# Presentation: 004626

- NPARC Flow Simulation System

## What is NPARC?

- The NPARC (**N**ational **P**roject for **A**pplication-Oriented **R**esearch in **C**FD) Alliance is a partnership between NASA GRC and the U.S. Air Force AEDC, with significant participation from Boeing, dedicated to providing an applications-oriented computational fluid dynamics (CFD) capability for the U.S. aerospace community, centered around the NPARC Flowfield Simulation System.
- The NPARC Vision:
- 	     *The Computational Tool of Choice for Aerospace Flow Simulation*

## 1993	• Formation of NPARC Alliance
1994-96	• Significant development of NPARC leads to large user base
1996	• McDonnell Douglas becomes an active partner
 	   	• Code development groups at AEDC merge
		• Decide to merge NPARC, NASTD, NXAIR into WIND
1997 	• Work begins on the NPARC Alliance Flowfield Simulation
		      System centered on the WIND Navier-Stokes Code
		• McDonnell Douglas merges with Boeing
1998 	• WIND Version 1.0 released
1999	• WIND Version 2.0 released
		• NASA Software of the Year Honorable Mention winner
2000    	• WIND Version 3.0 released
2001 	• WIND Version 4.0 released
2002	• WIND Version 5.0 released
		• BCFD (unstructured grid version) released to the Alliance

**1994-96**	• Significant development of NPARC leads to large user base
**1996**	• McDonnell Douglas becomes an active partner
-  	   	• Code development groups at AEDC merge
- 		• Decide to merge NPARC, NASTD, NXAIR into WIND
**1997** 	• Work begins on the NPARC Alliance Flowfield Simulation
- 		      System centered on the WIND Navier-Stokes Code
- 		• McDonnell Douglas merges with Boeing
**1998** 	• WIND Version 1.0 released
**1999**	• WIND Version 2.0 released
- 		• NASA Software of the Year Honorable Mention winner
**2000**    	• WIND Version 3.0 released
**2001** 	• WIND Version 4.0 released
**2002**	• WIND Version 5.0 released
- 		• BCFD (unstructured grid version) released to the Alliance

- NPARC Alliance History

## Alliance Organization

- Ted Reyhner
- (Boeing-Commercial)

- Executive
- Direction
- Committee

- AEDC

- GRC

- Jere Matty
- Manager

- Greg Power
- Technical Lead

- Bonnie Heikkinen
- Support Lead

- Chris Nelson
- Development Lead

- Ken Tatum
- Validation Lead

- Mary Jo Long-Davis
- Manager

- Nick Georgiadis
- Technical Lead

- John Slater
- Support Lead

- Charlie Towne
- Development Lead

- Julie Dudek
- Validation Lead

- Technical
- Direction
- Committee

- Technical
- Liaisons

- NPARC Steering
- Committee

- Ray Cosner
- (Boeing - PW)

- Bob Bush
- (UTRC)

## Flow Simulation System

- The *NPARC Flow Simulation System* has at its core the WIND CFD solver, but also consists of...
- common, portable file structure
- pre-processing utilities to set up the simulation
- post-processing utilities for examining the results
- web-based version control software
- web-based documentation
- web-based validation and verification archive
*The NPARC Flow Simulation System assumes that the grid is generated using some other software system (i.e. ICEM CFD, Gridgen).*

## Supported Platforms

-     -  IRIX 6.5, R4400, R5000, R10000, R12000, R14000 processors
-     -  Multi-processing IRIX 6.5, R10000, R12000, and R14000 processors
-   Hewlett-Packard
-     -  Multi-processing HPPA11, PA-8500 processor
-   Sun
-     -  SunOS 5.*x*, SPARC4U processor
-     -  Multi-processing SunOS 5.*x*, SPARC4U processor
-   Linux, X86 processor

## Flow Simulation System

- IVMS

- _WWW_
- Documentation
- Validation

- GMAN

- WIND

- CFPOST

- Grid Generator

- Post-Processor

- Download Code

- Create Grid

- Set Boundary
- Conditions

- Run Flow
-      Solver

- Examine
- Results

- Monitor Convergence

- Convert File Formats
- Mirror Zones
- Split/Merge Zones
- Reorder/Delete Zones
- Wall Function Pre-Processor

