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Ultra‑High Sensitivity Anisotropic Piezoelectric Sensors for Structural Health Monitoring and Robotic Perception

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Nano-Micro Letters 2025年第2期17卷 432-446页

作者： Hao Yin Yanting Li Zhiying Tian Qichao Li Chenhui Jiang Enfu Liang Yiping Guo State key laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Beijing Vacuum Electronics Research Institute Beijing 100015People’s Republic of China Fundamental Science On vibration Shock and Noise LaboratoryState Key Laboratory of Mechanical System and VibrationSchool of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

Monitoring minuscule mechanical signals,both in magnitude and direction,is imperative in many application scenarios,e.g.,structural health monitoring and robotic sensing ***,the piezoelectric sensor struggles to satisfy the requirements for directional recognition due to the limited piezoelectric coefficient matrix,and achieving sensitivity for detecting micrometer-scale deformations is also ***,we develop a vector sensor composed of lead zirconate titanate-electronic grade glass fiber composite filaments with oriented arrangement,capable of detecting minute anisotropic *** as-prepared vector sensor can identify the deformation directions even when subjected to an unprecedented nominal strain of 0.06%,thereby enabling its utility in accurately discerning the 5μm-height wrinkles in thin films and in monitoring human pulse *** ultra-high sensitivity is attributed to the formation of porous ferroelectret and the efficient load transfer efficiency of continuous lead zirconate titanate ***,when integrated with machine learning techniques,the sensor’s capability to recognize multi-signals enables it to differentiate between 10 types of fine textures with 100%*** structural design in piezoelectric devices enables a more comprehensive perception of mechanical stimuli,offering a novel perspective for enhancing recognition accuracy.

关键词： Flexible piezoelectric filaments Anisotropic Ultra-high sensitivity Structural health detection Texture recognition

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Experimental measurement of tip vortex flow field with/without cavitation in an elliptic hydrofoil

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Journal of Hydrodynamics 2017年第6期29卷 939-953页

作者：彭晓星徐良浩刘玉文张国平曹彦涛洪方文颜开 national key laboratory on ship vibration and noise China Ship Scientific Research CenterWuxi 214082China

In this paper, recent measurements of tip vortex flow with and without cavitation carried out in Cavitation Mechanism Tunnel of China ship Scientific Research Center（CSSRC） are presented. The elliptic hydrofoil with section NACA 662-415 was adopted as test model. High-speed video（HSV） camera was used to visualize the trajectory of tip vortex core and the form of tip vortex cavitation（TVC） in different cavitation situations. Laser Doppler velocimetry（LDV） was employed to measure the tip vortex flow field in some typical sections along the vortex trajectory with the case of cavitation free. Stereo particle image velocimetry（SPIV） system was used to measure the velocity and vorticity distributions with and without cavitation. Series measurement results such as velocity and vorticity distributions, the trajectory of tip vortex core, the vortex core radius, cavity size and cavitation inception number were obtained. The results demonstrated that the minimum pressure coefficient in the vortex core obtained by flow field measurement was quite coincident with the tip vortex cavitation inception number obtained under the condition of high incoming velocity and low air content. And TVC would decrease the vortex strength comparing with the case without cavitation.

关键词： Tip vortex flow field cavitation LDV SPIV HSV measurement data

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Unsteadiness control of laminar junction flows on pressure fluctuations

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Applied Mathematics and Mechanics(English Edition) 2019年第3期40卷 373-380页

作者： Jianhua LIU Shucheng ZHAI E.KUDASHEV Fangwen HONG Kai YAN China ship Scientific Research Center national key laboratory on ship vibration & noise Space Research Institute of Russian Academy of Sciences

Smoke-wire flow visualization is conducted carefully in a laminar junction to explore the physical behavior of laminar junction flows. The two-dimensional(2 D)velocity fields in the 30?plane of a laminar junction flow are acquired by a time-resolved particle image velocimetry(PIV) system at a frame rate of 1 kHz, based on which the unsteady fluctuating pressure fields can be calculated by the multi-path integration method proposed in the literature(GAND, F., DECK, S., BRUNET,V., and SAGAUT, P. Flow dynamics past a simplified wing body junction. Physics of Fluids, 22(11), 115111(2010)).A novel control strategy is utilized to attenuate the unsteadiness of the horseshoe vortices of the laminar junction flow, and the consequent effect on pressure fields is analyzed.

