다상유동 RANS법을 이용한 수상 함정 주위 기포 층 두께 예측

다국어 초록 (Multilingual Abstract)

This paper shows the numerical analysis of bubbly flows generated by an air bubble masking belt installed in the midships of a surface ship. Numerical simulations were performed using the Reynolds Averaged Navier-Stokes(RANS) Eulerian multiphase(EMP) flow method and the bubble layer thickness around the model and full scale ship, bubble diameter distribution, and changes in hull resistance were investigated. The layer of bubbles became thicker downstream of the both hulls as the air flow rate increased. Since the large bubbles moving downstream of the hulls rose to the free surface due to the buoyancy, the average diameter of the bubbles inside the bubble layers tended to decrease as it went downstream. Although the thickness of bubble layers according to the air flow rates at the model and full scale conditions showed a tendency to roughly follow the scale ratio, a further study on the accurate correlation should be conducted in the future. Both the model and full scale ship showed an increase in pressure resistance after air injection, and a decrease in friction resistance. The distribution of air bubbles in the propeller planes followed the nominal wake characteristics, showing more bubbles at the full scale conditions.