objective function of model updating, effectively reducing the computation cost of repeated finite element calculation. Experimental results show that the proposed method has good accuracy and feasibility.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Ju-Hyok Kim, Jong-Hyok Ri, Hyok Jang, Chol-Ung Choe
Summary: This article introduces the centrifugal pendulum vibration absorber and the significant role of geometric nonlinear damping in reducing torsional vibrations in machines. The research findings suggest that geometric nonlinear damping can effectively eliminate multistability and hysteresis in steady states.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Zaiwei Liu, Bin Lin, Xiaohu Liang, Xiaokang Ma, Yangfan Wan
Summary: This paper presents a combined semi-analytical finite element (SAFE) and perfectly matched layer method for accurately predicting the dispersion, attenuation, and polarization modes of surface acoustic waves (SAWs) in materials. The method is validated by comparing the simulated results with exact three-dimensional elasticity theory-based solutions, and the effects of material anisotropy and residual stress on SAWs are discussed. The method is also applied to practical examples and the differences and similarities of two common acoustoelastic theories are discussed.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Yuqi Li, Tianliang Long, Zhong Luo, Chuanmei Wen, Zhimin Zhu, Long Jin, Bing Li
Summary: This study aims to investigate the dynamic and mechanical behaviors of a bolted joint rotor-bearing system affected by pedestal looseness fault. By establishing a dynamic model and conducting experimental research, the dynamic features of pedestal looseness fault are identified.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Justine Carpentier, Jean-Hugh Thomas, Charles Pezerat
Summary: This paper proposes an improved method for the identification of vibration sources on a car window using the corrected force analysis technique. By redefining inverse methods in polar coordinates, more accurate results can be obtained.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Panxu Sun, Yadan Yan, Hong Yang
Summary: This paper proposes a complex mode superposition method based on the hysteretic damping model, which can effectively consider the non-proportional damping characteristics of hybrid structures. The method is suitable for calculating the time-domain dynamic responses of hybrid structures that are sensitive to frequency variation and have strong non-proportional damping characteristics.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Sonya Tiomkin, Justin W. Jaworski
Summary: This paper presents an analytic solution for the aerodynamic noise generated by a traveling wavepacket passing near the edge of a rigid semi-infinite flat plate. The solution is derived in the time domain for a wavepacket of either constant or spatially-varying wavenumber, and novel expressions are obtained for the incident and scattered sound fields. The study shows that the wavenumber modification has a significant effect on the incident field but not on the scattered field amplitude, while the phase difference between the incident and scattered fields depends strongly on the spatial variation in the wavepacket wavenumber.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Pascal Zeise, Bernhard Schweizer
Summary: Air ring bearings are an improved version of classical air bearings, providing better damping behavior and allowing operation above the linear threshold speed of instability. However, there is a risk of dangerous vibrations in certain rotor systems, which can be addressed by considering ring tilting effects.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Thermodynamics
Wen Li, Jingxin Wang, Linlin Tian, Chuling Zhu, Ning Zhao
Summary: The rebound dynamics of a microscale supercooled water droplet on a cold superhydrophobic surface were numerically studied. Four different regimes were observed during the impacting-freezing process, and the results were affected by the cold surface temperature, impact velocity, droplet diameter, and supercooled degree.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Xuan Wang, Chen Kong, Minghao Ren, Aihan Li, Juntao Chang
Summary: This study proposes a fast-predicting scheme for the temperature distribution of aeroengine combustor using deep learning. Different network structures are trained and compared to predict the temperature field under different dataset processing methods. The results show that fully-connected networks and fusion convolutional networks have good predictive capabilities. Introducing reference data to process the dataset significantly improves the models' prediction ability for equivalent ratio conditions far from the training dataset.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Wei Su, Dongxu Ma, Xu Jin, Zhongyan Liu, Dahai Zhao
Summary: Frost formation is a complex nonlinear physical process, and the inclination angle and surface wettability have significant effects on the frosting and defrosting characteristics.
APPLIED THERMAL ENGINEERING
(2024)
