What's New in PHOENICS
Document last revised: 13.03.13
Changes made between November 2011 and January 2013
Details about new changes to the VR Editor and solver are reported here.
1. The general trends
The "New Trends" of 2011 have continued with increased concentration,
momentum and practical effect.
In respect of concentration, attention is now focussed on three classes of PHOENICS user, namely:
- End users, who wish to have 'simulation engines' designed for their specific
closely-defined applications. These are the diners in the 'PHOENICS Restaurant', who choose
from the menu what suits their appetite; and who pay the bill at the end,
- Creative users, who provide the specialised packages which the end users employ.
They are the cooks who prepare the familiar dishes; and some of them are chefs who create
- Do-it-yourself users, who are content to use the long-established VR-Editor so as
to set up problems on their own.
Of the End-User class the following may be said:
- They are conceived to be specialists in their application area, and so able to recognise
and reject simulations which are obviously incorrect; but they are in no way required to be
CFD specialists. They rely on the package providers to supply all the guidance and protection
which they need; and to ensure that using the package is easy.
- Students and teachers of fluid mechanics and heat transfer fall into this category, Their
focus is on what is to be learned and taught about the various chapters of their subjects;
not on how PHOENICS happens to express their implications.
- End Users should however know enough about computational fluid dynamics to understand that
it deals in probabilities rather than certainties; and that its predictions become less and
less reliable the more are the phenomena in question complicated by turbulence, multi-phase
flow and chemical reaction.
For the do-it-yourself users, PHOENICS has been improved in various manners, an
overview of these changes are listed in the 2012 What's New report.
For example a 'sun object' has been introduced.
However, no fundamental reduction has been made in the VR-Editor's limitations. It remains
as a single-instance-run launcher; and it is still unable to assist its users to exploit the
full powers of the PHOENICS Input Language, PIL.
It is for the Creative-User class that the greatest new benefits have been provided,
- Special-application packages have now been given the formal status of Simulation Scenarios,
or SimScenes for short. These are both easier to create and simpler to use than the
PRELUDE-based Gateways which were emphasised in 2011.
- These can be supplied to customers either as specielly-ordered add-ons to standard PHOENICS
or as stand-alone single-purpose packages.
- Each has an easy-to-use menu, which is designed to assist a specific End-User group.
- Each SimScene is defined by a PQ1, i.e. Parameterised Q1, written in PIL, which
contains the new VREDIT=F entry, so enabling all the "protected-mode" saveXbegin and saveXend
statements to be dispensed with.
- Writing of PQ1s is aided by a new PQ1 editor which is copiously supplied with 'macros'
and 'line-completion' items which reduce the writer's labour and reduce his chance of making
mistakes. Moreover this editor is customisable, in the sense that users can add the macros
and line-completions which most suit them.
- Of great convenience is the 'multirun' facility which enables many runs to be performed,
with systematically varied input parameters, and their results to be easily compared.
- Also created, but not yet greatly used, is the multi-language SimScene capability. When
Japanese, Russian, Chinese and Arabic users recognise its existence, they will surely exploit
it with enthusiasm.
- Two new PIL commands have been added, namely WRITE( , ) and EXEC( , ). The former enables
PIL entries to instruct Satellite to write files with whatever content the PQ1-writer needs.
For example it can write PHOTON_USE files; and what it writes can be parameterised, so that,
for example, the 'use' file to which PHOTON responds already knows what are the values of
NX, NY, etcetera.
- The ShapeMaker program has been modified to enable it to accept instructions from files
as well as interactively. As a consequence, the creative-user PQ1 writer can now:
- use WRITE to define the instruction to Shapemaker which cause it to create some
- use EXEC to instruct ShapeMaker to read the file and create the object;
- place in the PQ1 the lines which cause Satellite to display the object and to tell
Earth how to react to it.
- In this manner a severe limitation of the past has been removed. Formerly, users were
restricted (as DIY ones still are) to using such objects as they could find in the sub-folders
beneath \phoenics\d_satell\d_object. Therefore, if they needed a hollow solid cyinder, they
had to create one for themselves by introducing a not-hollow solid cylinder and a
smaller-diameter concentric fluid-containing cylinder to represent its hollow inside.
Such contortions are no longer necessary.
In summary, it would be no exaggeration to state that PHOENICS underwent a radical change in
2012; and prospective not-yet-users may find that that these changes have increased its
Other developments during 2012
- PARSOL improvements, especially in relation to cylindrical-polar grids.
- Wind-farm related improvements, especially in relation of use of un-structured grids,
and of GCV rather than MIGAL for body-fitted-coordinate grids
Work in progress, 2012-2013
- Replacement of PARSOL with SPARSOL (i.e. Structured PARSOL) which allows
thin-plate objects to be simulated.
- Unificaton and speed-up of linear-equation solvers.
- Unification of treatment of VR (facet-described) and In-Form (parameterised)
- Creation of heat-exchanger-related SimScenes.
