phoenics computer simulation of fluid flow, heat flow, chemical reactions and stress in solids. cham...

PHOENICSPHOENICS

Computer Simulation of Fluid Flow, Heat Flow, Chemical Reactions and Stress in Solids. CHAM

Minkasheva Alena

Thermal Fluid Engineering Lab.Department of Mechanical EngineeringKangwon National University

2007.05.04Part 1

Application of Environment Spatial Information System

Contents

Chapter 1. PHOENICS Overview

1. What PHOENICS is2.The components of PHOENICS

2.1 The main functions of PHOENICS2.2 The structure of PHOENICS2.3 The inter-communication files2.4 How the problem is defined2.5 How PHOENICS makes the predictions2.6 How the results are displayed2.7 PHOENICS options

3. Physical content of PHOENICS4. Mathematical features of PHOENICS

4.1 Variables

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Contents

4.2 Storage4.3 Grids4.4 The Balance Equation4.5 Auxiliary Equations4.6 Solution of Equations4.7 Boundary Conditions

5. Simulation of multi-phase flow in PHOENICS6. Turbulence models in PHOENICS7. Radiative-heat-transfer models in PHOENICS8. Chemical-reaction processes in PHOENICS9. Simultaneous solid-stress analysis10. Body-fitting in PHOENICS11. PHOENICS Application

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Contents

Chapter 2. The Virtual-Reality Interface

1. VR-Editor

1.1 What the Virtual-Reality Editor creates1.2 Domain Attributes Menu1.3 Object Management Panel1.4 Object Types and Attributes1.5 The VR Editor Control Panel

2. VR Viewer

Chapter 3. PHOENICS Application Example “Simulation of Contaminant Flow”Pre-Processor VR-Editor Main Solver EarthPost-Processor VR-Viewer

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Chapter 1Chapter 1

PHOENICS Overview

• PHOENICS is a general-purpose software package which predicts quantitatively:

▪ how fluids (air, water, steam, oil, blood, etc) flow in and around: ᆞ engines ᆞ process equipment ᆞ buildings ᆞ human beings ᆞ lakes, river and oceans, and so on

▪ the associated changes of chemical and physical composition

▪ the associated stresses in the immersed solids

• “PHOENICS” - Parabolic Hyperbolic Or Elliptic Numerical Integration Code Series

1. What PHOENICS is 1

1. What PHOENICS is

• PHOENICS is employed by: ▪ scientists for interpreting their experimental observations

▪ engineers for the design of aircraft and other vehicles, and of equipment which produces power or which processes materials

▪ architects for the design of buildings

▪ environmental specialists for the prediction, and if possible control, of environmental impact and hazards

▪ teachers and students for the study of fluid dynamics,

heat transfer, combustion and related disciplines

• PHOENICS is a “CFD code” Computational Fluid Dynamics software

2

• PHOENICS performs three main functions:

1. Problem definition (pre-processing) in which the user prescribes the situation to be

simulated and the questions which are to be answered

2. Simulation (data-processing) by means of computation, of what the laws of

science imply in the prescribed circumstances

3. Presentation (post-processing) of the results of the computation, by way of

graphical displays, tables of numbers, and other means

2. The Components of PHOENICS2.1 The main functions of PHOENICS

2.2 The structure of PHOENICS 1

2.2 The structure of PHOENICS

• PHOENICS has a ‘planetary’ arrangement, with a central core of subroutines called EARTH, and a SATELLITE program, which accepts inputs through the Virtual Reality (VR) interface corresponded to a particular flow simulation.

• EARTH and SATELLITE are distinct programs.

• SATELLITE is a data-preparation program; it writes a data file which EARTH reads.

• PHOENICS users work mainly with SATELLITE, but they can access EARTH also in controlled ways.

• GROUND is the EARTH subroutine which users access when incorporating special features of their own.

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2.3 The inter-communication files

• Files which are used for communication between modules

▪ Q1, the user-readable input-data file, which is written in PIL, the PHOENICS Input Language, and is the main expression of what the user wishes to achieve.

▪ EARDAT, an ASCII file which expresses in EARTH-understandable form what the user has prescribed by way of Q1.

▪ PHI, which is written by EARTH in accordance with a format which enables PHOTON, AUTOPLOT and the Viewer to display the results of the computation graphically.

▪ RESULT, which is an ASCII file expressing the results in tabular and line-printer-plot form

2.4 How the problem is defined

▪ geometryshapes, sizes and positions of objects and intervening spaces;

▪ materialsthermodynamic, transport and other properties of the fluids and solids involved

▪ processesfor example: whether the materials are inert or reactive;whether turbulence is to be simulated and if so by what model;whether temperatures are to be computed in both fluids and solids;whether stresses in solids are to be computed

▪ gridthe manner and fineness of the sub-division of space and time, what is called the "discretization"

▪ other numerical (non-physical) parametersaffecting the speed, accuracy and economy of the simulation

• Problem definition involves making statements about:

2.5 How PHOENICS makes the predictions

▪ expressing the relevant laws of physics and chemistry, and the "models" which supplement them, in the form of equations linking the values of pressure, temperature, concentration, etc which prevail at clusters of points distributed through space and time

▪ locating these point-clusters (which constitute the computational grid) sufficiently close to each other to represent adequately the continuity of actual objects and fluids

▪ solving the equations by systematic, iterative, error-reduction methods, the progress of which is made visible on the VDU screen

▪ terminating when the errors have been sufficiently reduced affecting the speed, accuracy and economy of the simulation

• PHOENICS simulates physical phenomena by:

2.6 How the results are displayed

▪ It has its own stand-alone graphics package called PHOTON; and it can also export results to such third-party packages as TECPLOT, AVS, and FEMVIEW.

▪ PHOENICS can also take the results of its flow predictions back into the same VIRTUAL-REALITY environment as is used for setting up the problem at the start.

▪ Numerical results are provided, in the RESULT file. This, when the appropriate commands in the Q1 file, can provide either sparse or voluminous information

• PHOENICS can display the results of its flow simulations in a wide variety of forms

2.7 PHOENICS options:

1. Advanced-multiphase

2. Body-fitted-coordinate

3. Advanced-chemistry

4. GENTRA (particle tracking)

5. Multi-block and fine-grid-embedding

6. Multi-fluid

7. Advanced-algorithms

8. MIGAL, the multi-grid solver

9. PLANT fortranizer

10. Advanced-radiation

11. Simultaneous-solid-stress

12. Advanced-turbulence

13. Two-phase

3. Physical content of PHOENICS

• laminar or turbulent

• compressible or incompressible

• steady or unsteady

• chemically inert or reactive

• single- or multi-phase

• in respect of thermal radiation:

- transparent

- participating by way of absorption and emission

- participating by way of scattering

• PHOENICS simulates flow phenomena which are:

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• empty of solids, or

• wholly or partially filled by finely-divided solids at rest (as in 'porous-medium' flows), or

• partially occupied by solids which are not small compared with the size of the local computational cells

• The space in which the fluid flows may be:

The solids may interact thermally with the solids.