## Class Flowchart

**RESPLT**
*(read residuals)*

**CFPOST**
*(plot and process)*

- run.x *(PLOT3D grid file)*

- run.cgd *(common grid file)*

**GMAN**
*(set boundary conditions)*

- run.cgd *(common grid file with BCs set)*

- run.dat *(data input file)*

- run.cfl *(common solution file)*

- run.lis *(list output file)*

- nsl2.gen *(GENPLOT file of NS residuals)*

- run.q *(PLOT3D solution file)*
- output.gen *(output GENPLOT file)*
- output.lis *(output list file)*

**CFCNVT**
*(convert files)*

**WIND**
*(solve flow)*

- run.cfl *(common solution file)*

- run.cgd *(common grid file)*

- run.mpc *(multiprocessor control file)*

*Indicates an optional file*

**Notes:**
This is the flowchart that is the focus of the remainder of the class.  We will discuss in depth the use of the five main programs (cfcnvt, gman, wind, resplt, and cfpost) and the files that are inputs and outputs to each of these programs.

## CFCNVT  
	Converts the PLOT3D grid and solution files (run.x, run.ic.q) into the common file format (run.cgd, run.cfl).
GMAN  
	Reads the common grid file and allows for manipulation of the grid and setting of boundary condition types onto zone boundaries and overlapping regions.
WIND 
	Solves the flow equations with inputs from the common files and input data file.  Outputs the solution to the common solution file and creates a list output file.
RESPLT 
	Reads the list output file and generates GENPLOT files of convergence histories.
CFPOST 
	Post-processor.  Reads the common grid and solution files and lists flow field variables, integrates fluxes and forces, creates and plots line and surface GENPLOT files, creates PLOT3D files, and generates output reports.

- 	Converts the PLOT3D grid and solution files (run.x, run.ic.q) into the common file format (run.cgd, run.cfl).
**GMAN**
- 	Reads the common grid file and allows for manipulation of the grid and setting of boundary condition types onto zone boundaries and overlapping regions.
**WIND**
- 	Solves the flow equations with inputs from the common files and input data file.  Outputs the solution to the common solution file and creates a list output file.
**RESPLT**
- 	Reads the list output file and generates GENPLOT files of convergence histories.
**CFPOST**
- 	Post-processor.  Reads the common grid and solution files and lists flow field variables, integrates fluxes and forces, creates and plots line and surface GENPLOT files, creates PLOT3D files, and generates output reports.

- Primary Parts of the System

## B4WIND  GUI interface for converting NPARC files to WIND common file format
CFBETA   Creates a mirror image of the grid for sideslip (beta) cases
CFCOMBINE   Combines zones of common grid and solution files for which grid points match
CFREORDER   Deletes and reorders zones from the grid or solution file
CFSPLIT   Splits a zone of the common grid and solutions files
FPRO   Performs manipulations of the common solution file
GPRO   Performs grid generation and manipulation
JORMAK   Creates a *.com file containing the solid boundaries for analyzing the surface properties
TIMPLT   Reads a common time history file (.cth) and creates a GENPLOT file
CFSEQUENCE   Extracts a sequence grid and solution from existing files
CFSUBSET   Removes grid points from the log-layer for wall function applications
ADFVIEWER   From the CGNS project, is an ADF file viewer and editor with a nice GUI interface

MADCAP    Replacement for GMAN and a unified GUI for many of these utilities

Plus several more utilities that are listed and explained in the online documentation