Changes made between September 2010 and December 2012
For more details about the following changes click
- Inlet objects have a vector arrow showing the direction of flow.
- Main Menu allows setting of domain edge boundary conditions.
Wall Yes - create a PLATE
object at this domain face. The name (for X) will be DOM_XMIN_W or DOM_XMAX_W
Open Yes - create an OUTLET
object at this domain face. The name (for X) will be DOM_XMIN_O or DOM_XMAX_O
Flow Yes - create an INLET
object at this domain face. The name (for X) will be DOM_XMIN_I or DOM_XMAX_I
Objects are created with default settings – the user must set any non-default values.
Existing PLATE, OUTLET or INLET objects (with any name) that cover a whole domain face
will be recognised and will set the flags on the dialog.
- Activation of transient restarts made easier.
On the ‘Time step settings’ dialog, set ‘First step number’ > 1 and a dialog will offer
to activate the restart.
All necessary file names will be deduced.
- Object names can be up to 12 characters long.
- The Q1 can be saved to a different name without saving all the output files
‘File – Save Q1 As...’.
- The dialog for starting parallel has been updated to allow more flexibility.
- The facilities for repairing and manipulating CAD data during and after import have
been improved with the introduction of the new DatMaker utility.
- Start-up dialog offers most recent set of results
- New function key F9 always loads most recent set of results.
- The domain can be mirrored in any direction.
- Vectors can be drawn as 3D arrows.
- Contours and vectors can be plotted on an arbitrary surface of any shape –
the ‘Plotting Surface’ object.
- Rotate to any position:
- Select the new object, right-click and select 'Surface contours'
- Or select 'Surface vectors'
- Contours have new options  Fill,  Lines and  Lines and fill.
These can be applied to contour planes, contours on surfaces of objects and contours on
Plotting Surface objects:-
- An extra selection mode has been added. Holding shift+cntrl when selecting an object on the
screen selects all objects under the cursor, not just the nearest. Objects have a
'Selectability' flag. Objects that obstruct others can be made 'unselectable'
(from the screen) so that those behind can be selected. The view centre can be set to the middle
of a selected object and the working directory is displayed in the status bar at the bottom of the
There have been many modifications to EARTH. A full double-precision version of the
EARTH solver is now available. In some cases this converges much better than the
standard single-precision version. This is especially true for transient cases where
the domain is huge and not much is happening. The price is doubling the memory requirement.
The normalised residuals displayed on the monitor screen have been a cause of wonder
and amazement for some time. The idea – to normalise the errors by the sums of sources
and fluxes – was good, but the implementation was suspect. Residual values of a
thousand % were common, and the normalised error increased as the number of cells increased.
PHOENICS-FLAIR users have the CONV_TABLE.CSV file which contains the errors normalised by
the inflow fluxes. The problem with the internal normalisation has been fixed, so that
the normalised residuals are now a much-improved reflection of the level of convergence.
|The old normalisation produced:
||The new normalisation produces:
|Whole-field residuals before solution at sweep 400
with resref values determined by EARTH & resfac=1.0E-06
|Whole-field residuals before solution at sweep 400
with resref values determined by EARTH & resfac=1.0E-06
||(res sum)/resref||(res sum)
||(res sum)/resref||(res sum)
The actual residual is almost the same, but the normalised value is very small and more like
that in CONV_TABLE.CSV.
There have been three modes of operation for the graphical convergence monitor:
- Spot value and residual;
- Maximum correction and sum of nett sources; or
- Maximum and minimum value in the field.
It has always been possible to switch mode during the run, but the graph only switched at
the moment of changing, so the previous values were not displayed. All monitoring values for
all three modes are now held, and when the mode is changed the entire graph is redrawn in the
new mode. It is possible to set a flag (Options, Solver Monitor Options) to have images of
all three modes saved at the end of a run.
Some further changes and bug fixes include:-
SUNLIGHT OBJECT Update
The SUNLIGHT feature was created in 2010 in response to the demand from users for a HeatIsle
module. The prototype for which is described
This has now been updated to improve its flexibility.
The preliminary version was accessed through the WIND object dialog, and had several limitations:
An updated version is now ready for release. The main improvements made are:-
No longer accessed through WIND, there is a separate SUN object.
The required inputs can be read from a standard EPW Weather Data File. The fields read
- The latitude was a user-input
- The direct solar radiation was a user-input
- There was no allowance for diffuse solar radiation
- Transient operation was very limited, with multiple WINDs being required.
A link to the EPW site is provided for easy download of weather data files.
The WIND object can take the wind speed and direction from the same weather file.
The transient operation has been improved.
The amount of incident solar radiation absorbed by each object in the scene can be set
by the user.
BLOCKAGE and PLATE objects have an extra ‘Solar absorption’ input box which allows the
absorption factor for that object to be set. For most substances the absorption will be 0.5
or greater. Bricks, weathered steel or marble can be up to 0.9. Polished metal surfaces can
be 0.1 – 0.2.
