Wang Q.,Northwestern Polytechnical University |
Hou H.,Northwestern Polytechnical University |
Chen Z.,Northwestern Polytechnical University |
Qin X.,CSIC The 705th Research Institute |
Huang Y.,Northwestern Polytechnical University
Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University | Year: 2014
In order to verify the feasibility of the sound source identification method for underwater moving vehicle, a simulation test system is developed. A non-uniform hydrophone linear array is designed and the moving sound source identification is achieved using respectively the CBF (Conventional Beamforming) method and the DAMAS (Deconvolution Approach for the Mapping of Acoustic Sources) method. We carry out the experiments in a reservoir for respectively the moving mode of an underwater vehicle, simulating successfully the characteristics of underwater vehicle sound radiation and the possibility of the proposed sound source identification method. The results and their analysis show preliminarily that: (1) the DOA deviation of CBF and DAMAS are both less than 0.20; (2) DAMAS has superior performance and it is more suitable for underwater vehicle sound source identification. ©, 2014, Northwestern Polytechnical University. All right reserved.
Xu W.-W.,Zhejiang University |
Wu D.-Z.,Zhejiang University |
Lu R.,CSIC The 705th Research Institute |
Chen Y.-W.,Zhejiang University |
Wang L.-Q.,Zhejiang University
Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics | Year: 2013
The noise characteristics of the air impingement on a rigid wall are experimentally and theoretically investigated, in order to reduce the noise. It is indicated by the experiment in which high speed air impingement on surface of the baffle made by different materials that the less modulus of elasticity, the less noise. The material of low modulus of elasticity tents to absorb gas energy more easily and it reduces the amplitude of pulsating force effect on the baffle, thus reducing the noise of jets impact. The distance between nozzle and baffle have a significant influence on jet noise, it shows that the increases of distance reduce the jet noise. However, the low-frequency noise increases. Turbulent kinetic energy produced in the impact of high-speed airflow decides the sound level, so changing the material of the surface of baffle becomes an effective method to reduce the sound of noise.