- CFBETA   Creates a mirror image of the grid for sideslip (beta) cases
- CFCOMBINE   Combines zones of common grid and solution files for which grid points match
- CFREORDER   Deletes and reorders zones from the grid or solution file
- CFSPLIT   Splits a zone of the common grid and solutions files
- FPRO   Performs manipulations of the common solution file
- GPRO   Performs grid generation and manipulation
- JORMAK   Creates a *.com file containing the solid boundaries for analyzing the surface properties
- TIMPLT   Reads a common time history file (.cth) and creates a GENPLOT file
- CFSEQUENCE   Extracts a sequence grid and solution from existing files
- CFSUBSET   Removes grid points from the log-layer for wall function applications
- ADFVIEWER   From the CGNS project, is an ADF file viewer and editor with a nice GUI interface
- MADCAP    Replacement for GMAN and a unified GUI for many of these utilities
*Plus several more utilities that are listed and explained in the online documentation*

- Other Utilities

## IVMS    

-   Internet Version Management System
-    (IVMS) used for software version
-   control and for distribution of
-   software to users
-   Accessed via the WWW
-   GUI interface based on RCS,
-   developed at Boeing
-   Users can easily download current
-   (and earlier) versions of WIND
-   and its associated utilities
-   Allows collaborative development at
-   multiple sites

## Code Distributions   

- WIND Application Distribution - Contains the executable programs and files needed to run WIND on a specific supported platform.
- WIND Build Distribution - Contains all source code needed to build the code, plus Makefiles for several platforms.
- Tools Distribution - Contains executables for the pre- and post-processing tools used with WIND, including GMAN and CFPOST, for a specific supported platform.  Tools also available individually as source code, with Makefiles.

## Availability   

-   NPARC Alliance software is available at no cost to U. S. companies,
-   government agencies, and universities.
-   May not be used for contract work with a non-U. S. organization.
-   Release point is through AEDC.
-   Non-government organizations must have an Export Control Number,
-    i.e., be registered with the Defense Logistics Services Center Joint
-   Certification Program.
-   See the “Acquiring the Software” link on the NPARC Alliance
-   home page (www.arnold.af.mil/nparc) for details and application
-   forms, or send email to nparc-support@info.arnold.af.mil*.*
-   Approved users download the software from the IVMS web site.

## Source and executables for WIND, and the various tools, are available from zargon via automount (contact Charlie Towne).
Requires setting of environment variables in .login file.
Executables for SGI, Sun, and Linux.
Run without installing on your own system.
Run codes using scripts.
For details see “WIND at NASA Glenn” in the WIND Installation Guide, at http://www.grc.nasa.gov/www/winddocs/install/grc/grc.html
WIND can be installed from tar file of Application distribution.
Installation documentation is available at 
		http://www.grc.nasa.gov/www/winddocs/install

- Requires setting of environment variables in *.login* file.
- Executables for SGI, Sun, and Linux.
- Run without installing on your own system.
- Run codes using scripts.
- For details see “WIND at NASA Glenn” in the *WIND Installation Guide*, at http://www.grc.nasa.gov/www/winddocs/install/grc/grc.html
- WIND can be installed from tar file of Application distribution.
- Installation documentation is available at
- 		http://www.grc.nasa.gov/www/winddocs/install

- WIND Access at NASA Glenn

## Documentation   

*  *All documentation is available at
*  *www.grc.nasa.gov/www/winddocs
-   in both HTML and PDF formats
*  *WIND User’s Guide - Describes the
-   operation and use of the WIND code,
-   including a tutorial, and descriptions of
-   the physical and numerical models,
-   boundary conditions, convergence
-   monitoring, files, run scripts, parallel
-   operation, and input keywords
-   Separate user’s guides for GMAN and
-   CFPOST, and for several smaller
-   utilities distributed with WIND

## Additional Documentation   

- WIND Installation Guide - Describes how to download and install the executables for WIND and its associated “tools,” how to build a new executable from the WIND source code, and how to access WIND via automount* *here at GRC.
- WIND Developer’s Reference - Contains detailed information about the structure of the WIND code useful for those modifying the code (only available to WIND users).
- Common File User’s Guide - Detailed information about the common file library, a set of routines providing access to common files.
- Guidelines Documents - Programming, documentation, and testing guidelines created for use by the NPARC Alliance during software development projects.

