Any design project that involves the interaction of a component
with gases, liquids or vapours involves a lengthy evaluation programme.
A classic example is the testing of an aerodynamic structure in
a wind tunnel. The process is time consuming and expensive, which
is why so many engineering companies are turning to computer aided
engineering techniques, such as computational fluid dynamics (CFD)
to streamline the process (no pun intended). I've been taking a
look at what the CFD market has to offer.
Fluent (www.fluent.com) has just released version 2 of its FloWizard
tool (www.flowizard.com), designed for people with no specialist
CFD knowledge. Version 2 has an option called 'Rsolve', which offers
a secure, internet based, pay-as-you-go, low-cost CFD service that
you can dip into as and when you need it. For £4,000, you
get 300 CPU hours, and if you need any more, the average price
is just £3 per extra CPU hour. During a session, the user
has only to set up the problem to be modelled using a wizard based
approach - the meshing is automatic. You don't get a solver with
Rsolve; instead, the model is sent to Fluent's supercomputers for
processing via a secure web link, and the result returned to the
user.
The latest version (10.0) of the Ansys (www.ansys.com) simulation
environment includes 'coupled physics' technologies, such as advanced
fluid/structure interaction (FSI), which allows transient or steady
state analysis of fluid/structure problems with moving or deforming
geometries. Examples include realistic elastic artery modelling
for stent design or the wind loading of large structures. Ansys
and CAD specialist, Vistagy (www.vistagy.com) recently announced
a partnership to integrate the latter's FiberSIM composite design
software with the Ansys solver, to promote concurrent engineering
of composite structures. The integration is available in Ansys
10.0 and FiberSIM 3.5 or higher.
CFD is apparently the fastest growing CAE application in the automotive
industry, and its most popular CFD solver is Star-CD from CD-Adapco
(www.cd-adapco.com). Released earlier this year, the Windows version
of Star-CD v3.24 has many features aimed at the engine modelling
community, including a three-zone, extended coherent flame model,
combustion modelling tool. This general-purpose model is capable
of simulating combustion processes within petrol, diesel and hybrid
engine concepts.
Also released earlier this year, Exa's (www.exa.com) PowerFLOW
v3.5 offers rotating geometry simulation ideally suited to fan
and propeller design analysis, new fan model physics and a complete
new set of project control applications. Exa's PowerVIZ visualisation
package has also been updated; you can now view multiple projects
simultaneously, which makes it easy to compare one with another.
This summer, Blue Ridge Numerics (www.cfdesign.com) released CFDesign
v8.0 (www.cfdesign.com/v8), which simplifies access to a suite
of analysis options. The Motion Module, for example, makes quick
work of flow-driven motion analysis projects involving sliding
vane pump motion, as well as nutating (nodding), orbital and combinations
of angular and linear motion.
Nika's (www.nika.biz) engineering fluid dynamics (EFD) family
is now in version 6.0. This group of products includes EFD.Lab,
EFD.V5 for Catia v5 and EFD.Pro for Pro/Engineer Wildfire. Version
6.0 offers new physical models for analysing more complicated designs,
automatic interfaces to finite element modelling programs as well
as a new postprocessor for results visualisation. EFD version 6.0
can be used to analyse laminar and turbulent flows, heat transfer
and species transport for steady state and transient flow regimes.
Other products to check out include CFDStudio from Analytical & Computational
Research (www.acricfd.com), which is largely written in Java, and
the Windows based Flownex v6.7 (www.flownex.com), which numbers
sophisticated heat transfer solvers among its many other functions.
The OpenFOAM (open field operation and manipulation) CFD toolbox
(www.opencfd.co.uk/openfoam) is an interesting one. This is open
not just in terms of the source code, but also in its structure
and hierarchical design, so its solvers, utilities and libraries
are fully extendable. You can submit your own solvers, which are
subject to testing and validation by other users, so, in effect,
the software grows organically.
Postprocessing CFD data can be a time-consuming and resource-hungry
task, so I'll conclude by mentioning an option that many CFD users
have taken: using a separate postprocessing package so they don't
have to take up expensive CFD software time for crunching the data.
Tecplot (www.tecplot.co.uk) is one of the most popular choices
here; a highly capable data analysis, visualisation and animation
package that was originally designed for postprocessing CFD data
and still excels at this task. At a fraction of the price of dedicated
CFD software, Tecplot will read in data from packages such as Fluent
and Ansys, perform a very wide range of plotting and analysis tasks,
and view and compare results from other CFD solvers and experimental
data. Together with its CFD Analyser add-in, Tecplot delivers a
powerful CFD solver that is adept at extracting and processing
the critical information.
Dr Know's recommended download is Tecplot 10.4 Windows Demo -
download yours today.