Numerical Investigation of The Submarine Sail With Different Aspect Ratio For Acoustic Target Strength Reduction

The concept of aspect ratio comes from the rudder and wing design. In this paper, the aspect ratio of a vertical-type submarine sail is defined as the ratio of width to height of its projection area in the abeam direction. Under the condition that the projection area in the abeam direction is constant, we mainly analyzed the influence of several different aspect ratios on the acoustic target strength(TS) of the submarine sail. Combined with the finite element method(FEM) and plate element method(PEM), the TS of several submarine sails with the increasing aspect ratio is calculated.The result shows that: 1)the larger the aspect ratio is, the smaller the total TS level of the submarine sail is, and the smaller the intensity of the submarine is in most medium-low frequency band. 2)in the low frequency band, the maximum value of the TS of each submarine sail is close to each other, but when the frequency is higher than 3kHz, the maximum value of the TS decreases with the increase of aspect ratio. 3)when the frequency is 5000Hz or above, the TS of the submarine sail with large aspect ratio is lower than that of the submarine sail with small aspect ratio, and the larger the aspect ratio is, the more the TS decreases.