Overview of Group Activities

Our group is focused on computational solutions to Maxwell’s equations, which describe electromagnetic phenomena, from zero frequency to terahertz frequencies. In addition, we have been developing multi-physics codes that couple physics such as semiconductor device physics, hysteresis of magnetic materials, and stress effects such as magnetostriction with Maxwell’s equations. The various codes we develop are based on differential-based solutions such as the Finite-Element Method (FEM) and the Discontinuous-Galerkin Finite-Element Time-Domain (DGFETD) method and integral solutions such as the Moment methods and the Nyström methods to Maxwell’s equations. In particular, we are implementing high-order methods that are parallelized for efficient solution on a high-performance cluster of extremely large-scale problems.

Primary problem areas we are researching include:

1. Magnetic signature modeling of ships that includes hysteretic magnetic materials, eddy currents, and magnetostriction.
2. Mesh-stable and frequency-stable discretizations of integral equation solutions to Maxwell’s equations.
3. Parallel, fast-direct solvers based on local-global solutions of extremely large matrix equations.
4. DGFETD modeling of terahertz-band photoconductive antennas by solution of the coupled Maxwell/Semiconductor equations.
5. DGFETD modeling of dispersive materials.

Magneto-Stress Analysis

Description: Analysis of the stress effects on the magnetic signature of naval vessels. A Nyström discretization of the quasi-magnetostatic integral equation was implemented. Models for stress effects on a magnetic material were developed and incorporated into the integral equation discretization. The software was developed in-house.

Students

Robert A. Pfeiffer, Grad
Victoria Zachman, Grad

Jordon N Blackburn, Added 08/31/2021

Collaborators

S. Gedney (PI)
J. Young (Co-PI)
R. Adams (Co-PI)

Software

Additional Software Required: Intel C++ compiler, Intel Fortran compiler, Intel Math Kernel Library, Intel MPI library

Large Scale Topside Electromagnetic Modeling

Description: Fast solution techniques for large-scale electromagnetic problems were investigated. In particular, formulations were sought that were efficient and accurate for arbitrary frequency and mesh density. Matrix compression techniques based on the multi-level simply sparse method were developed and a fast-direct solver based on local-global solutions was applied.

Students

J. Cheng (Post-Doc)
N. Hendijani (Ph.D. Student)

Collaborators

R. Adams (PI)
J. Young (Co-PI)
S. Gedney (Co-PI)

Software

Additional Software Required: Intel C++ compiler, Intel Fortran compiler, Intel Math Kernel Library, Intel MPI library.

Photoconductive Antennas for Terahertz Spectroscopy and Imaging

Description: Software based on the DGFETD method was developed to analyze and design photoconductive antennas in the terahertz band. The DGFETD simulation included both electromagnetic effects and semiconductor device effects as well as accounted for a femtosecond pulsed-laser excitation. The software was parallelized for use on a cluster.

Collaborators

J. Young (PI)
S. Gedney (Co-PI)

Software

Additional Software Required: Intel C++ compiler, Intel Math Kernel Library, Intel MPI library.

Closed-Loop Degaussing of Surface Vessel

Description: Techniques were investigated to extract the state of a hysteretic magnetic material based on near-field measurements of the magnetic field. The effectiveness of using the extracted state to evaluate the magnetic signature for controlling degaussing coils was considered. Magnetic signature evaluation and magnetic material state extraction was based on a Nyström discretization of the quasi-magnetostatic integral equation.

Collaborators

S. Gedney (PI)
J. Young (Co-PI)
R. Adams (Co-PI)

Software

Additional Software Required: Intel C++ compiler, Intel Fortran compiler, Intel Math Kernel Library, Intel MPI library.

Non-Uniform Loading of Surface Vessels

Description: Effects of non-uniform loads such as wind and waves on the magnetic signatures of ships is being investigated. Models for wind and wave pressure are being developed for use in the commercial finite-element analysis code LS/Dyna and incorporated into an in-house developed quasi-magnetostatic integral equation solver. Magnetic materials are affected by stress through magnetostriction effects.

Collaborators

S. Gedney (PI)
J. Young (Co-PI)
R. Adams (Co-PI)
J. Wenk (Co-PI)

Software

Additional Software Required: Intel C++ compiler, Intel Fortran compiler, Intel Math Kernel Library, Intel MPI library?, LS/Dyna? Finite Element Analysis

Efficient Linear Solvers for Gemeni

Description: The purpose of this project is to integrate the sparse linear solution library, MFDlib, developed at the University of Kentucky, with NASA’s primary computational electromagnetics tool, Gemini. MFDlib is a library of data sparse methods for efficient filling, factorization, and solution of large electromagnetic problems formulated using integral equation methods. The integration of MFDlib with Gemini will enable NASA to solve large-scale problems that are currently beyond the capacity of NASA’s existing tools and facilities. Gemini is a Fortran code developed by NASA’s Johson Space Center. All other software is developed by the UKY team.

