Encyclopaedia Index

PHOENICS-VR Reference Guide

CHAM Technical Report TR/326

PHOENICS 2012

Document last revised 26/10/12

Contents

  1. Introduction
  2. VR Environment
  3. VR Editor
  4. VR Editor Hand-Set
  5. VR Editor Object Management
  6. VR Editor Object Dialogs
  7. Object Types and Attributes
  8. Importing CAD Data
  9. Treatment of Solid-Fluid Boundaries - PARSOL
  10. Default Geometries
  11. VR Editor Main-Menu
  12. Space and Time Grids
  13. Q1 Implementation
  14. VR Viewer
  15. Program start-up arguments
  16. Memory management

Introduction

This document describes in detail all the control buttons and switches available in the PHOENICS VR-Editor, PHOENICS 2010. The reader should already be familiar with TR/324 - Starting with PHOENICS-VR.

The Purpose of This Document
Modes of Operation
Applicability
The VR-Environment Screen Layout Under Windows
Getting Help


VR Environment

This section describes the menus and dialog boxes available from the top bar of the main VR-Editor/Viewer graphics window. In some cases, the same functions can be accessed via the icons on the tool bar.

File Menu,
Settings Menu,
View Menu,
Run Menu,
Options Menu,
Compile Menu,
Build Menu,
Help,
The Tool Bar,
The Status Bar


VR Editor

The VR-Editor is the default mode of operation of the PHOENICS-VR Environment. In this mode, it is possible to set up and modify the case to be analysed.


VR Editor Hand-Set

This section describes the functions of the VR-Editor hand-set buttons.

Mesh Toggle,
Wireframe Toggle,
Geometry Cells,
Top View Toggle,
Axis Toggle,
Main Menu,
Management,
Rotate Object Down / Up,
Duplicate Object or Group,
Duplicate using Array,
Delete object,
Zoom in / Move Forward,
Zoom Out / Move Backward,
Reset View Parameters,
View Left / Move Left,
View Right / Move Right,
View Up / Move Up,
View Down / Move Down,
Tilt Left / Angle Up,
Tilt Right / Angle Down,
X / Y / Z Position Up / Down,
X / Y / Z Size Up / Down
Mouse Control
Quick-Zoom
Fly-through Mode


VR Editor Object Management

In the VR-Editor, all geometrical features are represented by objects. They may represent for example blockages, inlets, outlets or heat sources.

This section describes how objects can be manipulated - created, modified or deleted.

Overview

Managing Objects

Object Menu

New Object, Import Object, Copy Object, Array Object, Select All, Refresh, Close

Action Menu

Open object dialog, Hide object, Reveal object, Delete object, Modify colour, Object wireframe, Object affects grid, Object constrained by domain, Object selectable, Surface contours, Show nett sources

View Menu

Group Menu

Save, Delete, Modify

Context Menu


VR Editor Object Dialog

This section describes the functions of the VR-Editor object dialog.

Basic Functions

Object Selection

Object 'General' Page

Object name, Object Type

Object 'Size' Page

Object 'Place' Page

Object Position, Object Rotation Angle

Object 'Shape' Page

Using the Supplied Geometry Libraries, Displaying Geometry File Shapes, Importing Shapemaker Geometry, Loading CAD Geometries, Importing CAD geometries by Group, Applying Textures, Body-Fitted Co-ordinates

Object 'Options' Page

Object Colour, Rotation Options

Rotation Centre, Rotation Mode, Rotate Object Face, Hide Object, Wireframe, Object Affects Grid, Object Constrained by Domain


Object Types and Attributes

This chapter describes the object types, and their attributes. The attributes of each object type are specific to that type.

