Skip to contents

BCMS

Source: vignettes/bcms/index.Rmd
index.Rmd

Overview

Unvalidated Experimental
Theory Implementation

The bent-cylinder modal-series model (BCMS) calculates near-broadside scattering from straight or uniformly bent circular cylinders while retaining the FCMS cross-sectional modal solution.

Core idea

Use the straight-cylinder partial-wave coefficients locally, then replace the straight axial coherence factor with the Fresnel-integral correction for uniform curvature (Stanton 1989).

Best for

  • Uniformly bent, constant-radius cylinders near broadside
  • Isolating curvature-driven coherence changes from cross-sectional boundary physics
  • Comparisons with the straight FCMS limit

Supports

  • Cylinder shapes carried by FLS or GAS scatterers
  • Curvature supplied through the shape’s radius-of-curvature ratio
  • Liquid-filled, gas-filled, fixed-rigid, and pressure-release boundaries

Main assumptions

  • Uniform centerline curvature and constant circular cross-section
  • Broadside or near-broadside incidence
  • Curvature changes axial coherence but not local modal coefficients
  • No arbitrary bending, torsion, taper, or fully three-dimensional boundary solve

Validation status

  • BCMS is currently marked experimental because the documented checks are internal coherence reconstructions rather than an external benchmark or software-comparison ladder.

Family pages

  • Implementation: curvature input, boundaries, output, and internal checks
  • Theory: Fresnel coherence correction and the straight-cylinder limit

References

Stanton, T. K. 1989. “Sound Scattering by Cylinders of Finite Length. III. Deformed Cylinders.” The Journal of the Acoustical Society of America 86 (2): 691–705. https://doi.org/10.1121/1.398193.