利用辐射模态计算振动结构辐射声功率

Estimating Acoustic Power Radiated from Vibrating Structure Using Radiation Modes

在时域里运用辐射模态方法给出振动结构辐射声功率的计算公式,由于这些辐射模态能独立地辐射声功率,结构辐射的声功率可以表示为这些模态辐射声功率的线性叠加;特别是结构辐射声功率主要由第一阶辐射模态的声功率所决定,这使得计算声功率得以简化;通过拉格朗日中值定理分析了影响结构辐射声功率计算精度的因素;在此基础上,运用辐射模态进行振动结构辐射声功率的数值计算,并分别对影响计算精度的因素和计算结果进行了讨论分析。

In time-domain, the radiation modes were used to estimate the transient sound power radiated from vibrating structures. Since each radiation mode could radiate independently, the sound power radiated from a radiator could be expressed as the sum of the sound power of each radiation mode. Especially the first radiation mode radiated much more strongly than other modes. So the sound power might be obtained from a truncated form of sound power formulation using only first terms. This simplified the calculation of the structural-borne sound power. The factors that influenced the sound power calculation accuracy were analyzed by Lagrange differential mean value theorem. Finally, a numerical simulation was employed to compute the transient sound power for verification. The simulation results in different conditions were discussed and analyzed.