Object Type Brief Description
Blockage 3D, solid or fluid. Can apply heat and momentum sources.
Inlet 2D, fixed mass source.
Angled-in 3D, fixed mass source on surface of underlying BLOCKAGE object.
Wind 3D, whole domain, applies wind profiles at domain boundaries
Wind_Profile 2D, fixed mass source following atmospheric boundary layer.
Outlet 2D, fixed pressure.
Sun 3D, whole domain, applies solar radiation heat load within domain.
Angled-out 3D, fixed pressure on surface of underlying BLOCKAGE object.
Plate 2D, zero thickness obstacle to flow. May be porous.
Thin Plate 2D, nominal thickness for heat transfer.
Fan 2D, fixed velocity
Point_history single cell transient monitor point.
Fine Grid Vol 3D region of fine grid.
User Defined 2D or 3D, for setting user-defined sources (PATCH/COVAL).
Celltype  2D or 3D, for setting user-defined sources (cannot affect grid).
Null 2D or 3D. Used to cut the grid for mesh control.
PCB  3D, solid or fluid with non-isotropic thermal conductivity
Pressure Relief single cell fixed pressure point.
ROTOR 3D, rotating co-ordinate zone in cylindrical-polar grid
Drag_lift 3D, region over which momentum imbalance (force) will be calculated.
Assembly 2D or 3D container object for multi-component object
Transfer 2D, transfers sources between calculations
Clipping_plane 3D, graphically clips the image. No effect on solution.
Plot_surf 2D or 3D, provides surface for contour or vector plots in Viewer. No effect on solution.

InForm Commands

Many objects types have a button labeled 'InForm Commands' on their attributes page. This leads to a dialog from which a selection of InForm commands can be attached to this object. It is described in here.


Importing CAD Data

This section describes how to import CAD data from STL or DXF format files.

Introduction
Allowable Geometries
Importing a Single CAD Object
Assembling a Complete Geometry 
Translation Errors


Treatment of Solid-Fluid Boundaries - PARSOL

The VR-Editor allows irregular geometries to be attached to rectangular objects. Within the solver, Earth, the intersections of the geometry with the grid lines are calculated.

By default, the Earth solver uses an accurate representation of the true geometry. This is the Partial Solid method, PARSOL.

In this method, sometimes known as a 'cut-cell' technique, the areas and volumes of partially-blocked cells are calculated to a high degree of accuracy, and the equation formulation is modified to account for the local non-orthogonality.

Fine-grid volumes can be used to increase the mesh density near a surface, and thus improve the resolution still further.

PARSOL works in Cartesian and Cylindrical-Polar co-ordinates, but is not available for BFC geometries.

The PARSOL method can be de-activated by setting Partial Solids Treatment to be OFF in the Geometry panel of the Main menu.

Sloping or curved surfaces are then represented in a 'stair-case' fashion. If the centre of a cell falls inside a solid, the entire cell is taken to be solid. If it falls in the fluid, the entire cell is open to flow.

In many cases, such an approach will provide entirely satisfactory results. In some cases however, such a representation is inadequate and will result in unacceptable loss of pressure.

The first image shows a flow through a turn-around duct with PARSOL turned off, the second with it turned on.


IMAGE: Without PARSOL


IMAGE: With PARSOL

The case in question is Library case 804.


Default Geometries

When an object is first created, and a type is selected, one of the following .dat files will be used as the default geometry:

Object Type Cartesian Grid Polar Grid
Blockage (solid) Cube14 (grey) Polcu8 (grey)
Blockage (solid+heat) Cube4 (red) Polcu7 (red)
Blockage (fluid) Cubet (transparent grey) Polcubt2 (transparent grey)
Blockage (fluid+heat) Cubet1 (transparent red) Polcubt1 (transparent red)
Inlet / Angled-in Cube3t (transparent purple) Polcu5t (transparent purple)
Outlet / Angled-out Cube12t (transparent light blue) Polcubet (transparent light blue)
Plate Cube11 (light brown) Polcu10 (light brown)
Plate + heat Cube13 (orange) Polcu2 (orange)
Thin plate Cube11 (light brown) Polcu10 (light brown)
Fan Cube2t (transparent white) or Cylpipe if circular Polcu4t (transparent white)
Point_history Default (khaki) Poldef (khaki)
Fine grid volume Fine (special wire-frame) Polfgv
User defined1 Default (khaki) Poldef (khaki)
Celltype1 Default (khaki) Poldef (khaki)
Null Wirexyz (wire-frame) Wirexyz (wire-frame)
PCB Cube1 (green) Polcu9 (green)
Pressure relief Cubet (transparent grey) Polcubet (transparent grey)
ROTOR n/a Polcub4t (transparent white)
Drag_lift Drag (special wire-frame) Poldrag (special wire-frame)
Wind_profile / Wind Wind (transparent mauve) n/a
Sun Sun (transparent orange) n/a
Transfer Cubetran (transparent green) Polcubtra (transparent green)

These files are in the \phoenics \d_satell\d_object\public\default folder.

