ANSYS CFX S3 PreProcess, Solve

1
ANSYS CFXS3 Pre-Process, Solve Post-Process

• Maryam Einian
• mae345_at_mail.usask.ca
• CFD lab 1B85

2
Numerical Simulation
Pre-Processor
Geometry
Solver
Post-Processor
Meshing
CFX-Pre
3
ANSYS Workbench CFX-Pre

• ANSYS Workbench
• Select a Mesh File --gt .cmdb
• Advanced CFD Tasks
• Create CFD Simulation with Mesh
• Examine in CFX-Post
• CFX-Pre

4
CEX-Pre Mesh

• Automatically Uploaded
• Import Mesh
• Principal 3-D Regions
• Principal 2-D Regions
• Edit Definition
• Edit Mesh
• Statistics

5
CFX-Pre Quick Setups (Gen/Turbo)

• Quick Setup Mode
• Very Simple Problems
• Set Boundary Conditions before-hand
• Turbo Mode
• Pump, Fan, Compressors, Turbines
• Set Boundary Conditions before-hand
• Set Domains and Coordinate Systems before hand

6
CFX-Pre General Overview

• Simulation Type
• Details of Domain
• Boundary Conditions
• Solver Set-ups

7
CFX-Pre Simulation Type

• External Solver Coupling
• None
• ANSYS Multifield Structural, Electro-Magnetics
• ANSYS Multifield via Prep 7
• Simulation Type
• Steady State
• Transient

8
Details of Domain General Options

• Basic Settings
• Location 3D regions--gt Multi-Domain Problems
• Domain Type Fluid/Solid/Porous
• Fluids List Various Materials
• Coord Frame
• Domain Models
• Reference Pressure Absolute Press--gtVacuum
• Buoyancy Gravity--gtBuoyant Plumes, Ships
• Domain Motion Stationary/Rotating--gtPumps/Turbo-Ma
  chinery
• Mesh Deformation Varying Geometry/Moving Walls
  --gt Expansion

9
Details of Domain Fluid Models-Initialisation

• Heat Transfer
• None incompressible flows
• Isothermal constant temp
• Thermal Energy low-speed flows
• Total Energy high-speed energy effects
• Turbulence- Near Wall Modeling
• None (Laminar) Laminar flows
• K-Epsilon Most Popular
• Shear Stress Transport Advanced
• BSL Reynolds Stress Advanced
• SSG Reynolds Stress Advanced
• Reaction or Combustion
• Thermal Radiation Model
• Initialisation

10
Boundary Conditions

• Inlet Flows into the Domain
• Flow Regime (Subsonic/Supersonic/Mixed)
• Mass and Momentum, Turbulence Intensity, Heat
  Transfer
• Initialise Profile Date
• Outlet Flows out of the Domain
• Flow Regime (Subsonic/Supersonic)
• Mass and Momentum, Pressure Averaging
• Opening Flows both into and out of the Domain
• Flow Regime (Subsonic)
• Mass and Momentum, Pressure, Turbulence, Heat
  Transfer
• Wall Slip/No-Slip Walls
• Slip/No-Slip, wall Velocity
• Smooth/Rough
• Heat Transfer
• Symmetry Geometric and Flow Symmetry
• General for all boundary types (Location,
  Sources, Plot options)

11
Solver Set-ups

• Basic Settings (units)
• Solver Control
• Output Control
• Mesh Refinement (Adaptation Option)
• Expert Parameters

12
Solver Setups Solver Control

• Advection Scheme (CDS, UDS, Hybrid)
• Maximum Number of Iterations
• Fluid Time Scale Control ?t
• Convergence Criteria
• Residual Types RMS (Root Mean Square), Max
• Residual Target xE-Y
• Equation Class
• Advanced Options

13
CFX-pre Finalize

• Additional Variables
• Expressions
• User Functions
• User Routines

• Write Solver File
• CFX-Pre --gt CFX-Solver

14
Simulation Type

• External Solver Coupling
• None
• Simulation Type
• Steady State

ANSYS-CFX Website
15
Details of Domain General Options

• Basic Settings
• Location B82
• Domain Type Fluid Domain
• Fluids List Air at 25 C
• Coord Frame Coord 0
• Domain Models
• Reference Pressure 1 atm
• Buoyancy Non Buoyant
• Domain Motion Stationary
• Mesh Deformation None

16
Details of Domain Fluid Models - Initialisation

• Heat Transfer None
• Turbulence K-Epsilon
• Near Wall Modeling Scalable
• Reaction or Combustion
• Thermal Radiation Model

