460 likes | 630 Views
PHOENICS 3.6.1 May 2005. What is PHOENICS. PHOENICS is a general-purpose CFD code The name PHOENICS is an acronym standing for:. P arabolic H yperbolic O r E lliptic N umerical I ntegration C ode S eries. 1-,2- and 3-D geometries
E N D
PHOENICS 3.6.1 May 2005
What is PHOENICS • PHOENICS is a general-purpose CFD code • The name PHOENICS is an acronym standing for: P arabolic H yperbolic O r E lliptic N umerical I ntegration C ode S eries
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 Main Features of PHOENICS
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 • 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 • 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 • 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.