When the type of an object is subsequently changed, the geometry file will be changed according to the above table, as long as the current geometry is one of the above.

If the user has selected any other geometry, such as shapes\cylinder, then VR-Editor will not change it. Object types marked 1 in the table will also not change the geometry.

A description of the data file format is given in How do I make my own Clipart/Geometry files for PHOENICS-VR?

On exit from VR-Editor, a file called FACETDAT is created, which contains the definitions of the all the facets for all the non-cuboid objects. This file is read and interpreted by EARTH.

It is possible to make VR-Editor use a different geometry from that displayed on screen to create the FACETDAT file. This can be useful if the displayed geometry contains more detail than is required for the simulation.

Geometries whose file names appear in the file \phoenics \d_satell \d_object \replace.lst will be replaced by the default cube, or any other geometry specified there. The default replace.lst contains:

* File name replace.lst --------------------------------------- 24.12.02
*
* Geometries whose file names match those listed below will be
* replaced by the default cube at the time of setting facet cells and
* before writing facetdat file. If a second geometry name is listed,
* that will be used instead of the default cube.
* If a rotation code is required for the replacement geometry, it can
* be specified after the second name.
*
fan
fan1
fan2
fire
fire2
window
window1
window2
window3
window4
paddle
elgouna1  elg8
elcomp1   elcorep
frnt_whl cylinder 5
back_whl cylinder 5

On the last four lines, the second string contains the name of the geometry used to create the FACETDAT entry. On the last two lines, a rotation code is also specified.


VR Editor Main-Menu

The Main Menu is where all the domain-related settings, such as domain size, variables solved, physical properties, numerical and output controls are set. Any source which operates over the whole domain is also set from here.

Geometry: Grid and time-step settings
Models: Solution of variables, turbulence models etc.
Properties: Density, viscosity etc.
Initialisation: Initial values.
Help: Help on that panel.
Top menu: Go to the top level.
Sources: Whole-domain sources, e.g. buoyancy.
Numerics: Solution control settings.
GROUND: Values for GROUND.
Output: Print-out and field dumping controls.
OK: Return to VR-Editor. This button only appears on the top panel.
INFORM: Start the In-Form Editor.
Domain Faces: Apply fixed-flow, fixed pressure or friction boundary conditions to selected domain faces.


Space and Time Grids

This section describes the spatial co-ordinate systems available, and shows how the associated grids can be modified. It also shows how to set time-step distributions for transient cases.

Spatial Grids
Switching Co-ordinate Systems
Cartesian and Cylindrical-Polar Co-ordinates
Body-Fitted Co-ordinates
Time Grids


Q1 Implementation

This section describes how the settings made in the various object dialog boxes are captured in the Q1 file. The description concentrates on those features unique to PHOENICS-VR. Standard Q1 settings are not described in detail - the meaning of PIL statements can be ascertained from the relevant Encyclopaedia entries.

Domain-related Settings

Object-related Settings

Common settings,
Blockage,
Inlet,
Angled-in,
Wind_profile
Outlet,
Angled-out,
Plate,
Thin Plate,
Fan,
Point_history,
Fine Grid Volume,
User Defined,
Cell Type,
Null,
PCB,
Pressure Relief
ROTOR
Assembly
Transfer
Clipping_plane
Plot_surface
GENTRA Exit Boundary

Hand Editing


VR Viewer

This section describes the functions of the VR-Viewer.

VR Viewer Overview
Selecting the Files to Plot
VR-Viewer Environment
VR-Viewer hand-set
The Object Dialog Box
VR-Viewer Scripting (Macro) facility
Saving Animations

Short cuts to plotting functions:

Contours Surface contours Vectors Iso-surfaces Streamlines Line plots


Program start-up arguments


Memory management


Contents list