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Ji Woo Yoo;Hun Park;Ji Un Lee
- The Journal of the Acoustical Society of Korea
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- v.42 no.1
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- pp.1-6
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- 2023
Sound radiated from a structure in vibration is an important physical characteristic to evaluate vibro-acoustic problem. Although sound radiation power can be typically obtained by intensity measurement, long measuring time and strict measuring condition remain difficult. As an alternative method, simulation-based estimation can be taken into account and its accuracy is known to be acceptable. However, difficulty still lies in that specialized softwares may be necessary to obtain sound radiation power and radiation efficiency. In this context, this study suggests two methods using an ordinary FE method to calculate sound radiation power. They are well-known reciprocity technique and p-p method, which are basically test methods. It is shown that either method can practically estimate sound radiation in the frame of conventional Finite Element Method (FEM). The methods and their corresponding limit are discussed with some results.
https://doi.org/10.7776/ASK.2023.42.1.001 인용 PDF

Kang, Myunghwan;Yi, Jongju;Han, Seungjin;Bae, Sooryong;Jung, Woojin
- Transactions of the Korean Society for Noise and Vibration Engineering
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- v.24 no.12
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- pp.992-998
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- 2014
Acoustic radiation efficiency is one of the important factors in the prediction of underwater radiated noise of ships. A ship has much equipment to operate successful mission in a ship. Most of equipment is running simultaneously as multi-excitation and becomes the source of underwater radiated noise. In many cases of multi-excitation, phase difference between multi-excitation is not considered. Because vibration response under multi-excitation is the vector sum of each single excitation, acoustic radiation efficiency based on surface velocity field can be affected by phase of excitation. In this study, acoustic radiation efficiency of a plate on air and a stiffened cylindrical model in water under multi-excitation with phase difference is investigated.
https://doi.org/10.5050/KSNVE.2014.24.12.992 인용 PDF KSCI KPUBS HTML

Han, Seungjin;Lee, Jongju;Kang, Myunghwan
- Transactions of the Korean Society for Noise and Vibration Engineering
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- v.24 no.11
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- pp.876-882
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- 2014
This study investigates an efficient method to estimate the total acoustic radiation power of submerged circular cylindrical structures. Since the acoustic radiation power of submerged vehicles can be changed during the operation, the estimation for its monitoring onboard is required to accomplish the missions. The total acoustic radiation power is estimated using the measured velocity and the calculated radiation efficiency of the surface which consists of submerged rectangular plate elements. Experiments are carried out to validate the estimation approach. Comparisons of the estimation results with the measurements show that they are in a good agreement for the mid-high frequency range and match well for the cases of different excitation locations which correspond to the different operation modes of underwater vehicles as well. Therefore, this estimation method can be applied effectively to the development of the radiated noise monitoring-system.
https://doi.org/10.5050/KSNVE.2014.24.11.876 인용 PDF KSCI KPUBS HTML