Students

Buxton Johnson, MS

Collaborators

Robert J Adams, PI
John C Young, Co-PI

Software

Additional Software Required: Intel Fortran compiler, Intel Math Kernel Library, Intel MPI library

Publications

• J. C. Young, R. J. Adams, and S. D. Gedney, "A Parallel Implementation of an OL-LOGOS Sparse Direct Solver," 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, IF346.40, Memphis, TN, July 6-11, 2014.
• Nastaran Hendijani, R. J. Adams, and J. C. Young, "High-order Nyström Implementation of an Augmented Volume Integral Equation," 2014 IEEE
International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, IF343.15, Memphis, TN, July 6-11, 2014.
• J. Cheng, R. J. Adams, and J. C. Young, "Nyström Discretization of an Augmented Electric Field Integral Equation with Magnetic Field Constraint," 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, IF343.14, Memphis, TN, July 6-11, 2014.
• J.C. Young, S.D. Gedney, and R.J. Adams, “Hysteresis Modeling with a Nystrom Discretization of the Quasi-Magnetostatic Volume Integral Equation,” IEEE International Symposium on Antennas and Propagation and CNC/USNC/URSI National Radio Science Meeting, #307.8, Orlando, FL, July 2013.
• J.C. Young, S.D. Gedney, and R.J. Adams, "Eddy Current Analysis using a Nyström-Discretization of the Volume Integral Equations," IEEE Trans. Magnetics., vol. 49, no. 12, pp. 5675-5681, Dec. 2013.
• J.C. Young, D. Boyd, S.D. Gedney, J. Liu, and T. Suzuki, “A Comparison of Measured and Computed Data for Photoconductive Antennas,” IEEE International Symposium on Antennas and Propagation and CNC/USNC/URSI National Radio Science Meeting, #406.8, Orlando, FL, July 2013.
• J.C. Young, S.D. Gedney, R.J. Adams, “A High-Order Nyström-Based Volume Integral Equation for Quasi-Magnetostatic Problems with Eddy Currents,” Applied Computational Electromagnetics Society Conference, Columbus, OH, April 2012.
• J.C. Young, S.D. Gedney, and R.J. Adams, "Quasi-Mixed-Order Prism Basis Functions for Nyström-Based Volume Integral Equations ," IEEE Trans. Magnetics., vol. 48, no.10, pp. 2560-2566, Oct. 2012.
• J.C. Young, S.D. Gedney, and R.J. Adams, “A Nystrom Solution of the Quasi-Magnetostatic Volume Integral Equation for Eddy Current Analysis,” IEEE International Symposium on Antennas and Propagation and CNC/USNC/URSI National Radio Science Meeting, #263.4, Chicago, IL, July 2012.• J.C. Young, Y. Xu, R.J. Adams, and S.D. Gedney, "High-Order Nystrom Implementation of an Augmented Electric Field Integral Equation," IEEE Antennas and Wireless Propagation Letters," vol. 11, pp. 846-849, 2012.
• J.C. Young, D. Boyd, S.D. Gedney, and T. Suzuki, "A DGFETD Analysis of a Terahertz-Band Photoconductive Dipole Antenna,” 2012 IEEE International Symposium on Antennas and Propagation and CNC/USNC/URSI National Radio Science Meeting, #152.2, Chicago, IL, July 2012.
• J.C. Young and S. Gedney, "A Locally Correct Nyström Formulation for the Magnetostatic Volume Integral Equation," IEEE Trans. Magnetics., vol. 47, no. 9, pp. 2163-2170, Sept. 2011.
• S.D. Gedney, J.C. Young, X. Xin, R.J. Adams, "LOGOS Solution of a Locally Corrected Nystrom Formulation for the Magnetostatic Volume Integral Equation,"IEEE AP-S International Symposium and USNC/URSI National Radio Science Meeting, #IF220.2, Toronto, Canada, July 2010.

Publications

2014

J. C. Young, R. J. Adams, and S. D. Gedney, "A Parallel Implementation of an OL-LOGOS Sparse Direct Solver," 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, IF346.40, Memphis, TN, July 6-11, 2014.
Nastaran Hendijani, R. J. Adams, and J. C. Young, "High-order Nyström Implementation of an Augmented Volume Integral Equation," 2014 IEEE
International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, IF343.15, Memphis, TN, July 6-11, 2014.
J. Cheng, R. J. Adams, and J. C. Young, "Nyström Discretization of an Augmented Electric Field Integral Equation with Magnetic Field Constraint," 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, IF343.14, Memphis, TN, July 6-11, 2014.

Grants

Young, John KSEF-148-502-11-283 KSEF RDE: Photoconductive Antennas for Terahertz Spectroscopy and Imaging KY Science and Technology Co Inc 7/1/2011 - 6/30/2014 $66,479

Office of Naval Research, ONR Award# N00014-11-1-0584, 6/1/11-5/31/13, $397K
Office of Naval Research, ONR Award# N00014-11-1-0625, 7/1/11-6/30/14, $397K
Kentucky Science and Engineering Foundation, #KSEF-2489-RDE-014, 7/1/11-6/30/14, $90K
Office of Naval Research, ONR Award# N00014-13-1-0414,26/1/13-12/31/13, $50K
Office of Naval Research, ONR Award# N00014-14-1-0161, 1/1/14-12/31/16, $400K
NASA-KY and Office of Naval Research, RIDG-14-017, 6/1/14-5/31/15, $40K, R. Adams (PI), J. Young (Co-PI), B. Johnson (MS student).