Such immersed solids can also participate in radiative heat transfer.

The thermally and mechanically-induced stresses and strains in the immersed solids can also be computed by PHOENICS.

The thermodynamic, transport (including radiative), chemical and other properties of the fluids and solids may be of arbitrary complexity.

3. Physical content of PHOENICS 2

• dependent - the subject of a conservation equation

• auxiliary - constant, or derived from an algebraic expression

• Variables may be thought of as being:

4.1 Variables

• Dependent:

• Scalars:

- Pressure

- Temperature

- Enthalpy

- Mass fractions

- Volume fractions

- Turbulence quantities

- Various potentials

• Vectors:

- Velocity resolutes

- Radiation fluxes

- Displacements

4. Mathematical features1

4.1 Variables

• Auxiliary:

• Scalars:

- Density

- Viscosity

- Conductivity

- Diffusivity

- Specific heat

- Thermal expansion coefficient

- Inter-fluid transport

- Absorptivity

- Compressibility

• Vectors:

- Various non-isotropic properties

- Gravity forces

- Other body forces

2

4.1 Variables

• The quantities defining the problem geometry can also be divided into scalar and vector categories:

• Geometric: • Scalars:

- Cell volumes

- Volume porosity factors

- Inter-fluid surface area per unit volume

• Vectors:

- Cell center coordinates

- Cell corner coordinates

- Center to center distances

- Cell surface areas

- Cell area porosities

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• Scalars - These are stored at the center points of six-sided cells, with values supposed to be typical of the whole cell.

• Vectors - These are stored at the center points of the six cell faces

4.2 Storage

• Nomenclature A compass-point notation: P = Cell center

N,S,E,W,H,L = Neighbour-cell centers

S → N = Positive IY

W → E = Positive IX

L → H = Positive IZ

T = Cell center at previous time step

An array of cells with the same IZ is referred to as a SLAB

4.3 Grids

• Storage locations Vector quantities are computed by reference to cells which are staggered with respect to the scalar cells

3 velocities and 1 scalar share the same cell index (IX,IY,IZ).

Any scalar or vector quantity can only be referenced by a unique (IX,IY,IZ) index

4.3 Grids

• Types of Grid PHOENICS grids are structured - cells are topologically Cartesian brick elements• PHOENICS grids may be :

- Cartesian

- Cylindrical-polar

- Body fitted i.e. arbitrarily curvi-linear, orthogonal or non-orthogonal

The grid distribution can be non-uniform in all coordinate directions • For cylindrical-polar coordinates:

- X (or I) is always the angular direction

- Y (or J) is always the radial direction

- Z (or K) is always the axial direction

• mass

• momentum

• energy

• material (ie chemical species)

• other conserved entities (e.g. electrical charge)

over discrete elements of space and time, i.e. 'finite volumes' known as 'cells'

• The equations solved by PHOENICS are those which express the balances of:

4.4 The Balance Equation

• Basic form The basic balance, or conservation equation is just:

Outflow from cell - Inflow into cell = Net source within cell


• TermsThe terms appearing in the balance equation are:

- Convection (i.e., directed mass flow)

- Diffusion (i.e., random motion of electrons, molecules or larger structures e.g., eddies)

- Time variation (i.e., directed motion from past to present - accumulation within a cell)

- Sources (e.g., pressure gradient or body force for momentum, chemical reaction for energy or chemical species)


• The Generalized Form The single phase conservation equation solved by PHOENICS can be written as:

where: - the variable in question

- density

- vector velocity

- the diffusive exchange coefficient for

- the source term

Sx

Uxt

)(

U

S


• Particular Forms

where , are the turbulent and laminar viscosities, , are the turbulent and laminar Prandtl/Schmidt Numbers

wvu ,,

)( LT

...

frictiongravityx

pS

h

h

L

L

T

T

PrPr

... sourcesheatDt

DpS

T L

TPr LPr

Momentum Enthalpy

1

0

sourcesboundaryS 0

Continuity


• Numerical solution• The balance equations cannot be solved numerically in

differential form. Hence, PHOENICS solves a finite-volume formulation of the balance equation.

• The FVE's are obtained by integrating the differential equation over the cell volume.

• Interpolation assumptions are required to obtain scalar values at cell faces and vector quantities at cell centers.

• No Taylor series expansion or variational principle is used


• Finite Volume FormAfter integration, the FVE has the form:

where:

The neighbour links, the a's, have the form

convection diffusion transient

termssourceaaaaaaaa TTLLHHWWEESSNNpp

TLHWESNp aaaaaaaa

dt

densityvolume

ncedista

tcoefficienexchangeareadensityvelocityarea


• Correction FormThe equation is cast into correction form before solution.

In correction form, the sources are replaced by the errors in the real equation, and the coefficients may be only approximate. The corrections tend to zero as convergence is approached, reducing the possibility of round-off errors affecting the solution.

The neighbor links:

- Increase with inflow velocity, cell area, fluid density and transport coefficient

- Decrease with internodal distance

- Are always positive

4.5 Auxiliary Equations

To close the equation set, auxiliary equations must be provided for:

• Thermodynamic properties: density, (enthalpy, entropy)

• Transport properties: viscosity, diffusivity, conductivity

• Source terms: chemical kinetic laws, radiation absorption, viscous dissipation, Coriolis etc.

• Interphase transport: of momentum, energy, mass , chemical species etc.

