Developing multi-physics, multi-scale wave modelling on graphics cards
Project Description
The use of the time-explicit FE method for simulating ultrasound in many engineering components has been demonstrated to be accurate for propagation within metals, and the use graphics cards such as through software packages like Pogo (developed in the Imperial NDE group) enables the algorithm to be solved efficiently. The goal of this work is to improve the accuracy in more complex scenarios, where both multi-scale and multi-physics behaviour become important. An example of this is ultrasound within human tissue, where there are a wide range of scales from the body itself down to sub-cell structures, and with properties vary from liquid to solid (supporting shear and longitudinal waves) with variable complex anisotropy and periodic structures. The intention here is to develop an efficient integrated solution for simulating wave interaction with such structures. Development of multi-physics will enable more complex physical behaviour to be captured enabling greater understanding of various phenomena, such as the low speed shear wave (1-3m/s) seen in tissue and used for elastography (compared to the 1500m/s for the longitudinal wave of general interest). This also has applications in the emulsions and structures used in batteries, an important new application of ultrasound, to test battery integrity.
Existing background work
This will build upon the Pogo software package, which has been used for simulating ultrasound within NDE (Non-Destructive Evaluation) for over 10 years and is now used throughout the world in industry and academia.
Dr Huthwaite has extensive experience with a variety of approximations for simulating waves in different materials, including ray theory (eikonal equation) and Born approximation-type approaches, as well as developing the FE method on graphics cards. He has been involved in techniques to model complex solid media such as large-grained material, developing models of over 1 billion degrees of freedom. Some multi-scale work has been done in the broader research community, typically with small-scale evaluations to estimate homogenised properties, which are then used for larger simulations. Multi-physics approaches have also been utilised and are common in areas such as transduction where different phenomena need to be coupled, but integrating these with multi-scale techniques presents a new challenge.
Main objectives of the project
Deliver an efficient approach for accurate modelling of wave propagation through multiscale, multi-physics problems. Apply the method to propagation through complex structures, such as tissue, and ideally compare to experimental measurements.
Details of Software/Data Deliverables
The outcomes will be incorporated into the Pogo software package for application across a variety of areas including NDE, medicine and underwater ultrasound. Describe coding and data developments during the project. Specific techniques will need to be developed to code the method to achieve results without compromising GPU performance.
