The problem of active structural acoustic control in an enclosure using radiation mode is investigated. The response of the coupled enclosure is derived in terms of radiation modes. The potential energy in the enclosu...The problem of active structural acoustic control in an enclosure using radiation mode is investigated. The response of the coupled enclosure is derived in terms of radiation modes. The potential energy in the enclosure can be decomposed into independent parts and the radiation modes contribute to potential energy independently. The control strategy for minimizing first G radiation modes with large radiation efficiency is proposed, and the optimal model of control forces is presented. Finally, a numerical simulation for minimizing sound transmission into a rectangular enclosure using the proposed method is conducted. Simulation results indicate that one control force can control one radiation mode and controlling the first four-order radiation modes with four control forces can achieve significant potential energy reduction at the low frequency range.展开更多
The acoustic radiation mode of plane,whose radiating operator is constructed by Rayleigh integral,is investigated in the time domain and its physical meaning is given.The relationship between the acoustic radiation mo...The acoustic radiation mode of plane,whose radiating operator is constructed by Rayleigh integral,is investigated in the time domain and its physical meaning is given.The relationship between the acoustic radiation modes of time domain and frequency domain is discussed.It is verified that the acoustic radiation modes are the natural property of the radiator and they can be obtained by different methods.These time domain radiation modes,whose shapes are only dependent on the geometry size and shape of the radiator,can radiate sound power independently.Especially,the first time domain radiation mode accounts for most of the sound radiation.All these simplify the calculation and control of the structure-borne sound power.Based on these observations,the sound power radiated from the vibrating plate is estimated by the time domain radiation mode for verifying the proposed method.The influence factors on the estimating accuracy in different conditions are discussed.展开更多
Based on the radiation modes, an active control strategy is presented for sound radiation from elastic structures with an example of simply supported rectangular panel. The physical characteristics and mathematical me...Based on the radiation modes, an active control strategy is presented for sound radiation from elastic structures with an example of simply supported rectangular panel. The physical characteristics and mathematical meaning of the radiation modes are analyzed. The radiation efficiency of radiation mode falls off very rapidly with the increase of modes order at low frequency. A new control strategy is developed in which by canceling the adjoint coef- ficient of the first k radiation modes, the sound powers of the first k radiation modes is zero theoratically. The numerical calculation is made by using point force actuators as control forces.展开更多
Beam-frequency-scanning detection and point-to-point communication typically differ significantly in bandwidth and polarization characteristics,requiring two separate antennas in conventional designs.This paper propos...Beam-frequency-scanning detection and point-to-point communication typically differ significantly in bandwidth and polarization characteristics,requiring two separate antennas in conventional designs.This paper proposes a method to integrate a dual-mode radiation of narrowband circular polarization(CP)into a broadband linearly polarized(LP)beam-scanning leaky-wave antenna(LWA)using a full spoof surface plasmon polariton(SSPP)system.First,a grooved SSPP unit and its complementary structure are used with periodic mode modulation to achieve continuous vertically polarized(V-pol)dual-beam scanning from backward to forward.By periodically embedding spoof localized surface plasmon(SLSP)units,strong coupling between SLSPs and SSPPs is enabled under resonant conditions.Then,CP radiation is generated due to the rotating electric-field vectors of SLSPs.Experiment and simulation results demonstrate continuous V-pol beam scanning from−30°to 22°across 4.25–6.75 GHz,including effective broadside radiation.Notably,at 5.4 GHz,the antenna radiates right-handed circularly polarized(RHCP)and left-handed circularly polarized(LHCP)waves in opposite broadside directions.Compared with existing technologies,the insertable CP radiation allows the antenna to enable two significantly different operating modes,which can be applied in combined beam-scanning detection and narrowband satellite emergency communication,greatly improving system integration.展开更多
We theoretically investigate transmission-type SPR sensors with novel metallic-dielectric mixed gratings by rig- orous coupled-wave analysis （RCWA）, compared to the conventional dielectric gratings based structure. ...We theoretically investigate transmission-type SPR sensors with novel metallic-dielectric mixed gratings by rig- orous coupled-wave analysis （RCWA）, compared to the conventional dielectric gratings based structure. It is found that the transmittance efficiency and the full width at half-maximum （FWHM） of the transmission curve can be modulated by increasing or decreasing the metallic part. Therefore, appropriate proportion of metal part will induce enhancement factor of sensor merit. Furthermore, this novel structure will also bring enhancement of resonant angle shift, which can be explained by plasmonie interpretation based on a surface limited increase of interaction area and excitation of localized surface plasmons （LSPs）. The proposed configuration has a wide range of potential applications not only as sensor but also other optical devices.展开更多
基金Supported by the National Natural Science Foundation of China(50375027,50575041)~~
文摘The problem of active structural acoustic control in an enclosure using radiation mode is investigated. The response of the coupled enclosure is derived in terms of radiation modes. The potential energy in the enclosure can be decomposed into independent parts and the radiation modes contribute to potential energy independently. The control strategy for minimizing first G radiation modes with large radiation efficiency is proposed, and the optimal model of control forces is presented. Finally, a numerical simulation for minimizing sound transmission into a rectangular enclosure using the proposed method is conducted. Simulation results indicate that one control force can control one radiation mode and controlling the first four-order radiation modes with four control forces can achieve significant potential energy reduction at the low frequency range.
