Taking to the air
Computational fluid dynamics (CFD) enables the modelling of the dynamics of fluid flow — fluids being any gas or liquid. It creates an accurate prediction of detailed fluid dynamics, including fluid flow behaviour, heat transfer, phase change, chemical reactions, mechanical movement and the stresses on related solid structures.
“You take a real system, such as an aircraft, and use sophisticated maths to describe it. This creates a three dimensional representation with details like how fluid moves within fuel tanks, how the structure will respond and what stresses you see as a result,” explains Professor Arnaud Malan, founder and head of Elemental Numerics and a professor at the University of Cape Town’s (UCT) department of mechanical engineering.
CFD allows for accuracy when investigating an existing product or designing a virtual prototype for industries including aeronautics, space, biotechnology and energy provision.
This detailed modelling means there is potential for dramatic increases in safety and decreases in cost, as well as the ability to get a product to market quicker. “You can get up to 90% of the final design without building a single thing,” says Malan. He notes that CFD modelling in the aerospace industry has reduced prototyping costs by more than 100 times.
Malan is the primary developer of Elemental, the first all South African CFD code (or software). It is a next generation technology and has stirred up significant international interest, attracting overseas research funding of more than R8-million to date from companies such as Airbus and Airbus Defence and Space.
CFD software is a competitive market, dominated by four codes, with large revenue streams and immense growth potential. Malan says that currently international license fee revenues are estimated at an annual R5.6-billion.
So what makes the Elemental code different? “Existing commercial CFD codes are typically composed of separate modules to simulate different physics,” says Malan. “However, many real-life systems are multi-disciplinary. For example, aircraft and spacecraft are composed of a fluid and a structure, with the latter containing large amounts of liquid fuel. All of these interact as a whole.”
Elemental is multi-disciplinary in form and function, covering everything in a single code. This allows for a significant increase in efficiency and the type of things that can be modelled.
“To achieve this requires re-engineering not only the manner in which the code is structured, but the mathematics employed to describe each aspect. All complement each other, resulting in a fast and versatile multi-physics modelling tool,” says Malan.
Elemental is composed of less than 100 000 lines of code. The modular and flexible code means that maintenance is easy and customisation can occur.
“It has exceptional speed and accuracy and uses state-of-the-art parallel solvers [concurrent computational calculations], outperforming commercial codes,” says Malan.
He has numerous international evaluations to back up his statements. Airbus, the large passenger aircraft manufacturer, called the code “scientifically innovative while outperforming competing codes by a significant margin, particularly in terms of accuracy”.
Reaching new heights
Many of the Elemental advances have been published in scientific journals. The advances include breaking from traditional programming norms to allow for computation speed and the ability to customise software. The focus on one usually compromises the other.
The four codes dominating the market typically involve large teams of 80 people or more. Elemental’s multi-disciplinary approach translates into small teams of about three people.
This has a significant impact on reducing development cost and improving speed to market. With the Elemental code reaching maturity for certain applications, Malan, in collaboration with UCT, has created a new company, Elemental Numerics. The business will consult locally and internationally, as well as provide software under license.
This supplement has been paid for by the Mail & Guardian’s advertisers. Contents and photographs were supplied and approved by the NSTF.