## Verification & Validation   

*  *NPARC* *Alliance Verification &
-   Validation (V&V) WWW site at
-   www.grc.nasa.gov/www/wind/valid
* * Validation archive presents WIND code
-   results; all input/output files may be
-   downloaded.
-   Verification cases present comparisons of
-   CFD results with exact analytical or
-   computational results.
-   Validation cases present comparisons
-   of CFD results with high-quality
-   experimental data.
-   Includes detailed examples showing how
-   to set up and run a case, using GMAN,
-   WIND, CFPOST, and other WIND utilities.

## Support   

-   NPARC Alliance Support Team provides direct user support via email
-    (nparc-support@info.arnold.af.mil) or telephone (931-454-7455).
-   National user’s meetings once a year (AIAA Aerospace Sciences Meeting)
-   Dedicated technical paper session (AIAA Aerospace Sciences Meeting)
-   Training classes.
-   Annual newsletter (*The Predictor */ *Corrector*).
-   Annual Workshop produces *Policies and Plans* document.
-   User’s mailing list (nparc-users@info.arnold.af.mil).
-   NPARC Alliance WWW site (www.arnold.af.mil/nparc).
-   Online documentation (www.grc.nasa.gov/www/winddocs).

## Development of WIND and utilities is continuous (Boeing, AEDC, NASA GRC).
GRC efforts focused on developing tool for simulating inlet and nozzle flows (VG model, turbulence, bleed).
Development efforts / contributions / suggestions by users are encouraged for all aspects of the system.
IVMS allows distributed development while maintaining strict version control.

- GRC efforts focused on developing tool for simulating inlet and nozzle flows (VG model, turbulence, bleed).
- Development efforts / contributions / suggestions by users are encouraged for all aspects of the system.
- IVMS allows distributed development while maintaining strict version control.

- Code Development

## Unstructured and hybrid grids.  BCFD was released to Alliance and we will be running cases to learn how to use it.
Enhanced physical modeling capabilities: turbulence, transition, chemically reacting flows, boundary conditions, vortex generators.
Complete conversion to CGNS database format.  Version 5 capability will be tested.
Consolidation of tools under a common GUI (MADCAP).  This will eventually replace GMAN.
Investigate framework options for future CFD systems and multi-disciplinary applications (store-drop, aeroelasticity, structures).

- Enhanced physical modeling capabilities: turbulence, transition, chemically reacting flows, boundary conditions, vortex generators.
- Complete conversion to CGNS database format.  Version 5 capability will be tested.
- Consolidation of tools under a common GUI (MADCAP).  This will eventually replace GMAN.
- Investigate framework options for future CFD systems and multi-disciplinary applications (store-drop, aeroelasticity, structures).

- Future Activities

## Class Flowchart

**RESPLT**
*(read residuals)*

**CFPOST**
*(plot and process)*

- run.x *(PLOT3D grid file)*

- run.cgd *(common grid file)*

**GMAN**
*(set boundary conditions)*

- run.cgd *(common grid file with BCs set)*

- run.dat *(data input file)*

- run.cfl *(common solution file)*

- run.lis *(list output file)*

- nsl2.gen *(GENPLOT file of NS residuals)*

- run.q *(PLOT3D solution file)*
- output.gen *(output GENPLOT file)*
- output.lis *(output list file)*

**CFCNVT**
*(convert files)*

**WIND**
*(solve flow)*

- run.cfl *(common solution file)*

- run.cgd *(common grid file)*

*Indicates an optional file*

- run.mpc *(multiprocessor control file)*

**Notes:**
This is the flowchart that is the focus of the remainder of the class.  We will discuss in depth the use of the five main programs (cfcnvt, gman, wind, resplt, and cfpost) and the files that are inputs and outputs to each of these programs.

