Global automaker Ford has used
an innovative combustion modelling tool for the development of its new EcoBlue
range of high-efficiency diesel engines. The Converge CFD software package from
Convergent Science has been used by the Ford engineers to develop the new
2-litre EcoBlue diesel engines available in the Ford Transit.
Convergent Science is a global
leader in computational fluid dynamics (CFD) software. Its customers include
leading automotive and commercial vehicle manufacturers, tier one suppliers and
professional motorsport teams. Its flagship product, Converge, includes
groundbreaking technology that eliminates the user-defined mesh, fully couples
the automated mesh and the solver at runtime and automatically refines the mesh
when and where it is needed. Converge is revolutionising the CFD industry and
shifting the paradigm towards predictive CFD.
“The use of Converge has
allowed us to run high quality in-cylinder CFD simulations,” explained Dr
Werner Willems, Ford technical specialist for combustion systems, adding that “We
used Converge to refine a number of features on the EcoBlue, including the
shape of the combustion chamber, the piston bowl geometry and the fuel
In particular, Dr Willems and
his colleagues used the package during the development of the EcoBlue’s
innovative mirror-image intake ports. In a first for Ford, the symmetrical
design of the integrated inlet manifold causes the air going to cylinders one
and two to swirl clockwise, while the supply to cylinders three and four swirls
“The two sets of ports are
essentially mirror images of each other,” explained Dr Willems. “When you have
a lot of variation between the airflow you’re always focusing on getting the
weakest cylinder to work properly, which means the others are being held back.
Our mirrored port design improves the distribution of air between the
cylinders, which reduces emissions and fuel consumption,” he noted.
This contributes to the
EcoBlue’s impressive environmental credentials, which include a 13 per cent
reduction in fuel economy compared to its predecessor, as well as significant
reductions in tailpipe emissions.
CFD studies are a powerful tool
in engine development, but they have traditionally been a time-consuming and
complex process. Converge, however, reduces the amount of manual input required
by automating the meshing process carried out before the simulation.
What’s more, it uses a function
known as Adaptive Mesh Refinement (AMR) to regenerate the grid at each
time-step, re-structuring it to accommodate changes in geometry or activity.
That means that events such as valve opening and piston motion can be modelled
without stretching or skewing the mesh, which would incur so-called deformation
errors. More importantly, the AMR function is fully coupled with the flow and
chemistry solvers, so it can automatically vary the mesh density across the
model. By applying a denser mesh in more critical areas but reducing the cell
count elsewhere it can dramatically improve the speed-to-accuracy ratio of the
Ford engineers are now
pressing ahead with development of the EcoBlue range, which will shortly expand
to include passenger car variants. Simulation tools such as Converge look set
to play a major part in this work, as the company continues to deliver improved
fuel economy and reduced emissions.
Source: Ford Motor Company