CAJ | 학술논문

利用振动模态及声辐射模态分析水下有限长圆柱壳低频模态辐射特性。计算各阶周向振动模态对辐射声功率贡献；将各阶周向模态下轴向振动模态分为奇、偶模态组，分析低频范围内振动模态组与声辐射模态对应关系；以主导声辐射模态声功率为目标函数对水下有限长圆柱壳低频声辐射进行有源控制。结果表明，低频范围内水下简支圆柱壳受径向点力激励时，仅前几阶周向振动模态对辐射声功率有贡献；同一周向振动模态下轴向为奇（偶）振动模态组产生的声功率与具有相同周向阶数而轴向为偶（奇）声辐射模态产生的声功率对应。通过控制前几阶主导声辐射模态即可完成对水下有限长壳体低频辐射噪声抑制。
이용진동모태급성복사모태분석수하유한장원주각저빈모태복사특성。계산각계주향진동모태대복사성공솔공헌；장각계주향모태하축향진동모태분위기、우모태조，분석저빈범위내진동모태조여성복사모태대응관계；이주도성복사모태성공솔위목표함수대수하유한장원주각저빈성복사진행유원공제。결과표명，저빈범위내수하간지원주각수경향점력격려시，부전궤계주향진동모태대복사성공솔유공헌；동일주향진동모태하축향위기（우）진동모태조산생적성공솔여구유상동주향계수이축향위우（기）성복사모태산생적성공솔대응。통과공제전궤계주도성복사모태즉가완성대수하유한장각체저빈복사조성억제。
The radiation characteristics of a submerged finite cylindrical shell at low frequencies were investigated based on its vibration modes and acoustic radiation modes.The contribution of each circumferential vibration mode to the radiated sound was observed.Then,under a certain circumferential mode,axial vibration modes were divided into an axial odd-mode group and an axial even-mode group,and the correspondance relationships between each vibration mode group and acoustic radiation modes at low frequency were inspected.The results show that at low frequencies,only the first few circumferential vibration modes contribute to the sound power radiated from a submerged finite cylindrical shell excited by radial point forces;under a certain circumferential mode,the sound power radiated by the odd (even)axial vibration modes group corresponds to the acoustic radiation mode with the same circumferential mode and even (odd) axial modes.The sound power radiated from a submerged finite cylindrical shell can be restrained by controlling the sound power of the dominant radiation modes.