There may also be 'artificial' auxiliary equations, such as

• False transients (for relaxation)

• Boundary conditions

• computing the imbalances of each of the entities for each cell

• computing the coefficients of linear(ised) equations which represent how the imbalances will change as a consequence of (small) changes to the solved-for variables;

• solving the linear equations;

• correcting the values of solved-for variables, and of auxiliary ones, such as fluid properties, which depend upon them:

• repeating the cycle of operations until the changes made to the variables are sufficiently small

• Because the whole equation system is non-linear, the solution procedure is iterative, consisting of the steps of:

• tri-diagonal matrix algorithm

• (a variant of) Stone's 'Strongly Implicit Algorithm',

• conjugate-gradient and conjugate-residual solvers

• Various techniques are used for solving the linear equations:

4.6 Solution of Equations

4.7 Boundary Conditions

• General formBoundary Conditions are represented in PHOENICS as linearized sources for cells adjacent to boundaries:

is termed the COEFFICIENT.

is termed the VALUE.

is added to ,

and is added to the RHS of the equation for

pBCBCaS

BC

BCBCa p

BCp

BCBChhP aa

aa

BCa

BCapa

4.7 Boundary Conditions

• Particular formsFor a fixed value boundary, is made very big. The effect is:

For a fixed flux boundary, is made very small, and is set to the required flux.

Linear and non-linear conditions can be set by appropriate prescription of and

BCBCa

BCa

BCp

BCBChhP aa

aa

BC

BCBCP anumbersmallvery

anumbersmallvery

BCP

tinyatiny

sourcetinya

p

hh

P

p

hhP a

sourcea

BC

BCa

BCa

5. Simulation of multi-phase flow in PHOENICS

• suspensions of oil droplets in water, or of water droplets in oil;

• the air-snow mixture in an avalanche;

• the sand-air mixture in a sandstorm;

• the "mushy zone" of mixed solid and liquid metal in a casting mould;

• the water-air mixture in a shower bath;

• the gas-oil-water mixture, in the pores within rock, in a petroleum-recovery process;

• droplets of fuel oil mixed with hot gases in a combustion chamber

• Examples:

• Multi-phase-flow phenomena are, for PHOENICS, those in which, within the smallest element of space which is considered (the computational cell) several distinguishable materials are present.

1. As two inter-penetrating continua, each having at each point in the space-time domain under consideration, its own:

- velocity components, - temperature, - composition, - density, - viscosity, - volume fraction, etc

2. As multiple inter-penetrating continua having the same variety of properties

3. As two non-interpenetrating continua separated by a free surface

4. As a particulate phase for which the particle trajectories are computed as they move through a continuous fluid

• Simulation methods in PHOENICS:

5. Simulation of multi-phase flow in PHOENICS

6. Turbulence models in PHOENICS

• The flows which PHOENICS is called upon to simulate are, more often than not, turbulent, by which is meant that they exhibit near-random fluctuations, the time-scale of which is very small compared with the time-scale of the mean-flow, and of which the distance scale is small compared with the dimensions of the domain under study

• A broad-brush summary of the satisfactoriness of the most-widely-used turbulence models is:- for predicting time-average hydrodynamic phenomena and the macro-mixing of fluids marked by conserved scalars,

the models are "not bad"; but

- for the simulation of micro-mixing, which is essential if chemical- reaction rates are to be predicted, they are very poor indeed

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• heat and mass transfer

• chemical reaction

• multi-phase effects

• Further distinction between models can be made by reference to their handling (or non-handling) of:

• Turbulence models in PHOENICS can be classified as belonging to one or other of three groups, namely:

1. those which employ the Effective Viscosity Hypothesis (EVH)

2. those which specifically AVOID the EVH

3. those which may make some INESSENTIAL use of the EVH

6. Turbulence models in PHOENICS 2

Sub-group 1.1 in which no differential equations are used• prescribed EV - EV is given a uniform value

• LVEL - EV is computed from the velocity, the laminar viscosity and the distance from nearby walls

• Prandtl mixing-length - EV is computed from the velocity gradient length and a prescribed length scale

• Van-Driest - as for Prandtl mixing length, but with low-Reynolds-number modification

Sub-group 1.2 in which one differential equation is used

• Prandtl energy - EV is prescribed-length * SQRT(KE) where KE is energy of turbulence computed from a differential transport equation

Sub-group 1.3 in which 1 or 2 differential equations are used

• TWO-LAYER KE-EP - as for KE-EP except that only the KE equation is solved near the wall, where the length scale is treated as known

• Group 1 - which employ the EVH


Sub-group 1.4 in which two differential equations are used

• k-epsilon (KE-EP) - EV is proportional to KE**2/EP, where KE and EP (dissipation rate of KE) are computed from differential transport equations

• CHEN-KIM KE-EP - as for KE-EP, but with a "dual-time-scale concept" making the formulae depend upon the energy-production rate P

• RNG-derived KE-EP - as for KE-EP, but with a "re-normalization- group concept" making the formulae depend upon the energy-production rate P

• LAM-BREMHORST - as for KE-EP, but with low-Reynolds number extension requiring knowledge of the distance from the nearest wall

• Saffman-Spalding KE-VO - EV is proportional to KE/W**0.5, where KE and W (RMS vorticity fluctuations) are computed from dif. transport eqs.

• Kolmogorov-Wilcox KE-OMEGA - EV is proportional to KE/OMEGA, where KE and OMEGA ("turbulence frequency") are from dif. transport eqs.

Sub-group 1.5 in which four differential equations are used

• TWO-SCALE KE-EPEV - is computed in a similar manner to that of KE-EP model; but there are two turbulence- energy variables, KP and KT, and two dissipation-rate variables, EP and ET


• REYNOLDS-stress - EV is not used. Instead, the shear stresses are themselves the dependent variables of differential transport equations, usually six in number

• Group 2 - not employing the EVH

• Smagorinsky - EV is used only to resolve the small-scale subgrid-scale motion, the main transfers of momentum being computed by performing three-dimensional time-dependent solutions of the Navier-Stokes equations with the finest affordable space and time sub-divisions

• Two-fluid - EV is either not used at all, or is deduced from the local velocity differences between the two intermingling fluids which are used to describe the turbulent fluid mixture

• Multi-fluid - as for TWO-FLUID, except that, there being many fluids present, EV can be derived from their various velocities in a wider variety of ways

• Group 3 - which may or may not employ the EVH


7. Radiative-heat-transfer models in PHOENICS

• IMMERSOL method is:• computationally inexpensive;

• capable of handling the whole range of conditions from optically-thin (ie transparent) to optically-thick (ie opaque) media;

• mathematically exact when the geometry is simple; and

• never grossly inaccurate

• A method which is unique to PHOENICS, and is especially convenient when radiating surfaces are so numerous, and variously arranged, that the use of the view-factor-type model is impractically expensive, is IMMERSOL

8. Chemical-reaction processes in PHOENICS

• Chemical reactions are simulated by PHOENICS in several ways, including:

• SCRS - "the Simple Chemically Reacting System" built into user-accessible Fortran coding

• CREK - a set of user-callable subroutines which handle the thermodynamics and finite-rate or equilibrium chemical kinetics of complex chemical reactions

• CHEMKIN 2 - the public-domain code to which PHOENICS has an interface

• PLANT - which enables users to introduce new reaction schemes and material properties by way of formulae introduced into the data-input command file, Q1

• PHOENICS can handle the combustion of gaseous, liquid (e.g. oil-spray) and solid (e.g. pulverized-coal) fuels.

