Efficient Computation of 3D Engineered (Anisotropic) Materials
Lead Research Organisation:
University of Nottingham
Department Name: Faculty of Engineering
Abstract
RESEARCH OVERVIEW AND OBJECTIVES
Interest in the modelling of complex electromagnetic phenomena has grown significantly in recent years. This has largely been influenced by two factors: increasingly more powerful computers, and advancements in solver algorithms. As such, the modelling capabilities of time domain techniques, such as the transmission line modelling methods (TLM), are continually being expanded to enable an efficient representation of three dimensional materials with complex properties.
This work focuses on the TLM algorithm and its derivative, the unstructured transmission line modelling (UTLM) method. The objectives of the project can be divided into two phases, namely the shorter intermediate aims and longer term goal which are given below:
Short/Intermediate aim is to:
1. To investigate the various perfectly matched layer (PML) formulations in TLM with the aim of improving the issues relating to the inferior reflection performance and late-time instabilities.
2. In addition to this, a formulation that integrates the PML technique into the UTLM algorithm will also be investigated.
Long term aim is to:
3. Explore the opportunities presented by coordinate transformations as an approach to devise a UTLM formulation for bulk anisotropic materials and thus an original PML for tetrahedral TLM grids.
METHODOLOGY / APPROACH
The proposed methodology to achieve the short/long term goal involves:
1. Exploring coordinate transformations and its equivalence with material parameters. Particularly, in the case of the stretched based coordinate (SCB) PML interpretation.
2. An implementation of the SCB PML that follows a TLM philosophy will be formulated for the structured and unstructured TLM methods.
3. An hybrid approach to implementing the PML in UTLM will also be taken which involves employing an unstructured mesh in the computational domain and a structured mesh in the PML region.
NOVELTY
1. To date, all existing TLM-PML formulations have demonstrated weak stability and inferior performance to their finite-difference time domain counterpart. Therefore, any improvement on these issues will prove novel.
2. To date, the PML has not been demonstrated in an original tetrahedral TLM mesh. Achieving this will be a major advance in the field and thus demonstrates novelty.
3. To date, the PML has not been demonstrated in a UTLM mesh via an hybrid approach. Therefore, simply introducing the PML into UTLM will be a major contribution to the field, seeing that the truncation methods currently employed are computationally inefficient in comparison to the PML.
Interest in the modelling of complex electromagnetic phenomena has grown significantly in recent years. This has largely been influenced by two factors: increasingly more powerful computers, and advancements in solver algorithms. As such, the modelling capabilities of time domain techniques, such as the transmission line modelling methods (TLM), are continually being expanded to enable an efficient representation of three dimensional materials with complex properties.
This work focuses on the TLM algorithm and its derivative, the unstructured transmission line modelling (UTLM) method. The objectives of the project can be divided into two phases, namely the shorter intermediate aims and longer term goal which are given below:
Short/Intermediate aim is to:
1. To investigate the various perfectly matched layer (PML) formulations in TLM with the aim of improving the issues relating to the inferior reflection performance and late-time instabilities.
2. In addition to this, a formulation that integrates the PML technique into the UTLM algorithm will also be investigated.
Long term aim is to:
3. Explore the opportunities presented by coordinate transformations as an approach to devise a UTLM formulation for bulk anisotropic materials and thus an original PML for tetrahedral TLM grids.
METHODOLOGY / APPROACH
The proposed methodology to achieve the short/long term goal involves:
1. Exploring coordinate transformations and its equivalence with material parameters. Particularly, in the case of the stretched based coordinate (SCB) PML interpretation.
2. An implementation of the SCB PML that follows a TLM philosophy will be formulated for the structured and unstructured TLM methods.
3. An hybrid approach to implementing the PML in UTLM will also be taken which involves employing an unstructured mesh in the computational domain and a structured mesh in the PML region.
NOVELTY
1. To date, all existing TLM-PML formulations have demonstrated weak stability and inferior performance to their finite-difference time domain counterpart. Therefore, any improvement on these issues will prove novel.
2. To date, the PML has not been demonstrated in an original tetrahedral TLM mesh. Achieving this will be a major advance in the field and thus demonstrates novelty.
3. To date, the PML has not been demonstrated in a UTLM mesh via an hybrid approach. Therefore, simply introducing the PML into UTLM will be a major contribution to the field, seeing that the truncation methods currently employed are computationally inefficient in comparison to the PML.
Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N50970X/1 | 01/10/2016 | 30/09/2021 | |||
| 1904673 | Studentship | EP/N50970X/1 | 01/07/2017 | 24/04/2021 | Jomiloju Odeyemi |
| Description | The PML is widely accepted as the superior absorbing boundary technique and has become a prevalent feature in electromagnetic simulation packages. However, the challenge of developing an efficient and numerically stable TLM-PML formulation is also very well identified amongst TLM researchers. Hence, only a handful of implementations have been reported to date. In light of the huge benefits attainable, we implement, for the first time, a stretched coordinate PML suitable for terminating TLM grids for which we UNCONDITIONAL STABILITY is demonstrated. It is generally known that the PML performance is sensitive to the different discretization schemes employed. For this reason careful considerations must be made on the particular nature of the numerical method for which the PML is to be employed. Our hope through this work is to re-generate interest amongst TLM researchers towards the development of effective PML implementations. |
| Exploitation Route | This research delivers an effective ABSORBING BOUNDARY CONDITION suitable for TLM simulations. The benefits of such a contribution are: 1) more accurate therefore reliable data can be obtained. 2) stable for all test cases 3) significant saving in computational expense i.e. less memory usage and faster simulations |
| Sectors | Aerospace, Defence and Marine,Electronics,Other |
| URL | https://www.researchgate.net/profile/Jomiloju_Odeyemi |
| Description | Conference presentation |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | presented research findings at a conference. |
| Year(s) Of Engagement Activity | 2019 |