Transcript Computer Aided Thermal Fluid Analysis Lecture 2

Computer Aided Thermal Fluid
Analysis
Lecture 2
Dr. Ming-Jyh Chern
ME NTUST
Road Map for Today
• How to initialize STAR-CD?
• Four major modeling processes.
• Usage of SET
• Generation of Vertices
prostar - Exceed
• STAR-CD was coded under an X-window
environment.
• To run STAR-CD in MS Window, a program
to transform images given by STAR-CD is
necessary.
• Exceed is able to reach this goal. You
need to run exceed before the usage of
STAR-CD.
STAR-CD Launcher
prostar - Exceed
prostar
Command Window
STAR-GUIDE
Quit from STAR-CD
Four Major Modeling
Process
• Phase 1 – Working out a modeling
strategy
• Phase 2 – Preprocessing - Setting up the
flow model using PROSTAR
• Phase 3 – Solver - Performing the flow
analysis using STAR
• Phase 4 – Post-processing the results
using PROSTAR
Phase 1 – Working out a
Modeling Strategy
• Planning the computational mesh
• Looking up numerical values for
appropriate physical parameters
• Choosing the most suitable modeling
option from what is available.
Phase 2 – Setting Up the
Flow Model Using
Prostar
• Creating a computational mesh to represent the flow
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domain.
Specifying the thermophysical properties of the fluids
and/or solids.
Setting the solution parameters and output data formats.
Specifying the location and definition of boundaries and
time increment.
• Writing appropriate data files.
Phase 3 – Performing the
Flow Analysis Using
Prostar
• Reading input data created by Prostar and,
if dealing with a restart run, the results of
a previous run.
• Judging the progress of the run by
analysing various monitoring data and
solution statistics provided by STAR.
Phase 4 – Postprocessing the results
Using Prostar
• Display and visualize the obtained results.
• Plot velocity vector fields.
• Plot contours regarding pressure, density
and so on.
• Plot curves regarding variation of flow
fields.
STAR-CD System
Structure
Pro-STAR
STAR
Files in STAR-CD
Usage of Mouse
• Left bottom – Rotation
• Middle bottom (or Left+Right bottoms) –
Zoom
• Right bottom - Move
Basic Elements
• Cell
• Vertex
• Boundary
• Block
• Couple
• Spline
• Droplet
Concept of Set
• Every command or action in STAR-CD
only affects elements in a set. Before
you give a command, you’d better
select the elements which you want to
modify.
• The range of a set can be checked via
“List” in Prostar.
When set is used?
• Plot results
• Establish model
• Check model
• Post-processing
Common sets
• cset: Cell set
• vset: Vertex set
• bset: Boundary set
• splset: Spline set
• Blkset: Block set
Coordinates
• Global coordinate
• Local coordinate
• Cartesian coordinate
• Cylindrical coordinate
• Spherical coordinate
Coordinates
• Change or view setting of coordinate
system from STAR GUIde.
• Create and Import Geometry->Create
Geometric Entities-> find vertices in the
yellow part-> click the icon near
“Current Coordinate System”
Coordinates
Current
system
Command For Vertex
Generation
• Before you generate a vertex, you’d
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better to check which coordinate you
use.
v,1,0,0,5
v,2 ,10,0,0
vset,all
vplot
Alternative Way to
Generate a Vertex
Vertex List
• Find vertex list from the item “Vertices” of
“Lists” in Prostar
Vertex Tool
• Find vertex tool from the item “Vertex Tool”
of “Tools” in Prostar
Vertex Tool