9. Simultaneous solid-stressanalysis

• Engineering examples of fluid/heat/stress interactions: • gas-turbine blades under transient conditions

• "residual stresses" resulting from casting or welding

• thermal stresses in nuclear reactors during emergency shut-down

• manufacture of bricks and ceramics

• stresses in the cylinder blocks of diesel engines

• the failure of steel-frame buildings during fires

• It is frequently required to simulate fluid-flow and heat-transfer processes in and around solids which are, partly as a consequence of the flow, subject to thermal and mechanical stresses

• Often it is the stresses which are of major concern, while the fluid and heat flows are of only secondary interest

• PHOENICS is enable to compute flows around such bodies by using "body-fitted-coordinate (i.e. BFC) grids"

10. Body-fitting in PHOENICS

• PHOENICS possesses its own built-in means of generating such grids; but it can also accept grids created by specialist packages, for example GeoGrid


• PARSOL allows flows around curved bodies to be computed on cartesian grids; and the solutions are often just as accurate as those computed on body-fitted grids.


11. PHOENICS Application

1.Engineering Application:• Aerospace

• Automotive

• Chemical process

• Combustion

• Electronics

• Marine

• Metallurgical

• Nuclear

• Petroleum

• Power

• Radiation

• Water etc.

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11. PHOENICS Application

2. Environment Application:• Atmospheric pollution

• Pollution of natural waters

• Safety

• Fire spread, etc.

3. Architecture and building science

• External flows ( e.g. Flow around bus shelter)

• Internal flows (e.g. Ventilation of a Concert Hall)

4. Other phenomena or features• Physical Models

• Chemical Processes

• Numerical Methods

• Grid Generation, etc.

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Chapter 2Chapter 2

The Virtual-Reality Interface

1. VR-Editor

▪ The Virtual-Reality user interface assists users to set up flow-simulation calculations, without having to learn the PIL. This data-input mode is called the VR-Editor

1.1 What the Virtual-Reality Editor creates

▪ The VR-Editor records the settings made by the user during his editing session in an ASCII file known as Q1.

▪ This file can be read, understood and edited. Usually, however, it will simply be stored for later use.

▪ In any case, the flow-simulation can begin immediately, if the user wishes, because two other files will also have been automatically written, one of which (FACETDAT) conveys the necessary geometrical information, while the other (EARDAT) carries everything else that the solver module needs to know.

▪ The switching from the VR-Editor to the solver, and for that matter to any other PHOENICS module, is rendered particularly easy by the pull-down menus accessible from the top bar of the VR-Editor screen.

1

.

• The VR-Editor is used for:▪ Setting the size of the computational domain;

▪ Defining the position, size and properties of objects which are to be introduced into it;

▪ Specifying the material which otherwise occupies the domain;

▪ Specifying the inlet and outlet boundary conditions;

▪ Specifying the initial conditions, necessary if the problem is a time-dependent one, and desirable otherwise for economy;

▪ Selecting a turbulence model, if the situation calls for it;

▪ Specifying the fineness of the computational grid;

▪ Specifying other parameters influencing the speed of convergence of the solution procedure

1.1 What the Virtual-Reality Editor creates 2

1.2 Domain Attributes 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

▪ The main menu is reached by:

- clicking the Main Menu button on the hand-set

- clicking the icon on the toolbar

- clicking ‘Settings – Domain attributes’ on the top bar of

the main graphics window

- double-clicking the Domain entry in the Object Management Panel

▪ This is the top panel of the main menu, it can be reached from any other panel by clicking on Top menu. It is the panel displayed whenever the Main menu is activated from the hand-set, and it is the only panel from which it is possible to return to the main VR-Editor environment

1.2 Domain Attributes MenuTop panel 1

▪ The buttons along the top of the panel allow the setting and modification of the case. In general, it is best to start at the top left, and work from left to right, as this minimises the chances of missing out settings

1.2 Domain Attributes MenuTop panel 2

1.2 Domain Attributes MenuGeometry

▪ For Cartesian and Polar co-ordinates, this is the same dialog that is displayed by clicking on the Grid mesh button on the hand-set

▪ Co-ordinate system: Toggles between Cartesian, cylindrical-polar and Body-Fitted (BFC)


▪ Inner radius (only for cylindrical-polar): Sets the inner radius for a cylindrical-polar grid


▪ Time dependence: Toggles between Steady and Transient


▪ Time step settings (only for transient): Displays a dialog for managing the time-step distribution


▪ Partial solids treatment (only for Cartesian): This activates the special treatment of partially-blocked cells, PARSOL


▪ Partial solids treatment settings: Dialog from which the min and max fluid volume fractions for PARSOL can be set. Any cell in which the fluid volume fraction is below the min value is considered fully-blocked, and any cell in which it is above the max is considered full-open


▪ Auto Meshing: Toggles between auto and manual meshing in each of the domain directions


▪ Domain size: Sets the total extent of the domain in the X, Y and Z directions. In cylindrical-polar co-ordinates, the X size is set in radians


▪ Number of cells: Sets the total number of cells in the X, Y and Z directions. If all regions are 'Set', or the grid is 'auto' this value cannot be changed directly as there are no 'Free' regions to accommodate the change


▪ Number of regions: This displays the current number of regions in each direction. This can only be changed by modifying objects or modifying the tolerance


▪ Modify region: This is the number of the region selected for modification. To modify a different region, enter its number directly and click 'Apply', or click OK, then click on the new region


▪ Size: This displays the size (in meters or radians) of the region selected for modification. The size of a region can only be changed by modifying objects or modifying the tolerance


▪ Distribution: This toggles between Power law and Geometrical progression. It controls how the cells within the region are spaced


▪ Cell and Power: This toggles between Free and Set. Free: the number of cells can be automatically adjusted as the total number of cells is changed, so as to keep the grid as uniform as possible. Set: the number of cells in this region, and their distribution, have been set by the user and cannot be automatically changed


▪ Cells in region: This initially displays the number of cells allocated to this region by the automatic meshing algorithm. The number of cells in this region can be changed by typing in a different value. Cells will be taken from, or distributed amongst other 'Free' regions to keep the total number constant


▪ Power/ratio: This sets the expansion power, or geometric expansion common ratio. The default setting of 1.0 gives a uniform mesh. Positive values mean that the expansion goes from the start of the region towards the end, negative values mean the expansion starts at the end and goes to the beginning


▪ Symmetric: This toggles between No and Yes. If Yes, the expansion specified by Distribution and Power/ratio is applied symmetrically from each end of the region


▪ Edit all regions: This displays a dialog which shows all the region settings in a particular direction and allows them to be changed. This is where the Auto-meshing parameters can be adjusted


1.2 Domain Attributes MenuModels

▪ This panel controls the variables to be solved, and the models used


▪ Equation Formulation

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▪ Equation Formulation

- The main choice is between elliptic, parabolic and fully-developed formulation. Elliptic is the most usual form, as it allows for recirculation.