## Principal Input Files
Input Data File (*.dat).  Contains keyword input describing the flow problem and how WIND is to be run. (ASCII file)
Common Grid File (*.cgd).  Contains the computational grid (x,y,z) and boundary condition types and zone coupling data set using GMAN. (binary file)
Principal Output Files
List Output File (*.lis).  Contains listing of input parameters, job statistics, error messages, residuals and integrated convergence information. (ASCII file)
Common Flow File (*.cfl).  Contains the flow, turbulence, and chemistry field, as well as reference state and basic information on simulation. (binary file)
Common File Format (CFF) 
Used for common grid (*.cgd) and flow (*.cfl) files.
Also used for some other WIND-related files.
Self-documenting database structure developed at Boeing.
Compact, easily accessible, portable.
Common grid and common Flow files supported by several commercial grid-generation (ICEM, Gridgen) and post-processing packages (Fieldview).
CGNS now supported.

- Input Data File (*.dat).  Contains keyword input describing the flow problem and how WIND is to be run. *(ASCII file)*
- Common Grid File (*.cgd).  Contains the computational grid (x,y,z) and boundary condition types and zone coupling data set using GMAN. *(binary file)*
- Principal Output Files
- List Output File (*.lis).  Contains listing of input parameters, job statistics, error messages, residuals and integrated convergence information. *(ASCII file)*
- Common Flow File (*.cfl).  Contains the flow, turbulence, and chemistry field, as well as reference state and basic information on simulation. *(binary file)*
- Common File Format (CFF)
- Used for common grid (*.cgd) and flow (*.cfl) files.
- Also used for some other WIND-related files.
- Self-documenting database structure developed at Boeing.
- Compact, easily accessible, portable.
- Common grid and common Flow files supported by several commercial grid-generation (ICEM, Gridgen) and post-processing packages (Fieldview).
- CGNS now supported.

- WIND Files

## Other / Optional Input Files
Multi-processor control file (*.mpc) 
Chemistry Input file (*.chm) 
WIND Stop File (NDSTOP)
Transition and temperature specification files

Other / Optional Output Files
Global Newton file (.cfk)
Boundary data file (.tda)
Time history file (.cth) 

Further information is in WIND User’s Guide:
	www.lerc.nasa.gov/www/winddocs/user/files.html

- Multi-processor control file (*.mpc)
- Chemistry Input file (*.chm)
- WIND Stop File (NDSTOP)
- Transition and temperature specification files
- Other / Optional Output Files
- Global Newton file (.cfk)
- Boundary data file (.tda)
- Time history file (.cth)
- Further information is in WIND User’s Guide:
- _[	](http://www.lerc.nasa.gov/www/winddocs/user/files.html)_www.lerc.nasa.gov/www/winddocs/user/files.html

- WIND Files (cont)

## Common File Convert (CFCNVT).
Converts several file formats to the common file format for WIND.
Grid and flow files can be converted.
Flow file can be used as initial  condition for flow field in WIND. 
Text-based program can be run interactively or in batch.
Reply to a few prompts depending on the input file format.
Start analysis process assuming we have a grid file.

- Converts several file formats to the common file format for WIND.
- Grid and flow files can be converted.
- Flow file can be used as initial  condition for flow field in WIND.
- Text-based program can be run interactively or in batch.
- Reply to a few prompts depending on the input file format.
- Start analysis process assuming we have a grid file.

- CFCNVT

- PLOT3D format (option 11) is a common grid file format output by grid generation software.
- An initial flow field can be generated with another small program, output to the PLOT3D format, and then converted to a common flow file using CFCNVT.

## GMAN   

- GMAN

- Grid Manager (GMAN).
- GMAN can be run in interactive mode using graphical menus or commands or in batch mode using scripts.
- Input is the common grid file (*.cgd).
- Switching to graphics mode is done by “swi” or “switch”.
- Journal file is output for rerunning GMAN in batch mode.

