http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
김현철(Hyun-Cheol Kim),박형길(Hyoung-Gil Park) 한국해양공학회 2015 韓國海洋工學會誌 Vol.29 No.2
In the initial ship design stage, performance predictions are generally carried out before and after the hull form design. The former is based on the main dimensions and power information, and the latter is based on the geometry of the hull form and propeller. This paper deals with the practical application of neural networks for the prediction of a ship`s performance factors before and after the hull form design. For this, the hull form parameters that affect the performance are studied, and an optimal neural network structure based on the SSMB database is constructed. By comparing the results predicted by neural networks and the model test results, we confirmed that neural networks can be applied to practically evaluate the performance in the initial ship design stage.
공기층 음향반사 현상을 이용한 프로펠러 캐비테이션 유발 가진력 저감
이정훈(Jeung-Hoon Lee),이경준(Kyung-Jun Lee),박형길(Hyoung-Gil Park) 한국소음진동공학회 2017 한국소음진동공학회 논문집 Vol.27 No.6
Single nozzle arrangement in the full-scale ship reveals that a significant reduction of propeller cavitation induced pressure amplitude is possible at the outside of air-bubble layer, where the isolation effect of the air is not involved. Resulting hull-vibration reduction is approximately 75 %. Instead of excessive consumption of air, that is, considerably small amount is necessary for a reduction of propeller excitation, which can make the constitution of relevant system simple. Hence the purpose of this study is to provide a physical proof for such a beneficial phenomenon. By approximating the solution of acoustic reflection from a bubble, we could find that phase-reversal reflection provoking a destructive interference is the main reasoning for a pressure reduction outside the layer.