锥形声源的二次谐波声场分布

The second harmonic generation of a conical sound source

本文推导了锥形声源的非线性二次谐波声场分布。理论表明锥形源二次谐波声场沿径向呈Bessel函数分布，且与传播距离无关。另一个重要结论是这种声场的二次谐波束宽刚好为基波的1／2，而非一般情况下的1／倍，此外，我们指出了这种声束在非线性参量B/A成象或测量中潜在的应用价值．

Abstract: The second harmonic sound beam distribution nonlinearly generated by a conical source has beed derived. Theoretical results indicate that the second harmonic beam is distributed as a Bessel function along the radial direction, and independent of the propagation distance. Another important feature is that the beamwidth of the second harmonic component is just equal to 1/2 times as that of the fundamental, not as 1/ times in the general cases. A potential application of this sound beam in the acoustic nonlinear parameter B/A imaging or measurement is also discussed.