• No Domain Initialisation

17
Boundary Conditions

• Inlet Inlet
• Flow Regime --gt Subsonic
• Mass FR --gt 0.1 m/s
• Direction --gt Normal to BC
• Turbulence Intensity --gt Medium
• Outlet Outlet
• Flow Regime --gt Subsonic
• Mass FR --gt 0.1 m/s
• TB Wall
• Free Slip
• Plate Wall
• No-slip
• Smooth Wall
• Side Walls Symmetry

18
Solver Setups Solver Control

• Advection Scheme Upwind
• Max. Iterations 50
• Fluid Time Scale Control
• Time Scale Control Auto Time Scale
• Time Scale Factor 1.5
• Convergence Criteria
• Residual Types RMS (root mean square)
• Residual Target 1.E-5

19
CFX-Pre --gt CFX-Solver

• Save
• Export CCL (CFX Command Language)
• Write Solver File

20
CFX-Solver

• Definition File Automatically Uploaded
• Initial Values File If Available (Resume)
• Adaptation Database
• Type of Run
• Full
• Partitioner Only For Parallel Solvers
• Parallel Environment Run Mode
• Serial
• PVMs Parallel Virtual Machine
• MPIs Message Passing Interface

21
CFX-Solver

• Out File
• Residuals
• Equations
• Mass and Momentum (3 Momentum (x,y,x) 1
  Mass)
• Turbulence (KE) (1 ? and 1 e eq.)
• Modes
• RMS
• MAX

22
CFX-Post

• Select a Surface
• Color Variable Mode
• Variable Pressure, Velocity,
• Range Global/Local
• Color Scale Linear
• Color Map Rainbow
• Apply

22
23
CFX-Post Create Locations

• Geometric Locations (X,Y,Z)
• Point, Point Cloud
• Line
• Plane
• Volume
• Geometric and Flow Locations
• Isosurface
• Surface of Revolution
• Polyline
• User Surface

24
CFX-Post Visual Options

• Domain
• Location
• Range
• Sampling
• Reduction Factor
• Variable

• Vector
• Contours
• Streamlines

25
CFX-Post Define Exp.-Var.

• Insert Expression
• Functions
• CFX-Post
• CEL
• Expressions
• Variables
• Locations
• Constants

• Insert Variable
• Methods
• Expression
• Frozen Copy
• Dimensions
• Scalar
• Vector (3D)

26
CFX-Post Tables-Charts

• Insert Chart
• Type
• Regular
• From File
• Location
• X Axis Variable
• Y Axis Variable
• Conservative (original)
• Hybrid (recalculated)

• Insert Table
• Functions
• CFX-Post
• CEL
• Expressions
• Variables
• Locations
• Constants
• Export File .csv
• Export Geometry
• Select Variables

27
CFX-Post Tools

• Probe
• Function Calculator
• Macro Calculator (Turbo)
• Mesh Calculator

28
CFX-Post

• Plate
• Color
• Mode Variable
• Variable Pressure
• Range Global/Local
• Color Scale Linear
• Color Map Rainbow
• Apply

28
29
CFX-Post Create Locations

• Insert Locations
• Line
• Method (Two Points)
• Point1 (8,0,5) Point2 (8,10,5)
• Sample 200
• Plane
• Method (XY Plane)
• Z (5 m)
• Isosurface
• Variable (Pressure/Velocity)
• Value (1E-4)

30
CFX-Post Visual Options

• Vector
• Locations (Plane 1)
• Sampling (Equally Spaced)
• of Points (200)
• Variable (Velocity)
• Contours
• Locations (Plane1)
• Variable (Pressure/Velocity)
• Range (Global/Local)
• of Contours (20)
• Streamlines
• Type (Surface Streamlines)
• Surfaces (Plane 1)
• Start From (Locations/Inlet)
• Reduction (Max Number of Points)
• Variable (Velocity)

31
CFX-Post Define Exp.-Var.

• Press Coefficient

• Insert Expression CPEXP
• (Pressure Variables - Reference Pressure
  Expressions)
• /(Density Variables(Mass Flow CFX-Function _at_
  inlet Locations /Area CFX-Function _at_ Inlet
  Locations)2)
• Insert Variable CP
• Method Expression
• Scalar
• Expression CPEXP

32
CFX-Post Tables-Charts

• Insert Chart
• Type Regular
• Location Line 1
• X Axis Variable Velocity
• Y Axis Variable Y
• of Samples for the Line
• 10 ----gt 200

• Export File .csv
• File Out.csv
• Type Generic
• Location Line1
• Boundary Values Hybrid
• Export Geometry Info
• Grid Info (Line/Face Con-Node )
• Select Variables (Velocity/Pressure)