A modal model for diffraction by a contiguous array of rectangular grooves in an acoustically-hard plane is extended to predict the free space acoustic field from a point source above such a structure. Keith Attenborough discusses an approximate effective impedance model for grooved surfaces.

Read the Study

K. Attenborough, I. Bashir and S. Taherzadeh, Exploiting ground effects for surface transport noise abatement, Noise Mapping Journal, 3 1- 25 (2016)http://www.degruyter.com/view/j/noise.2016.3.issue-1/issue-files/noise.2016.3.issue-1.xml

S. Mellish, S. Taherzadeh and K. Attenborough, Use of a modal model in predicting the propagation of sound from a point source over a grooved surface, Quart. J. Mech. Appl. Math. (2021) 73(4) 367–382 doi:10.1093/qjmam/hbaa018 

“Modal model prediction of surface waves and resonant characteristics of rectangular grooved gratings,” was published online today, 05-17-2023, in The Journal of the Acoustical Society of America (Vol.153, Issue 5). It may be accessed via the link below:
https://doi.org/10.1121/10.0019473
DOI: 10.1121/10.0019473

Image courtesy of interviewee. May 16, 2023