Encyclopaedia Index

Highlights of PHOENICS-3.4

  1. In-Form: data-input via formulae in Q1
  2. Shape-Maker: how to create the objects you need
  3. The PHOENICS Manager
  4. DBOS: the sporty "second car"
  5. MIGAL: solution speed-up for large problems
  6. Goal-seeker: the input optimiser.
  7. VR-enhancements: to editor and viewer
  8. PARSOL: striding ahead
  9. Parallel: 2-processor PCs go twice as fast as one

1. In-Form

PHOENICS was the first CFD code to allow users access to Fortran sub-routines which they could edit.

For those preferring just to express their wishes by formulae in the Q1, CHAM created "PLANT" which turned the formulae into accurate Fortran, compiled it, re-built the EARTH executable, and carried out the simulation.

PHOENICS 3.3 added a "PLANT-menu" to make formula-writing easy. However, a compiler and a re-compilable version of PHOENICS, were still needed; and they cost.

The In-Form feature of PHOENICS-3.4 does what PLANT could do, and more, but without Fortran, compilation, re-building or cost.

In-Form has enormously increased the simulation capabilities of PHOENICS.
For further information, click here.

2. Shape-Maker

Since the beginning of VR, PHOENICS has been supplied with a warehouseful of objects (described by .dat files) which users could employ in their "virtual worlds". But there were never enough; and users had to turn to solid-modelling packages, or to home-made Fortran programs, to create what they wanted.

No longer; for PHOENICS-3.4 contains a stand-alone Shape-Maker program whch enables users to create objects, and to see them as soon as they are created.

The VR-GEOM program of version 3.3 was a step on the road; but it had to call on the VR-Editor to display the object. ShapeMaker handles the display on its own.

For further information, click here.

3. Management by Buttons

PHOENICS-3.4 provides a radically new means of activating PHOENICS modules: the PHOENICS Manager.

This offers window-panels containing large labelled buttons, with "hover-help" to describe their functions. Red buttons elicit information; grey buttons intitate actions; and green buttons bring new panels to the screen.

Consequently, there is no longer any need to remember, and then key in correctly any of the numerous PHOENICS commands. Just press the button!

Moreover, the Manager is very easily customisable. Users have only to add sub-directories to the tree, and to place in each a few-line buttons.txt files; then whatever display or action they desired is "buttoned-up".

For further information,

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click here

4. DBOS: the sporty "second car"

When PHOENICS for PCs first became popular, the preferred compiler was ftn77, marketed by Salford Software, which used Salford's DBOS memory management system.

Although PC PHOENICS has been supplied in recent years with Digital (now Compaq) Fortran compilers, some users still hanker after the speed of compilation, larger fonts, and general sturdiness of the earlier product.

PHOENICS-3.4 is therefore now been supplied in two versions, Digital/Compaq, and Salford/DBOS; and it is recommended that whoever wants to enjoy the different advantages of both should order both. The former has the better graphics; the latter has better text, but will not work with NT.

If PHOENICS-3.4 has already been installed on your machine, click here to see the commands which activate the Salford/Dbos executables.

5. MIGAL: solution speed-up for large problems

The larger the grid size the longer the computer time, as all CFD users are aware; and it is also known that multi-grid solvers can significantly limit the increase.

That is why CHAM and Michel Ferry R&D have collaborated to attach the latter's MIGAL multi-grid solver to PHOENICS.

MIGAL has been demonstrated, for large problems, to effect very great time reductions.

6. Goal-seeker: the input optimiser

PHOENICS-3.4 is being delivered with a new "goal-seeking" feature, which enables so called "inverse problems to be solved, such as the search for the constants in a formula which will best fit prescribed experimental data.

What happens is that PHOENICS performs "multi-runs", again and again (for example 1000 or more times). At the end of each multi-run, the goal-seeking part of EARTH compares the predictions with the experiments, and then adjusts the constants in such a direction as will (it hopes) make the agreement better.

Because Goal-Seeker is new, CHAM cannot yet report extensive achievements. However, its potential is great; so it is being provided for interested users to try.

7. VR-enhancements: to editor and viewer

The VR-Editor and Viewer enhancements are far too numerous to be listed. High-lights are:

Common to VR-Editor and VR-Viewer



In addition, there have been many behind-the-scenes improvements, such as the sealing of "memory leaks" which sometimes caused the program to "hang" when started and stopped many times.

CHAM is confident that many users will conclude that the up-grade to PHOENICS 3.4 has been worth making for the VR-enhancements alone.

8. PARSOL: striding ahead

PARSOL, the means of handling solid bodies which intersect cell edges between cell corners, has also been made more robust and accurate.

The developments have been driven in part by CHAM's concern with flows in and around moving humans, as illustrated here, where the smoothness of the contours is achieved despite the coarseness of the grid.

CHAM's progress is rapid in this sector. Soon the walking man will be joined by running and dancing men, with full interaction with the surrounding fluid.

9. Parallel: 2-processor PCs go twice as fast as one

Two-processor PC's are not very much more expensive than single-processor ones. CHAM has therefore paid particular attention to ensuring that the parallel version of PHOENICS performs well on them, whether the operating system is Linux or Windows-NT.

If a 2-processor machine is not asked to do anything else at the same time, Parallel-PHOENICS runs for many problems (almost) twice as fast as sequential PHOENICS on one of them.

The small price differential must surely make 2-processor parallel PHOENICS a good bargain for many users.