关键词： junction flow horseshoe vortex pressure fluctuation flow visualization

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Investigations on vortex structures for undulating fin propulsion using phase-locked digital particle image velocimetry

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Journal of Hydrodynamics 2021年第3期33卷 572-582页

作者： Ya-qiang Bai Jun Zhang Shu-cheng Zhai Guo-ping Zhang China ship Scientific Research Center Wuxi214082China national key laboratory on ship vibration and noise Wuxi214082China

The Gymnarchus niloticus fish can swim in surging and heaving directions only with a long undulating ribbon fin while keeping its body along almost straight *** features substantially inspire the design of underwater vessels with high maneuverability and station keeping performance,which is characterized by peculiar vortex structures induced by undulating fin *** reveal the propulsion mechanism under the evolution of these complex vortex structures,the variation of velocity field with the undulating fin’s wave phase on cross section and mid-sagittal plane at wave amplitude of 85°is investigated by phase-locked digital particle image velocimetry(DPIV).Through experimental flow field images,two typical vortex structures are clearly identified,i.e.,streamwise vortex and crescent vortex,which is further explained by supplemental numerical simulations using large eddy *** characteristic and its evolution on cross sections and mid-sagittal planes is investigated,and its relationship with thrust,heave force is also *** is found that the two kinds of vortexes induce the main hydrodynamic forces in two directions synchronously,which brings the undulating fin propulsion an extra-ordinal *** research will be useful for understanding the potential mechanism of this novel propulsion and is of great application prospect in designing more maneuverable underwater vehicles.

关键词： Undulating fin propulsion vortex structure phase-locked digital particle image velocimetry(DPIV) hydrodynamic mechanism

An experimental study on the impact behavior of cavitation inside tip clearance of a hydrofoil

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Journal of Hydrodynamics 2023年第6期35卷 1208-1214页

作者： Yan-tao Cao Liang-hao Xu Xiao-xing Peng national key laboratory on ship vibration and noise China Ship Scientific Research CenterWuxi214082China Taihu laboratory of Deepsea Technological Science Wuxi214082China

Tip clearance cavitation is one of the most common cavitation phenomena exist on duct propellers,pumps and some hydraulic turbines,which may lead to erosion of the *** to the influence of the nearby wall,cavitation inside the tip clearance is more complicated than other cases without *** far,the understanding about the impact mechanism of tip clearance cavitation is still *** this paper,to obtain the impact behavior of tip clearance cavitation,a high-speed camera was used to capture the cavitation behavior inside the tip clearance of a hydrofoil,and surface paint coating peeling method was applied to show the impact *** indicated that cavitation around the tip of the hydrofoil was composed of a tip separation cavity and a tip leakage vortex cavity,and the one with contribution to impact was the tip separation *** the comprehensive analysis of the paint peeling region and dynamic behavior of tip separation cavity,the impact was found to be related to the local collapse and rebound of the cloud cavitation shed from the attached *** addition,the influence of tip clearance size on the behavior of tip clearance cavitation was also *** the tip clearance size increased,the tip separation cavity tended to transfer from sheet cavitation to vortex *** findings can provide a sound basis for evaluating the erosion risk arising from the tip clearance cavitation.

关键词： Tip clearance cavitation impact region impact behavior tip clearance size

Suppression of self-sustained oscillations of incompressible flow over aperture-cavities and its mechanisms

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Journal of Hydrodynamics 2022年第5期34卷 876-892页

作者： Wen-wen Zhang Rong-wu Xu Lin He Jia Duan Institute of vibration and Sound Naval University of EngineeringWuhan430033China national key laboratory on ship vibration and noise Naval University of EngineeringWuhan430033China

Experiments and large-eddy simulations(LESs)are conducted to study the effectiveness and the underlying physical mechanisms of a passive control technique for suppressing the self-sustained oscillations of incompressible flow over *** control technique is implemented by installing a wedge block above the chamfered *** experiments are carried out in a low-speed water tunnel with the freestream velocity ranging from 0.4 m/s to 4.4 m/s,while the large-eddy simulations are carried out corresponding to the experiment at a velocity of 4.0 m/*** wall pressure fluctuations measured along the cavity floor show that a significant suppression of the self-sustained oscillations of the shear layers can be achieved by the control ***,the suppression performance is improved as the freestream velocity increases,not limited to the design point of the control *** analysis of numerical simulation results focuses on three aspects,the vorticity fields,the velocity fields and the pressure fields,and the physical effects of the control device on the incompressible aperture-cavity flow are *** mechanisms of suppressing the cavity oscillations are identified from the numerical results,which are the destruction of the large vortex structures by the high frequency vortical excitations,the inhabitation of the intracavity recirculation feedback by introducing the lower shunt flow,and the attenuation of the trailing-edge impingement by thickening the shear layer.