- There is a further choice of staggered or collocated velocity formulation. In the staggered formulation, velocities are stored at cell face centers, in the collocated form they are stored at cell centers, just like pressure and temperature.

- The staggered form is usually best for Cartesian and polar grids, the GCV collocated for BFC.

- Parabolic performs a marching integration suitable for flows with no recirculation, e.g. developing pipe flows or jet spreading.

- Fully-developed calculations will give the flow rate for a given pressure-drop, or the pressure-drop for a given flow, without any information on how the flow developed

1.2 Domain Attributes MenuModels 2

▪ Single / Multi-Phase


▪ Single / Multi-Phase

This option switches between single and multi-phase operation. If the domain is occupied by a single fluid, which does not change phase, or by several fluids which ARE ALWAYS SEPARATED by solid, the flow can be treated as single phase. If the fluid changes phase, or there are several MIXED fluids, then the flow must be treated as multi-phase.

The available options are:

• One phase only one phase present (or several completely separated fluids).

• IPSA Full.This solves the full momentum equations for two phases, allowing for inter-phase heat and mass transfer.

• IPSA Equal vel. This assumes that the velocities of the two phases are always equal, but allows inter-phase heat and mass transfer.

• Algebraic Slip. This solves reduced equations for several dispersed phases in a carrier. Inter-phase heat and mass transfer are not included


▪ Lagrangian Particle Tracker (GENTRA) The particle tracker is an alternative way of treating multi-phase

flows. It is suitable for dilute suspensions, where volume-fraction effects are small. Packets of particles are tracked through the domain. Each packet represents a large number of particles following this path. The particles can exchange heat, mass and momentum with the carrier fluid


▪ Pressure And Velocity This option switches ON or OFF the solution for the pressure

variable P1, and the velocities U1, V1 and W1. If the simulation is two-phase, then the second phase velocities U2, V2 and W2 will also be activated. If the grid dimensionality is changed later, the required velocity component(s) will be added or removed as needed.

Pressure and velocity must be ON before it becomes possible to select Multi-Phase or Free-Surface models


▪ Free Surface Models The available free surface models are: • Scalar equation • Height of liquid The Scalar Equation Method (SEM) is good for overturning or

breaking interfaces, but is restricted to very small time steps. Height of Liquid (HOL) can run steady-state, or with larger time

steps but cannot deal with overturning interfaces


▪ Energy Equation The energy equation can be solved in one of two forms: • Temperature (TEM1/TEM2), or • Enthalpy (H1/H2) The enthalpy form is often more suited to combustion

applications, the temperature form to conjugate heat transfer. Internally, the equation is always cast in enthalpy form, so the units of the sources are always Watts


▪ Energy Equation, Total/Static

By default, the Temperature form is set to 'Total', the enthalpy form to 'Static'. The static form includes the substantial derivative of the pressure and the kinetic heating terms in the energy conservation equation as additional source terms, the Total form does not.

If the flow is highly compressible (high Mach number) the Temperature form should be switched to 'Static' otherwise incorrect solutions will be obtained. This is because all the property formulae require the static temperature.

The Enthalpy form can be used in 'Total' form as long as a suitable temperature derivation is selected in the properties panel


▪ Turbulence Models


▪ Turbulence Models The available turbulence models are divided into the following

groups:• LAMINAR - The flow is laminar and there is no turbulence

model.

• CONSTANT-EFFECTIVE - The turbulent viscosity is constant. The default setting is 200 times the laminar viscosity.

• LVEL - Generalised length-scale zero-equation model, useful when there are many objects and the grid is coarse.

• KEMODL - Classical two-equation high Reynolds number. k- model

• KOMODL - Kolmogorov-Wilcox two- equation k-f model. Useful for transitional flows and flows with adverse pressure gradients.

• USER - User-defined model for advanced users.



• KE Variants - Several variants of the K-E model usually giving enhanced performance for recirculating flow.

- KECHEN - Chen-Kim two-equation k- model. Gives better prediction of separation and vortexes.

- KERNG - RNG derived two-equation k-e model. Gives better prediction of separation and vortexes. However, the user is advised that the model results in substantial deterioration in the prediction of plane and round free jets in stagnant surroundings.

- KEMMK - Murakami, Mochida and Kondo k-e model for flow around bluff bodies as encountered for example in wind-engineering applications.

- KEKL - Kato-Launder k-e model for flow around bluff bodies as encountered for example in wind-engineering applications.

- KEMODL-YAP - k-e model with Yap correction for separated flows.

- TSKEMO - Two scale k-e model for flows in which there is an appreciable time lag between the turbulent production and dissipation processes



• Low-Re models - Several Low-Re Number variants of the K-E model:

- KEMODL-LOWRE - Lam-Bremhorst low Reynolds version of k-.

- KEMODL-LOWRE-YAP - Lam-Bremhorst low Reynolds k- with Yap correction for separated flows.

- KECHEN-LOWRE - Low Reynolds variant of Chen-Kim model.

- KEMODL-2L - Two layer k- model, which uses the high-Re k- model only away from the wall in the fully-turbulent region, and the near-wall viscosity- affected layer is resolved with a one- equation model involving a length-scale prescription. This saves mesh points and improves convergence rates.

- KOMODL-LOWRE - Low Reynolds Kolmogorov-Wilcox model



• Others - A range of models, from simple one-eq. models to Re Stress (REYSTRS), including a Sub-Grid-Scale LES model (SGSMOD):

- MIXLEN - Prandtl mixing-length model. Simple model for unbounded flows.

- MIXLEN-RICE - Mixing-length model for bubble-column reactors.

- KLMODL - Prandtl energy model. One-equation k-l model for wall-dominated flows.

