phoenics 3.6.1 may 2005

PHOENICS 3.6.1

May 2005

What is PHOENICSP arabolic

H yperbolic

O r

E lliptic

N umerical

I ntegration

C ode

S eries

• PHOENICS is a general-purpose CFD code

• The name PHOENICS is an acronym standing for:

Main Features of PHOENICS• 1-,2- and 3-D geometries• Cartesian, Polar and Body-Fitted Coordinates• Local multi-level fine-grid embedding • Cut-cell technique for complex geometry• Conjugate Heat Transfer• Single or Multi-Phase Flow• Particle Tracking• Chemical reaction• Radiation• Non-Newtonian Flow• Choice of equation solvers and differencing schemes• Open-source routine for user-coding• Automatic generation of user code

Contents

• This presentation shows some of the new features in PHOENICS 3.6

• The talk is in four parts:– General improvements (common to all modules)– Pre-processor (VR-Editor)– Post-processor (VR-Viewer)– Solver (Earth)

General Improvements

• In PHOENICS 3.6, the memory management for VR-Editor, Earth, VR-Viewer, PHOTON / AUTOPLOT and PINTO is handled dynamically.

• The need to recompile and relink just to have larger arrays has finally been banished.

General Improvements

• Initial memory allocations are read from the CHAM.INI configuration file.

• If more memory is needed, each module will expand the relevant arrays as needed.

VR Editor Improvements

• The control of multiple objects has been eased by the introduction of the Object Management dialog.

• Any column can be sorted in ascending order.

VR Editor Improvements

• A right-click brings up a context-dialog.

VR Editor Improvements

• The dialog allows standard Windows multiple selection using shift and control.

• Objects can be selected from the screen or from the Object management dialog, with mouse control turned on.

• Multiple selections automatically make a temporary group.

VR Editor Improvements

• All selected objects can be moved together, have their colour and transparency set, and be revealed or hidden.

• Attribute changes made to one object can be propagated through all objects of that type in the group.

VR Editor Improvements• Groups can be saved by clicking on Group /

Save. There is no limit on the number of groups saved.

• Saved groups are written to Q1, and so are

available in the next run.

VR Editor Improvements• Groups can be saved by clicking on Group /

Save. There is no limit on the number of groups saved.

• Saved groups are written to Q1, and so are

available in the next run.

VR Editor Improvements

• The Object dialog itself has been turned into a tabbed dialog.

VR Editor Improvements

• A new object type ASSEMBLY has been introduced.

• The assembly object acts as a ‘container’ for any number of other objects, which go together to make a component.

• Objects are added to an assembly object through the Hierarchy dialog.

VR Editor Improvements

• Components can be added or removed from an assembly

VR Editor Improvements

• All size and position changes made to the assembly object are also applied to all the components.

VR Editor Improvements

• All the objects in the assembly can then be exported to a single file.

VR Editor Improvements

• The saved assembly objects can then be imported into another model.

VR Editor Improvements

• A new object type WIND_PROFILE has been introduced.

• The inlet velocity profile can be– Logarithmic– Power-law

VR Editor Improvements• At PLATE objects, the roughness height and

wall-function coefficient can be set independently for each plate, and for each side of an internal plate.

VR Editor Improvements• Objects can be partially pushed out of the

domain, to allow:

– Solution over one half of a body, or

– Solution over any part of a large STL

VR Viewer Improvements

• The Object Management dialog is also present in the Viewer.

• It can turn the surface contouring on or off for the selected objects

VR Viewer Improvements

• A similar approach has been taken to Slice management.

• Slices can be turned on & off individually.

• They can be moved, and have their orientation changed.

VR Viewer Improvements

• There is also a Streamline management dialog

• Streamlines can be turned on & off individually

• The start location for each track can be changed

VR Viewer Improvements

• Streamlines can start:– From the probe location

– Along a line

– Around a circle

VR Viewer Improvements

• Streamlines can be animated using balls, vectors or line segments.

• The animation can be saved as an AVI or animated gif, which will play in Windows Media Player or any browser.

VR Viewer Improvements

VR Viewer Improvements

VR Viewer Improvements

VR Viewer Improvements

• The control dialogs for Contours, Vectors, Iso-surfaces and Plot limits have been made into a single tabbed dialog.

• Several other small control dialogs have been amalgamated.

VR Viewer Improvements

• The positions of the minimum and maximum values of any variable can be shown as blue and red balls.

• Double-clicking a ball shows the value

VR Viewer Improvements

• Double-clicking the probe shows a dialog from which the probe position can be changed.

• It also shows the probe value, and the low and high values and their positions.

VR Viewer Improvements• The sources and sinks for an object can be

displayed:

VR Viewer Improvements• A ‘quick-zoom’ function has been added

General Improvements

• A new ‘Automatic Convergence’ feature has been added. It is activated by setting

CONWIZ=T

• This is the default for all new cases set through the VR-Editor.

• Existing cases can be easily converted.• The feature is described in a separate

document available through POLIS.

General Improvements• IMMERSOL is now compatible with PARSOL

Recent Applications

Recent Applications

Recent Applications

• Wind tunnel to PHOENICS CFD results were within 0.5% for drag.

• PHOENICS has also allowed the company to test a number of design concepts that would have been impractical from a cost point of view by any other method.

• Even a scale model of a truck is big/heavy and as a result needs a full size wind tunnel.

Recent Applications

Recent Applications

• The drag differences between open and closed should be around 5%, PHOENICS came up with 8%.

• However the models were made-up by a student and not entirely accurate in detail.

• Total drag force for these cars is from 500Lbs to 750Lbs of drag force at 150mph, with down force being 3.5 to 5 times this figure.

Recent Applications

• Bearing in mind that the CFD models do not have any radiators and that the rear wing is not accurate the figures obtained are as follows:– Open LMP Drag – 520Lbs– Closed LMP Drag – 480Lbs

• These are on the low side, but consistent given that the points above would work to reduce drag.

Recent Applications

• In both cases the down force is low, being slightly less than 1 in both cases. The reasons being…– The ride height is on the high side.– The car is parallel to the ground. A nose down

attitude will help to promote down force.– Accurate modelling of the rear wing profile/angle

will increase down force.

Recent Applications

• In summary the comparative study has shown that:– the closed variant is more drag efficient, and – that further work is required on the models to

produce absolute, as opposed to comparative figures.

END