关键词： Cavity oscillations flow control flow-induced noise numerical simulations hydrodynamic noise

Design and Optimization of the Electromagnetic Actuator in Active-Passive Hybrid vibration Isolator

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Sound & vibration 2018年第6期52卷 11-17页

作者： Jianguo Ma Changgeng Shuai Yan Li Institute of noise&vibration Naval University of EngineeringWuhan430033China national key laboratory on ship vibration&noise Wuhan430033China

The design and optimization of actuators are difficult andcritical for the active-passive hybrid vibration control system. Inthis paper, an electromagnetic actuator model is establishedbased on Ohm’s Law for magnetic circuit considering theleakage flux. The 600N electromagnetic actuators are designedand optimized based on ANSYS simulation according to theengineering request. Its transient characteristics are studied. Theeffects of different structural parameters on its output force areanalyzed. The experimental results show that the structureparameters and output force characteristics of the designedelectromagnetic actuators satisfy the practical requirement.

关键词： Electromagnetic actuator finite element analysis hybridvibration isolator structure design

Numerical investigation of the cavitation noise around a marine propeller focusing on the influence of ventilation

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Journal of Hydrodynamics 2023年第4期35卷 630-648页

作者： Shu-jian Lyu Bin Ji Xin-cheng Wang Zhi-wen Zhan Da-hai Zhang State key laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China China ship Development and Design Center National key laboratory on ship Vibration and NoiseWuhan430064China

Cavitation noise around propellers has many adverse *** is still very limited nowadays to inhibit propeller cavitation noise in *** this study,the cavitation noise around a PPTC propeller is simulated using the large eddy simulation(LES)coupled with the porous Ffowcs Williams-Hawkings(PFW-H)*** investigation aims to find a strategy to suppress cavitation noise and analyze the noise suppression *** predicted hydrodynamic results agree well with the experimental data and are utilized in the hydroacoustic *** hydroacoustic results indicate that the pseudo-thickness noise dominates the dominant frequency component of the total cavitation noise due to the effect of cavity evolution,which is one of the reasons why the pseudo-thickness noise dominates the total cavitation noise.A method is found to weaken the cavitation noise through ventilation at the generation location of the sheet cavity(SC).It is worth noting that ventilation inhibits the generation and development of SC by changing the pressure distribution on the suction surface of the blade and pushing away the cavities around the ventilation ***,cavity evolution noise dominates the fluid volume evolution noise under the ventilated cavitating *** significantly attenuates the vapor volume pulsation and thus the cavity evolution noise,which leads to a reduction in pseudo-thickness noise and total cavitation *** ventilation mainly reduces noises at the dominant frequency of the pseudo-thickness noise and the total cavitation noise.

关键词： Cavitation noise ventilation porous Ffowcs Williams-Hawkings(PFW-H)equation large eddy simulation(LES) PPTC propeller

Experimental investigation of vortex generator influences on propeller cavitation and hull pressure fluctuations

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Journal of Hydrodynamics 2020年第1期32卷 82-92页

作者： Hong-bo Huang Yun Long Bin Ji national key laboratory on ship vibration and noise China Ship Scientific Research CenterWiuxi 214082China State key laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China

In this paper,the transient turbulent cavitating flow around a marine propeller behind a ship was investigated experimentally with emphasis on how vortex generator(VG)influences propeller cavitation and hull pressure *** experiments were carried out in China Large Cavitation Channel with the closed test section covering 10.5 m in length and cross-section of 2.2 m^2×2.0m^*** experiment recorded instantaneous cavitation photos of the propeller and pressure fluctuations on the hull *** results demonstrate that without vortex generator,the sheet cavitation inception begins at-50°(310°),and then from-50°(310°)to 30°,the extent and area of sheet cavitation *** vortex generator installed on the hull,the sheet cavitation inception occurs in advance at-60°(300°),and the sheet cavitation expands to larger rotation range due to the vortex *** is shown that the vortex generator with proper geometry and installed location may contribute the highly nonuniform wake to be more uniform,and can make the change of propeller cavitation to be milder,which decrease the pressure fluctuations in this *** analysis indicates that the vortex generator may promote the energy distribution to be more uniform in physical and spectral space in some degree.

关键词： Cavitating flow pressure fluctuations propeller and ship hull vortex generator