FDTD stability, boundaries and physical validation
Research context
research method · conditional · As of 2026-10-10
Yee FDTD staggers electric/magnetic fields in space and time to approximate Maxwell curl evolution.
Key knowledge
Yee FDTD staggers electric/magnetic fields in space and time to approximate Maxwell curl evolution. In a uniform isotropic nondispersive medium, the three-dimensional explicit scheme requires c_mΔt√(Δx⁻²+Δy⁻²+Δz⁻²)≤1. Stability alone does not guarantee correct phase, interfaces or absorption; finite PML and numerical dispersion need convergence tests.
Values and equations
c_mΔt√(Δx⁻²+Δy⁻²+Δz⁻²)≤1
- c_m
- Medium wave speed m s⁻¹
- Δt
- Time step s
- Δx,Δy,Δz
- Grid spacings m
Conditions and scope
- Cartesian Yee grid, constant-medium wave speed c_m and applicable explicit update; dispersive/nonlinear material updates can impose additional restrictions.
- Specify source, initial fields, constitutive law and boundary/PML parameters; check divergence constraints, flux/energy balances, mesh/time refinement and analytic or measured benchmarks.
Sources · 3
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
John B. Schneider / Washington State University3 sources
- Understanding FDTD · Three-dimensional methodJohn B. Schneider / Washington State UniversityCourse notes · PDF
- Understanding FDTD · Numerical dispersionJohn B. Schneider / Washington State UniversityCourse notes · PDF
- Understanding FDTD · Perfectly matched layerJohn B. Schneider / Washington State UniversityCourse notes · PDF
Evidence and review
Inspected §§9.3, 9.7: Yee staggering, explicit Maxwell updates and unequal-grid stability bound; source check dated 2026-10-10. Scope is limited to the cited statements, equations and assumptions, not the whole publication. Inspected §§7.3–7.5: harmonic grid analysis, dispersion and impedance error; source check dated 2026-10-10. Scope is limited to the cited statements, equations and assumptions, not the whole publication. Inspected §§11.4–11.6: split/unsplit absorbing layer and finite discretized implementation; source check dated 2026-10-10. Scope is limited to the cited statements, equations and assumptions, not the whole publication.
2026-10-10 · Author source inspection of the displayed claim, model assumptions and equations; independent exact-content and branch-inventory review is a separate gate. Contemporary status is a dated snapshot, not a promise of ongoing monitoring.
Entry details
Permanent link to this entry ↗- Record identity
- research-physics-fdtd-conservation-stability
- Revision
- research.1
- Structured reference record
- Postgraduate & research reference