The user no longer has to ensure that objects are facetted in order for them to be picked
up by the illumination algorithm.
The illumination algorithm will detect PLATE objects as well as BLOCKAGEs
The following additional output variables can be activated directly from the SUN object
- Direct and diffuse solar radiation
- Air and ground temperature
These can be used to check the correct functioning of the illumination model.
Conditions can now be taken from a weather file and applied directly. Having created
a SUN object, open its attribute dialogue to use and configure a weather data file. The
default browser will open the Energy Plus site from where the weather data file can be
selected and downloaded [if you do not have a weather file, clicking on 'Start browser'
will enable you to download one]. Once selected, the data file can be loaded directly
into the VR Editor.
- The illumination flag LIT
- The potentially illuminated surface flag #SRF
- The TEM1 heat source per cell #QS1
- The total heat source per unit area #QS2
- The T3 heat source per cell (for IMMERSOL) #Q3
- The solar absorption factor #SOL
The WIND object can also use the weather data file
- The pre-attached data file is used, and the current data are shown
- The WIND object graphic shows the current North (blue) and wind (red) direction.
- In a transient case, the time-step setting dialog controls the time step size and number
of steps to run. The time of day at the start of the run is the time chosen from the
weather data file. The data values from the file are transmitted to EARTH, and at each
time step the solver interpolates between the data-file values to get the current inlet
values. The solar shading is updated at the start of each time step, and the current direct
and diffuse solar radiation values are interpolated from the weather data file. Animation
is available to show, for example, a 24-hour sequence.
- When a weather file is in use for a transient case, the external pressure and temperature
are updated at each time step from the weather file. This was done by updating the external
pressure at outflow boundaries. In practice, it turned out that changing the external pressure
can have unexpected consequences, for example creating inflows when the external pressure
rises. This has been addressed by keeping the external pressure at zero relative to the
reference pressure, PRESS0, and updating PRESS0 each time step.
- In addition, the reference density for buoyancy, BUOYD, is also updated each time step to
match the new external pressure and temperature. The transient behaviour is much improved
by these two measures.
- When a SUN object is active, the 'Solar absorption' factor of the WIND ground plane can
also be set. The 'Wind Amplification Factor' (local absolute velocity divided by reference
velocity) can be STOREd by a button-click on the WIND object attributes dialog.
DATMAKER and CAD conversion
The facilities for repairing and manipulating CAD data during and after import have
been improved . The new DatMaker utility can:
- Mend holes
- Ensure all facets point outwards
- Repair folded facets
- Split an object into separate bodies
- Merge objects
- Subtract objects
Often problems with geometry detection can be eased or removed by merging several touching or overlapping objects into one. The same applies to subtracting an air space from a surrounding blockage. DatMaker is now used by default when importing single or multiple CAD files, to translate the CAD to DAT format. The supported formats are, as before :-
|STL||-||Stereo lithography file available in many popular CAD programs as an
|DXF||-||Drawing Exchange Format File (AutoCAD)
|3DS||-||Autodesk 3ds Max
|WRL||-||Virtual Reality Modelling Language file
|DW||-||Files generated by DesignWorkshop from
|AC||-||Files generated by AC3D from
|IV||-||Files generated by Open Inventor
DatMaker can also be used to perform operations on objects already created in VR. Existing objects can be merged, split or subtracted. (1) Here there are 5 air blockages making a channel through a hidden solid; (2) then merged into one object; and (3) now subtracted from the solid leaving a channel.
A further utility already built into PHOENICS is called AC3D from Inivis. As well as creating shapes from scratch, AC3D can import a variety of additional formats that can be exported in the native .DAT format used by PHOENICS. Alternatively, products such as Okino NuGraph can also import, repair, convert and export a variety of formats, including the 3DS format readily accepted by PHOENICS.
|AC3D from Inivis a range of
||OKINO NuGraph supports:
HIGHLIGHTS from the previous update
Here follow some improvements made in the previous release which are worth mentioning again,
in case they have been missed. In the VR-Editor:-
- The ‘Object affects grid’ attribute has been split into the three coordinate directions.
- A long-standing error in the Auto-mesher has been corrected.
- The grid refinement stops when the ratio between the size of the last cell in one region
and the first in the next region falls below a set criterion.
- On the auto-mesh dialog, this was set as a fraction of the domain size, but was then
treated as an actual physical dimension when being compared to the cell sizes.
- This means that for large domains, the refinement process terminated earlier than expected.
- There is also a new option to set the minimum and initial cell sizes as physical
dimensions rather than fractions of the domain size.
In the EARTH solver of PHOENICS/FLAIR, the ‘Calculate link temperature’ and
‘Activation temperature’ settings for a SPRAY_HEAD object activates automatically the spray
when the activation temperature is reached. In previous versions, a message was written to
RESULT when the criterion was met, but the spray was not activated automatically. A table
file containing the calculated link temperatures at the end of each step is also produced.
For details of these previous updates Click here