- KWMODL - Saffman-Spalding two-equation. k-vorticity model

- REYSTRS - Reynolds stress model - SGSMOD - Smagorinsky sub-grid scale LES model

with wall damping

- SGSMOD-NOWD - Smagorinsky sub-grid scale LES model with no wall damping

- SGSMOD-VDWD - with Van Driest wall damping function

- 2FLUID - Two-fluid model - MFLUID - Multi-fluid model


▪ Radiation Models The available radiation models are:• IMMERSOL provides an economically-realisable

approximation to the precise mathematical representation of radiative transfer

• 6-Flux (Composite-Flux Model): the discretisation of angle is such that the effects of radiation are accounted for by reference to the positive and negative radiation fluxes in each of the coordinate directions

• Radiosity represents the average of the incoming and outgoing radiation fluxes over all directions of the solid angle


▪ Combustion Models


▪ Combustion Models The following combustion models are available:

• 3 GASES - Simple Chemically-Reacting System (SCRS), mixing controlled or kinetically controlled

• 7 GASES -Extended SCRS

• Wood - Wood combustion model

• Coal - Coal combustion model

• Oil - Oil combustion model

• Chemkin - Interface to Sandia Labs CHEMKIN program


▪ Solution Control / Extra Variables


▪ Solution Control / Extra Variables This panel gives options to:

• Activate storage of user-named variables

• Activate solution of user-named variables

• Set the solution control switches (SOLUTN command) for all stored and solved variables. The settings are: Store, Solve, Whole-field, Point-by-point, Explicit, Harmonic

• Set the terms in the equation for each variable (TERMS command). The settings are: Built-in source, Convection, Diffusion, Transient, Phase 1 variable, Interphase transfer


1.2 Domain Attributes MenuProperties

▪ This panel controls the materials and properties


▪ Use property tables The main domain material can be chosen from the property libraries

1

▪ Use property tables Turning the Use property tables OFF allows the individual

properties to be set directly

1.2 Domain Attributes MenuProperties 2

▪ Domain Material The individual properties loaded from the library for the domain

fluid can then be edited - changed


▪ Domain Material Gases:


▪ Domain Material Liquids:


▪ Domain Material Solids:


▪ Domain Material Other Materials:


▪ Edit properties of current material For each property, a pull-down list of all available options is

provided


▪ Reference pressure and Reference temperature These values are always added to the calculated pressure and

temperature before use in property calculations


▪ Property storage Allows the field values of the properties to be placed in the EARTH

output file PHI, so that they can be plotted in the viewer


PIL variable SI units Nature

RHO1 kg/m**3 first-phase density

DRH1DP m**2/Newton proportionate change with pressure

RHO2 kg/m**3 second-phase density

DRH1DP m**2/Newton proportionate change with pressure

ENUT m**2/s kinematic turbulent contribution to effective viscosity

ENUL m**2/s kinematic laminar (reference) viscosity

PRNDTL(indvar) > 0

dimensionless the Prandtl or Schmidt number

PRNDTL(indvar) < 0

dimensionless or watts/(m*degC)

if indvar is enthalpy or temperature

PRNDTL(indvar) < 0

m**2/s if indvar represents another scalar

PHINT(indvar)

according to indvar equilibrium interface value for the first phase

PHINT(indvar)

according to indvar equilibrium interface value for the second phase

TMP1 degCelsius temperature when first-phase enthalpy is solved for

TMP2 degCelsius temperature when second-phase enthalpy is solved for

1.2 Domain Attributes MenuLists the properties used in PHOENICS 1

▪ Property storage Allows the field values of the properties to be placed in the EARTH

output file PHI, so that they can be plotted in the viewer

PIL variable SI units Nature

EL1 m first-phase turbulence length

EL2 m second-phase turbulence length

CP1 joule/(kg*degC) constant-pressure specific heat of phase 1

CP2 joule/(kg*degC) constant-pressure specific heat of phase 2

DVO1DT 1/degCproportionate change of first-phase specific volume (i.e. reciprocal of density) with temperature

DVO2DT 1/degCproportionate change of second-phase specific volume (i.e. reciprocal of density) with temperature

EMISS 1/mabsorptivity = proportion of radiation which is absorbed per unit length

SCATT 1/m proportion of radiation which is scattered per unit length

CFIPS Newton*s/m**4momentum-transfer rate from one phase to another per unit volume and per unit of velocity difference

CMDOT kg*s/m**4 mass-transfer rate per unit volume and per unit of velocity difference

CINT(indvar)

dimensionlessratio of exchange coefficient to inter-phase friction factor for first-phase side of interface

CINT(indvar)

dimensionlessratio of exchange coefficient to inter-phase friction factor for second-phase side of interface

CVM dimensionless virtual-mass coefficient for two-phase flow.

1.2 Domain Attributes MenuLists the properties used in PHOENICS 2

1.2 Domain Attributes MenuInitialisation

▪ This panel provides options to:

• Activate a restart run


▪ This panel provides options to:• Set all initial values to default. This is 1.0E-10 for all variables

except: - R1,R2, RS : 0.5 - EPOR, NPOR, HPOR, VPOR : 1.0 - PRPS : -1.0


▪ This panel provides options to:• Set individual whole-domain initial values for all stored and

solved variables


▪ This panel provides options to:• Start the In-Form editor with Group 11 selected as the current

Group


▪ This panel provides options to: Unless explicitly set in this panel, initial values for Temperature,

Enthalpy, turbulence model quantities and solved-for passive scalars will be taken from the inlet values supplied at the first inlet defined


▪ This panel provides options to:• Activate a restart run • Set all initial values to default. This is 1.0E-10 for all variables

except: - R1,R2, RS : 0.5 - EPOR, NPOR, HPOR, VPOR : 1.0 - PRPS : -1.0

• Set individual whole-domain initial values for all stored and solved variables

• Start the In-Form editor with Group 11 selected as the current Group Unless explicitly set in this panel, initial values for Temperature,

Enthalpy, turbulence model quantities and solved-for passive scalars will be taken from the inlet values supplied at the first inlet defined


1.2 Domain Attributes MenuSources

1


▪ This panel allows the creation of whole-domain sources, which are not attached to an object. All sources or boundary conditions which do not apply to the whole domain must be attached to an object, and set through the object attribute dialog box

2

▪ Gravitation forces


▪ Cyclic boundary conditions button gives the options:

• Turn cyclic boundaries ON for all IZ slabs • Turn cyclic boundaries OFF for all IZ slabs • Turn cyclic boundaries on and off for individual slabs


▪ Moving Bodies (MOFOR)

1.2 Domain Attributes MenuSources 1

▪ Moving Bodies (MOFOR)• The MOFOR ON/OFF button activates the Moving Frames Of

Reference model, which allows objects to move through the domain. When turned ON, two extra buttons are displayed. One allows the user to browse for the MOF file, and the other to edit it using the currently-selected file editor. The MOF file controls the motion of the objects.