基金Supported by the Senior Qualified Personnel Research Foundation of Jiangsu University(Grant No.07JDG070)the Social Development Foundation of Zhenjiang(Grant No.SH2008015)
文摘The acoustic radiation mode of plane,whose radiating operator is constructed by Rayleigh integral,is investigated in the time domain and its physical meaning is given.The relationship between the acoustic radiation modes of time domain and frequency domain is discussed.It is verified that the acoustic radiation modes are the natural property of the radiator and they can be obtained by different methods.These time domain radiation modes,whose shapes are only dependent on the geometry size and shape of the radiator,can radiate sound power independently.Especially,the first time domain radiation mode accounts for most of the sound radiation.All these simplify the calculation and control of the structure-borne sound power.Based on these observations,the sound power radiated from the vibrating plate is estimated by the time domain radiation mode for verifying the proposed method.The influence factors on the estimating accuracy in different conditions are discussed.
基金the National Natural Science Foundation of China (No.50075O36).
文摘Based on the radiation modes, an active control strategy is presented for sound radiation from elastic structures with an example of simply supported rectangular panel. The physical characteristics and mathematical meaning of the radiation modes are analyzed. The radiation efficiency of radiation mode falls off very rapidly with the increase of modes order at low frequency. A new control strategy is developed in which by canceling the adjoint coef- ficient of the first k radiation modes, the sound powers of the first k radiation modes is zero theoratically. The numerical calculation is made by using point force actuators as control forces.
基金National Natural Science Foundation of China(62401133,62071117,62288101)111 Project(111-2-05)+3 种基金Natural Science Foundation of Jiangsu Province(BK20230192)Science and Technology Research Funds of Wuxi TaihuLight Program(K20231007)Sichuan Province Engineering Research Center for Broadband Microwave Circuit High Density IntegrationYoung Elite Scientists Sponsorship Program by Jiangsu Association for Science and Technology.
文摘Beam-frequency-scanning detection and point-to-point communication typically differ significantly in bandwidth and polarization characteristics,requiring two separate antennas in conventional designs.This paper proposes a method to integrate a dual-mode radiation of narrowband circular polarization(CP)into a broadband linearly polarized(LP)beam-scanning leaky-wave antenna(LWA)using a full spoof surface plasmon polariton(SSPP)system.First,a grooved SSPP unit and its complementary structure are used with periodic mode modulation to achieve continuous vertically polarized(V-pol)dual-beam scanning from backward to forward.By periodically embedding spoof localized surface plasmon(SLSP)units,strong coupling between SLSPs and SSPPs is enabled under resonant conditions.Then,CP radiation is generated due to the rotating electric-field vectors of SLSPs.Experiment and simulation results demonstrate continuous V-pol beam scanning from−30°to 22°across 4.25–6.75 GHz,including effective broadside radiation.Notably,at 5.4 GHz,the antenna radiates right-handed circularly polarized(RHCP)and left-handed circularly polarized(LHCP)waves in opposite broadside directions.Compared with existing technologies,the insertable CP radiation allows the antenna to enable two significantly different operating modes,which can be applied in combined beam-scanning detection and narrowband satellite emergency communication,greatly improving system integration.
文摘We theoretically investigate transmission-type SPR sensors with novel metallic-dielectric mixed gratings by rig- orous coupled-wave analysis （RCWA）, compared to the conventional dielectric gratings based structure. It is found that the transmittance efficiency and the full width at half-maximum （FWHM） of the transmission curve can be modulated by increasing or decreasing the metallic part. Therefore, appropriate proportion of metal part will induce enhancement factor of sensor merit. Furthermore, this novel structure will also bring enhancement of resonant angle shift, which can be explained by plasmonie interpretation based on a surface limited increase of interaction area and excitation of localized surface plasmons （LSPs）. The proposed configuration has a wide range of potential applications not only as sensor but also other optical devices.
