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By Nicole M. Diana, FLUENT Product Market Manager
- Multiphase flow
- Dynamic mesh
- Rotating equipment
- Reacting flow
- Heat transfer and phase change
- Other enhancements
The release of FLUENT 6.1 is planned for the beginning of 2003. This version
is packed with many exciting new features and capabilities in several
focus areas, such as multiphase flow, dynamic mesh, rotating equipment,
reacting flow, and heat transfer and phase change. The release is the
result of a planning, development, and testing process in which specific
industrial applications are targeted for each new feature release. Clients
are interviewed to identify requirements and provide relevant test cases.
The targeted applications are subjected to a matrix of industrial-strength
test cases and three levels of progressively simpler cases. The industrial-strength
test cases must be passed in order for the targeted functionality to be
included in a release. Target applications for FLUENT 6.1 include: bubble
column reactors, fluidized bed reactors, packed bed reactors, surface
reactions in CVD reactors, in-cylinder flows, store separation and missile
launch, turbomachinery, underhood flows, and fuel injector pumps. Some
of the highlights of the new functionality are presented below.
Liquid volume fraction in a boiling simulation in which a column of water
is exposed to a heat source at the center of its base
Multiphase flow
The Eulerian multiphase model has
been extended to allow for heat and
mass transfer. Mass transfer can also
be included with VOF simulations. The
mixture model can now handle compressibility
in one phase, and several
standard drag laws have been added.
The discrete phase spray models can
now be used for transient as well as
steady-state analysis, and particles can
interact with both moving and sliding
zones. A new spray/wall impingement
model has been implemented that allows
for tangential droplet motion that can
arise from spray-wall interaction.
Dynamic mesh
Offered as a beta capability in FLUENT 6.0, the dynamic mesh model will
be officially released in FLUENT 6.1, with parallel functionality fully
supported. The novel approach used by this model requires the user to
specify only the initial mesh and boundary conditions for the moving wall(s).
The solver automatically generates all subsequent changes in the mesh
with each time step, using one or more of three available algorithms.
(See the article on page 5 for more details.)
Deposition of gallium arsenide in a vertical rotating disc reactor
Courtesy of EMCORE Corp.
Rotating equipment
For turbomachinery and rotating equipment simulations, a sliding mesh
preview tool has been provided to help determine if the mesh is valid
prior to launching a calculation. A mass flow outlet is now available,
and an enthalpy conservation option has been added to the mixing plane
model. For modeling real gases, a custom real gas model can be specified
through a user-defined function, and a template for the Redlich-Kwong
equation of state is also available. Turbomachineryspecific post-processing
tools have been expanded to address multistage problems.
Contours of vapor volume fraction for a 2D hydrofoil with Cavitation Number
0.91
Comparison of computed (blue line) and experimental (red circles) pressure
variation on the suction side of the 2D hydrofoil shown above
View factor calculation time (min) for a typical automotive underhood
simulation illustrates the surface-to-surface radiation model enhancements
in FLUENT 6.1
Reacting flow
For simulations involving surface reactions,
site species and bulk species are now distinguished
from one another, allowing for
multi-step surface reactions with deposition and
etching.
The porous media model has also been
enhanced to better handle chemically reacting
flows, typical of packed bed reactors. The
actual physical (interstitial) velocities in porous
media are now computed in addition to the
superficial velocities, to better account for the
effects of fluid acceleration. Chemical reactions
can be limited to individual zones and can be
disabled in certain zones, if desired. This is helpful
for modeling a reactor that contains a catalyst
region. Surface reactions can also now
be specified on walls adjacent to porous zones.
Also new is the composition PDF transport
model, implemented through a collaboration
with Professor Stephen Pope of Cornell. It provides
an accurate turbulence-chemistry interaction
model for real finite-rate chemistry in
turbulent flames.
Heat transfer and phase change
A partial enclosure option has been added
to the surface-to-surface radiation model that
allows portions of the geometry that are not
important for the radiative exchange calculation
to be ignored. In addition, the view factor solver
has been upgraded to a new version of Chaparral.
These two improvements significantly reduce
the CPU and memory requirements for the
view-factor calculation. A new, robust cavitation
model that can handle highly cavitating
flows has been added that accurately predicts
the pressure profile, even for very high pressure
conditions. A new heat exchanger model
has also been implemented.
Other enhancements
There are several solver-related enhancements.
A new gradient calculation scheme can
be selected that may result in more accurate
predictions on all meshes, but particularly on
unstructured meshes. Other new features include
fully automatic mesh refinement, the ability
to run DPM simulations on distributed memory
systems, and the ability to read cases with
non-conformal and sliding interfaces directly
into the parallel solver without encapsulation.
The new detached eddy simulation (DES)
model, which uses LES in the core turbulent
region and RANS in the wall-dominated region,
is a practical alternative to LES simulations for
high Reynolds number external aerodynamic
flows, since it is able to capture the physics
in an affordable manner. The V2F model from
Cascade Technologies is now embedded and
available for an additional fee. This four-equation
turbulence model is well-suited for low
Re number flows.
Additional new features in FLUENT 6.1 include
the ability to couple the WAVE engine simulation
code with FLUENT, a built-in capability to
compute discrete Fourier transforms of time series
data, and the ability to automatically build compiled
UDF libraries at the push of a button. In
addition to the UDF-based acoustics module that
was released in July, FLUENT 6.1 includes two
other UDF-based add-on modules: a magnetohydrodynamics
model and a continuous fiber
model. All three modules will be included on the
FLUENT 6.1 CDs. License keys will be needed
to access the magnetohydrodynamics and continuous
fiber modules; contact your local Fluent
office for more details.
This is only a sampling of the capabilities
that will be delivered in FLUENT 6.1. For more
details, review the release notes that are posted
on the User Services Center. At Fluent, we
are all very excited about the expanding range
of applications that can be addressed with the
FLUENT 6 platform.
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