A Conformal FDTD Algorithm with Distorted Grid Face Filtering for Enhanced Efficiency

Authors

  • Chenshu Liu School of Information and Communications Engineering Xi’an Jiaotong University, Xi’an 710049, China
  • Kaihang Fan School of Information and Communications Engineering Xi’an Jiaotong University, Xi’an 710049, China
  • Juan Chen School of Information and Communications Engineering Xi’an Jiaotong University, Xi’an 710049, China

DOI:

https://doi.org/10.13052/2026.ACES.J.410303

Keywords:

Conformal finite-difference time-domain (CFDTD), curved targets, grid face filtering, time step reduction

Abstract

The finite-difference time-domain (FDTD) method suffers from accuracy loss when applied to curved targets due to the staircase approximation. To improve the surface fitting accuracy of curved perfect electric conductor (PEC) objects, the conformal finite-difference time-domain (CFDTD) has been introduced. However, when high-precision conformal cell fitting is performed, the time step in CFDTD is significantly reduced by the presence of distorted small cells, leading to much lower computational efficiency. In this paper, a novel PEC CFDTD algorithm with distorted grid face filtering is proposed, which allows a larger time step. By deriving the stability condition of CFDTD, a Conformal Distortion Index (CDI) is defined and used as a filtering criterion. The conformal cells are retained in regions with low CDI, while areas with high CDI are reverted to the staircase mesh. A sensitivity study on a PEC sphere is used to determine an optimal filtering ratio of 5%, under which the proposed method greatly improves computational efficiency while incurring only a minimal loss in accuracy. Numerical examples are presented to validate the effectiveness of the proposed method.

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Author Biographies

Chenshu Liu, School of Information and Communications Engineering Xi’an Jiaotong University, Xi’an 710049, China

Chenshu Liu was born in Hubei, China, in 2002. She received her B.S. degree in Electronic and Information Engineering from Xi’an Jiaotong University, Xi’an, in 2024, where she is currently working toward an M.S. degree in Electromagnetic Field and Microwave Technology. Her current research interests include computational electromagnetics.

Kaihang Fan, School of Information and Communications Engineering Xi’an Jiaotong University, Xi’an 710049, China

Kaihang Fan received the B.S. degree in electronic information science and technology from Xidian University, Xi’an, China, in 2014, and the Ph.D. degree in radio physics, Xidian University, Xi’an, in 2021. She is currently an Assistant Professor with the School of Information and Communications Engineering, Xi’an Jiaotong University, Xi’an. Her current research interests include computational electromagnetics numerical methods and multi-physics field simulation.

Juan Chen, School of Information and Communications Engineering Xi’an Jiaotong University, Xi’an 710049, China

Juan Chen was born in Chongqing, China. She received the Ph.D. degree from Xi’an Jiaotong University, Xi’an, in 2008, in electromagnetic field and microwave technology. She is currently working in Xi’an Jiaotong University, Xi’an, as a professor. Her research interests include computational electromagnetics and microwave device design.

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Published

2026-03-30

How to Cite

[1]
C. . Liu, K. . Fan, and J. . Chen, “A Conformal FDTD Algorithm with Distorted Grid Face Filtering for Enhanced Efficiency ”, ACES Journal, vol. 41, no. 03, pp. 216–224, Mar. 2026.

Issue

2026: Vol 41 Iss 3

Section

General Submission

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