In the numerical implementation of the boundary element method to exterior acoustic problems, the approximating equations give incorrect results for the surface pressure when the frequency is in the neighbourhood of some critical values.
On the other hand, expressive conduct shares a protected purpose of expression with core speech, but a regulable method of expression with exterior product design.
Zhang and Chen [The boundary point method for the calculation of exterior acoustic radiation problem, Journal of Sound and Vibration 228 (1999) 761 772] proposed a boundary point method (BPM) for exterior acoustic problems.
In addition, a dislocation distribution layer method for the solution of exterior BVP is also suggested.
Later, Wu commented twice [Sean F. Wu, Comments on "The boundary point method for the calculation of exterior acoustic radiation" (by S.Y. Zhang, X.Z.
Chen, C.X. Bi, Reply to the comments on "The boundary point method for the calculation of exterior acoustic radiation" (by S.Y. Zhang, X.Z.
Chen, C.X. Bi, Reply to the comments on "Reply to the comments on 'The boundary point method for the calculation of exterior acoustic radiation' (by S.Y. Zhang, X.Z.
Chen, Journal of Sound and Vibration 228(4) (1999) 761 772), Journal of Sound and Vibration, 298 (2006) 1173]; Sean F. Wu, Comments on "Reply to the comments on 'The boundary point method for the calculation of exterior acoustic radiation' (by S.Y. Zhang, X.Z.
Wave envelope elements provide an alternative to boundary element methods for the solution of exterior wave problems.