• MOFOR buttons only appear for Transient cases

1.2 Domain Attributes MenuSources 2

▪ Rotation speed for rotating coordinate system• Rotation causes the rotation of the plot about an arbitrary axis

in 3D • The axis may be specified in the same way as for VIEW and UP;

angles are in degrees, and may be positive or negative


▪ Potential flow "Potential flow", also called "ideal-fluid flow" or "irrotational

flow", is a mathematical concept to which real flows approximate only in special circumstances, namely those in which:

• the flow is steady; • viscous effects are absent; and • compressibility effects are small


1.2 Domain Attributes MenuNumerics

▪ The main entries on this panel allow the total number of iterations (sweeps) over the whole domain, and the global convergence criterion to be set


▪ Relaxation Settings

1

▪ Relaxation Settings Relaxation is a technique for slowing down possibly excessive rates of change. It does not affect the final solution.

• The default relaxation settings turn the Automatic Convergence Control ON.

• MAXINC sets the maximum increment from iteration to iteration for each variable.

• The DTFALS settings for velocities are ignored - the solver will set linear relaxation of 0.5 for all velocities

• Reset solution defaults resets all the solver control variables to their default values, so that the Automatic Convergence Control can operate in full

1.2 Domain Attributes MenuNumerics 2

▪ Relaxation Settings

If the Automatic Convergence Control is turned OFF, the relaxation settings can be set individually

• Typical values for DTFALS may be estimated from the governing time-scale of the process under consideration. Very often, values based on residence time work well

• For the velocity variables, it can be advantageous to use the Self-Adjusting Relaxation AlgoritHm (SARAH). This is activated by setting SARAH to a value > 0. Values in the range 0.001 - 0.01, typically 0.005, have been found to work well


▪ Iteration Control


▪ Iteration Control The default linear equation

solver is based on Stone's Strongly Implicit method. To use the Conjugate - Residuals - Gradient solver for any variable, set ENDIT for that variable to GRND1. Circumstances under which this may be advantageous include:

• Pressure correction equation (P1) in buoyancy-driven flows, especially with complex geometry; and

• Temperature (TEM1) in complex conjugate heat transfer cases (except when PARSOL is active)


▪ Limits on Variables


▪ Limits on Variables

This panel allows minimum and maximum values for all SOLVEd and STOREd variables to be set


▪ Differencing Schemes


▪ Differencing Schemes By default, the selected

differencing scheme applies to all SOLVEd variables. The default scheme is the HYBRID scheme


▪ Differencing Schemes

Set schemes individually allows the selection of different schemes for different variables


▪ MIGAL The MIGAL multi-grid convergence accelerator can be used for the

hydrodynamics, the k-e based turbulence models, the energy equation and individual scalars


▪ MIGAL

MIGAL dialog (MIGAL OFF)


▪ MIGAL MIGAL dialog (MIGAL ON)

Settings button leads to a dialog from which all the MIGAL controls can be set


1.2 Domain Attributes MenuGROUND

▪ This panel sets special variables for use in GROUD. The switch for PLANT is also on this panel

1.2 Domain Attributes MenuOutput 1

1.2 Domain Attributes MenuOutput

▪ Output panel gives options to:

• Set the monitoring cell location in terms of cell numbers.

• Set the monitoring cell location in terms of physical space. The nearest cell is chosen as the monitor cell.

• Control the solver end-of-run behaviour.

• Control the solver convergence monitoring output

• Set field print out controls.

• Select the frequency of field-dumping in terms of sweeps for steady-state cases, or time-steps for transient cases, and select which variables are written to the save file.

• Activate storage of derived quantities and print-out of wall function information.

• Activate the calculation and printing of forces on objects.

• Start the In-Form editor with Group 20, 21, 22, 23 or 24 selected as the current Group

2

This has three settings:

• Default - obey the settings in CHAM.INI

• On - always stop at the end of the run and wait for OK, whatever is in CHAM.INI

• Off - never stop at the end of the run, whatever is in CHAM.INI

▪ Pause at End of Run


The solver can display convergence-monitoring information on the screen as graphs of:

• Spot values and residuals vs. sweep (the default)

• Minimum and maximum field values vs. sweep

• Maximum absolute correction and residual vs. sweep

▪ Monitor Graph Style


The settings for OUTPUT are:

1. Field print-out

2. Correction-equation monitor print-out

4. Whole-field residual print-out

5. Spot-value table and/or plot

6. Residual table or plot

▪ Field Printout


▪ Dump Settings


▪ Dump Settings This controls the sweep (for steady-state) or time-step (for transient) frequency with which flow fields are written to disk file. The setting for OUTPUT for each variable determines whether that variable is written to the saved file or not. This can potentially save a lot of disk space by only writing the variables of real interest, but would also prevent such a 'thinned-out' file from being used as an Earth restart file.

In transient cases, intermediate flow fields can be dumped at regular time-step intervals


▪ Derived Variables


▪ Derived Variables Placing the Skin friction coefficient, Stanton Number, Shear stress (actually friction velocity squared, equivalent to shear stress divided by density), Yplus (non-dimensional distance to the wall) and heat transfer coefficient (in W/m2/K) into 3-D storage allows them to be plotted in the Viewer or PHOTON, as well as appearing in the RESULT file.

Note that the heat-transfer coefficients are only calculated for turbulent flow. To make them appear for laminar cases, the turbulent viscosity should be set to a very small value - say 1.0E-10. The Stanton Number must be stored for the heat-transfer coefficients to be calculated.

The friction force components SHRX, SHRY and SHRZ are used in the force-integration routines to add the friction force to the pressure force acting on each object. If they are not stored, the integrated force will only contain the pressure component.

The Total or Stagnation Pressure (PTOT) is only calculated if the Mach Number is stored. If the Reference Pressure is set to zero, the total pressure may go below zero, leading to an error-stop


▪ Forces on Objects When this is 'On', the Earth solver will integrate the pressure

forces over all objects and print the force information to the RESULT file. If the friction force components (SHRX, SHRY and SHRZ) have been placed in 3D store, the force integration will include them

The moments about the X, Y and Z axes are calculated, and the point of action of the force is deduced


• In the VR-Editor, all geometrical features are represented by objects. They may represent for example: blockages, inlets, outlets or heat sources. Complex objects can often be represented by suitable combinations of simpler objects.

