An Innovation in Prediction of Transient Sound Radiation

9414424吴这项研究项目的重点是开发一种创新的技术，计算在固体静止表面附近运动的任意振动物体的瞬变和稳态声辐射。通过这种方法，参与汽车部件(如侧面板、引擎盖和油底壳)设计的工程师能够探索替代设计，以将噪声水平降至最低，并满足SAE J986、J1470和ECD51的通过噪声要求。该方法利用基尔霍夫积分理论，根据物体表面速度分布的法向分量，在频域中得到辐射声压的显式解。使用逆傅立叶变换来获得该时域信号。提出了一种改进的像源法，考虑了邻近固体静止表面的声散射效应。虽然这项技术对汽车工业具有立竿见影的价值，但它的适用性要广泛得多，因为它处理的是来自任意振动物体的声辐射。***

9414424 Wu This research project focuses on the development of an innovative technique calculate transient as well as steady-state acoustic radiation from an arbitrarily vibrating object moving in the proximity of a solid, stationary surface. With this method, engineers involved with the design of automotive components such as side panels, hoods and oil pans are able to explore alternative designs for minimizing the noise levels and satisfying the pass-by noise requirements SAE J986, J1470 and ECD51. The approach uses an explicit form of solution for the radiated acoustic pressure in the frequency domain in terms of the normal component of the velocity distribution on the surface of an object via the Kirchhoff integral theory. The time-domain signal is obtained using an inverse Fourier transformation. The effect of sound scattering from a nearby solid, stationary surface is accounted for by rising the image source method. Although the technique is of immediate value to automotive industry, its applicability is much broader since it deals with acoustic radiation from an arbitrarily vibrating object. ***