Over the last 10 years, the group has conducted innovative research that has focused on developing a coherent Electromagnetic (EM) capability, with the particular aim of tackling large scale, complex and multiscale problems. The core of the research has been a broadband (time-domain) and unconditionally stable TLM method based on a tetrahedral discretisation mesh – Unstructured Transmission Line Modelling method (UTLM).
The UTLM uses three-dimensional Delaunay mesh for discretisation of the problem space. The combination of the 3D tetrahedral mesh and a time domain EM solver that is unconditionally stable is what makes the software unique in the world. High level of parallelisation makes the software uniquely placed to tackle broadband large-scale simulations in an accurate and stable manner.
The main benefits of the UTLM are:
- Smooth and improved discretisation
- Hybrid meshing – combining tetrahedral and cubic mesh as the most efficient computational discretisation.
- Unconditional stability
Added featured are:
The main elements to the UTLM software are:
Geometry Generator
The geometry generator allows the user to create complex 3D geometrical structures suitable for meshing and subsequent EM simulation. The code is delivered as a library of C++ codes and a main that provides a easy command line interface. The user writes their own code and recompile in order to generate new geometries. The code has been tested on Linux, Cyqwin and MinGW platforms.
The software builds structures starting from a small set of primitive objects (spheres, cubes etc) which are then combined into more complex objects using Boolean geometry operators (merge, intersection, minus, pass) and other manipulators such as stretching. Each object is represented as a closed triangulated surface. Below are some of the objects created using our geometry generator software.
Mesh Generation
Once a geometry a such as an aircraft body been captured, the problem must be sub-divided into small cells for the purposes of computation. Cells may be cubic, or much more flexibly, triangular and tetrahedral and the critical issues are the number, size, uniformity of these cells and who accurately they reflect the true geometry.
Our mesh generation software provides 100% Delaunay tetrahedralisations that are seamlessly integrated with cubically meshed regions to optimise subsequent simulation performance.
The software reads a number of bespoke and commercial CAD formats and is controlled through a Windows GUI and easily permits targeted mesh refinement to be introduced by the user.
The code runs on Linux platforms and is highly optimised for speed and memory performance.
We do not publish on mesh generation, so if this is of interest please contact us by email.
Solver
The time domain solver allows a variety sources to be introduced into a simulation that evaluates how electromagnetic fields, currents, voltages, wave scattering etc evolve in time. Sources and the associated observations, material models, surface treatments etc can be introduced via a flexible Windows GUI that when combined with the mesh of the structure, creates the overall model.
Advanced material models such as multilayer anisotropic CFC skins are available as well a s a sophisticated digital filter suite to provide in situ data processing.
The code incorporates a full facility to identify the “modes” of waveguide structures which can be used to extract S-parameters, provide sources and broadband perfectly terminated boundaries.
Various output formats include far field scatter patterns and Radar Cross Section calculations.
All outputs can be visualised in our Windows GUIs that provide the user with the usual zoon-focus-rotate features along with the ability to animate the evolution with time of for example surface currents.
The code is fully parallelised and we routinely run it over our 160 core commodity clusters equipped with a 1 TB of RAM.
Key Contacts
- Dr Ana Vukovic
- Prof Phillip Sewell