• Objects can be volumes or areas, but never lines. Even in a two-dimensional case, PHOENICS requires a depth in the third dimension, or in a one-dimensional case, width and depth. This is because of the finite-volume numerical solution method

• Objects are manipulated via the Object Management Panel (OMP), which is reached by:

- clicking on the button on the hand set;

- clicking on the icon on the toolbar; or,

- clicking Settings - Object attributes from the Top Menu bar

1.3 Object Management Panel 1

▪ Object Management Dialog• The OMP contains a list of the object names along with associated

key data for each object . By default the objects are sorted by their reference number, column two. They may also be sorted by name, type, geometry or colour by clicking on the appropriate column header. The colour number listed is the palette entry for the first facet in the geometry file


▪ Object Management Dialog

• The OMP has four pull-down menus which enable objects to be created, updated or deleted. The updating and deleting actions are performed on all the selected objects. Each column also has its own context menu, displayed by right-clicking in the column.

• Object Menu, Action Menu, View Menu, Group Menu, Context Menu


▪ Object Management - Object Menu

1.3 Object Management PanelObject Menu

1

• New Object Creates a new object at the origin and opens the Object Dialog for it

• Import ObjectCreates a sequence of objects from the contents of a POB file. The first object is always an ASSEMBLY object, which acts as a 'container' for the component objects

• Copy Object(s)This makes a copy of the selected object(s), including all attributes.

Objects and active groups can also be duplicated by clicking on the Duplicate Object or Group button of the hand-set

• Array Object(s) Arraying is a variation on duplication. It allows the creation of an entire array of objects or groups, all copied from the original

• Select All Selects all objects (except the domain) in the object management panel.

• RefreshIt is possible for the object management to become out of sync with the current status of the model, in these cases use refresh to update its contents

• CloseCloses the object management panel

1.3 Object Management PanelObject Menu

2

▪ Object Management - Action Menu

1.3 Object Management PanelAction Menu

1

• Open object dialogThis opens the object dialog box for the current object. The current object is the one highlighted in the list. If more than one object has been selected, the dialog box for the last object to be selected is opened. When the object dialog is closed, the changes made can be optionally propagated through all the other selected objects which are of the same type

• Hide object(s) This hides (makes invisible) all the currently selected objects

• Reveal object(s) This reveals (makes visible) all the currently selected objects

• Delete object(s) This deletes all the currently selected objects. The user will be prompted for confirmation before objects are deleted

• Modify colour Opens the object dialog for the current object on the options page; click on the object colour button to modify the colour. The object transparency may also be set from here. When the object dialog is closed the colour changes will be applied to all selected objects

• Objects affects gridObjects interact with the computational mesh. Turning the mesh toggle on the hand-set ON causes the current grid to be displayed on the image


2

• Object constrained by domainBy default, objects cannot pass through the faces of the domain. Similarly, the domain cannot be made smaller than the largest object. But sometimes it can be convenient to allow objects to partially lie outside the domain - for example to model one half of a body

• Surface contours (Viewer only)Check menu item toggles whether surface contours are displayed on the current items

• Dump surface values (Viewer only if Surface contour ticked)• Dump object profile (Viewer only if Surface contour ticked) • Show results (Viewer only)

Displays sources and sinks for the selected object in a pop-up window. The values are read from the 'Sources and sinks' section of the RESULT file. Force and moment data for blockages is also displayed if present.


3

▪ Object Management - View Menu• The first seven check menu

entries indicate whether the corresponding column is visible in the listbox. The final check menu item 'Assembly objects' indicates whether the child assembly objects are visible in the list of objects

1.3 Object Management PanelView Menu

▪ Object Management - Group Menu

1.3 Object Management PanelGroup Menu

1

▪ Object Management - Group Menu• Save

When more than one object is selected, a temporary group is created. This group may be saved to be recalled later by using this option. Any saved group will subsequently be listed in the list of objects in the object management panel. Details of any saved groups will be written to the Q1

• Delete If the current object is a saved group then this option becomes active and may be used to delete the group

• ModifyThis option may be used to modify the membership of a saved group

1.3 Object Management PanelGroup Menu

2

▪ Object Management - Context Menu

1.3 Object Management PanelContext Menu

1

▪ Object Management - Context Menu• The context menu is an extension to the Action menu. The items in the menu depend on the column. It enables the rapid selection of objects of a single type or geometry, and also provides a shortcut access to the geometry generation program Shapemaker.

• A similar context menu is accessed by right-clicking on an object in the graphics window.

• The context menu for the 'Reference' column is different from the others - it allows the sequence number of the selected object(s) to be changed

1.3 Object Management PanelContext Menu

2

Object Type Brief DescriptionBlockage 3D, solid or fluid. Can apply heat and momentum sources.

Inlet 2D, fixed mass source.

Angled-in 3D, fixed mass source.

Wind_Profile 2D, fixed mass source following atmospheric boundary layer.

Outlet 2D, fixed pressure.

Angled-out 3D, fixed pressure.

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.

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

1.4 Object Types and Attributes

1.5 The VR Editor Control Panel

• Movement Controls

• Domain and Object Controls

1.5 The VR Editor Control Panel

2. VR Viewer

• Vectors - click on the 'Vector toggle' . Vectors are colored by the current plotting variable, but their length is always related to the absolute velocity.

• Contours - click on the 'Contour toggle'

• Streamlines - click on the 'Streamline management' button

• Iso-surfaces - click on the 'Iso-Surface toggle'

• To select Pressure - click on the 'Select Pressure button'

• To select Velocity - click on the 'Select Velocity button'

• To select Temperature - click on the 'Select Temperature button'

• To select any other variable - click on the 'Select a Variable’

• To view:

• To select the plotting variable:

1

• To change the direction of the plotting plane, set the slice direction to X, Y or Z

• To change the position of the plotting plane, move the probe using the probe position buttons

• Alternatively, click on the probe icon on the toolbar or double-click the probe itself to bring up the Probe Location dialog

2. VR Viewer 2

Chapter 3Chapter 3

PHOENICS Application Example

“Simulation of Contaminant Flow”

• Geometry of flow

The flow is two-dimensional

Simulation of Contaminant Flow

Pre-Processor VR-Editor

1

Pre-Processor VR-Editor

2

Main Solver Earth

Post-Processor VR-Viewer

THE ENDTHE END

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