An Innovation in Prediction of Transient Sound Radiation

这个研究项目的重点是开发一种创新的技术来计算在固体、静止表面附近任意振动物体的瞬态和稳态声辐射。通过这种方法，参与汽车部件（如侧板，引擎盖和油底壳）设计的工程师能够探索替代设计，以最大限度地降低噪声水平，并满足SAE J986， J1470和ECD51的通过噪声要求。该方法利用Kirchhoff积分理论，根据物体表面速度分布的法向分量，在频域内对辐射声压进行显式求解。时域信号是通过傅里叶反变换得到的。通过上升像源法，考虑了附近固定固体表面声散射的影响。虽然该技术对汽车工业具有直接价值，但由于它处理的是任意振动物体的声辐射，因此其适用性要广泛得多。＊＊＊

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. ***