Index of content:
Volume 118, Issue 2, August 2005
- ARCHITECTURAL ACOUSTICS 
Reflection of a spherical wave by acoustically hard, concave cylindrical walls based on the tangential plane approximation118(2005); http://dx.doi.org/10.1121/1.1944527View Description Hide Description
The tangential plane approximation (TPA) is introduced to investigate the spherical wave reflection from smooth concave cylindrical walls, and as a practical calculation scheme, asymptotic expression of the reflected sound from that surface with a relatively large dimension is derived. The physical condition under which TPA holds is derived for the spherical wave incidence; moreover, the essential properties of the reflected sound from the curved walls, which cannot be treated by the geometrical acoustics, are discussed through the numerical calculation for infinitely long cylinders. A formula of the reflection factor of the two-dimensional curved surface is obtained for the purpose of the room acoustical design. This formula coincides with that based on the geometrical acoustics when the frequency is infinitely high.