- Red boxes indicate inputs to prompts

- What does GMAN do?
-   Set units for grid and flow (EE or SI)
-   Set boundary condition types
-   Display grid and boundary condition types
-   Compute zonal connectivity
-   Perform hole-cutting and grid overlapping
-   Scale, translate, rotate grid
-   Add or replace zone from other file
-   Basic grid generation (*seldom used*)

- The MADCAP program will eventually replace GMAN

## GMAN: Graphics Mode   

- Quick Reference:
- Hierarchy of menu items is from top to bottom.
- Left mouse button selects a menu item.
- A line through a menu item indicates that item can’t be chosen.
- A “*” in front of a menu item indicates that item is the default.
- Mouse Buttons in Display:
- LEFT: Rotation
- MIDDLE: Zooming
- RIGHT: Translation

## GMAN: Boundary Conditions   

- GMAN: Boundary Conditions

- GMAN is used to assign boundary condition types to each grid point on a zonal boundary.
- Zonal boundaries:
- I1,  IMAX,  J1,  JMAX,  K1,  KMAX
- Subregions of boundary grid points can be defined to specify multiple BC types on a zonal boundary.
- Process for specifying BC type:
- Select zone (i.e. zone 1)
- Select boundary (i.e. K1)
- Select subregion (i.e. j1 j21 i2 i14) *optional*
- Select BC type
- Update file

- BC types available:
-    Undefined
-    Reflection
-    Freestream
-    Viscous wall
-    Arbitrary Inflow
-    Outflow
-    Inviscid Wall
-    Self-Closing
-    Singular Axis
-    Mixed-Axis Wall
-    Bleed
-    Pinwheel Axis
-    Frozen
-    Chimera Boundary

- Green = viscous wall
- Aqua = bleed region

- Sample of journal file created
- created during an interactive
- session with GMAN

## Flow information is exchanged across zonal boundaries.
Connectivity defines how a zonal boundary is connected to other zonal boundaries.

- Flow information is exchanged across zonal boundaries.
- Connectivity defines how a zonal boundary is connected to other zonal boundaries.

- GMAN: Zonal Connectivity

- 1 & 3

- 2

- 4

- GMAN can automatically compute zonal connectivity for abutting (1 & 2).
- Overlapping (overset) grids use tri-linear interpolation to exchange information.
- Point-to-point match is best since direct transfer is possible and interpolation errors are minimized.

- Types of Zonal Connectivity
-    1)  Abutting, Point-to-point match
-    2)  Abutting, Non point-to-point match
-    3)  Overlapping, Point-to-point match
-    4)  Overlapping, Non point-to-point match

- Outer boundary

- Interior boundary

## GMAN: Overlapped Grids   

- Example of NLR Airfoil with flap
- Flap grid overlaps airfoil grid.
- Use flap grid to cut a hole in airfoil grid.
- Indicate edge points of cut are fringe points to interpolate boundary information from flap grid solution.
- Outer edge of flap grid is fringe boundary of flap grid and receives interpolated data from the airfoil grid.

- Fringe points

- Hole

- Fringe points

## WIND is not an acronym.
Solves several types of equations.
Contains variety of features and numerical methods.
Basic input files required are:
Input data file (*.dat)
Common grid file (*.cgd)
Common solution file (*.cfl) optional
WIND is executed using the WIND script with text prompts and responses.
WIND is run as a batch execution.
Simulation times to iterative convergence can range from minutes to days.

- Solves several types of equations.
- Contains variety of features and numerical methods.
- Basic input files required are:
- Input data file (*.dat)
- Common grid file (*.cgd)
- Common solution file (*.cfl) *optional*
- WIND is executed using the WIND script with text prompts and responses.
- WIND is run as a batch execution.
- Simulation times to iterative convergence can range from minutes to days.

- WIND

- Equation Sets in WIND:
-    Reynolds-Averaged Navier-Stokes (RANS)
-    Turbulence
-    Chemistry
-    Magneto-Fluid Dynamics (MFD)

- Features of WIND:
-    Cell-vertex, finite-volume formulation
-    Time-marching (steady or unsteady)
-    Space-marching for supersonic flows
-    Propulsion-specific boundary conditions
-    Multi-zone, structured grids
-    Abutting or overlapped zones
-    Parallel and multi-processor operation

## Input data file (.dat) is ASCII file.
File contains descriptive keywords.
“test” options used for special cases.
Online documentation lists all keywords.

- File contains descriptive keywords.
- “test” options used for special cases.
- Online documentation lists all keywords.

- WIND: Input Data File

## AXISYMMETRIC   Indicates flow domain is planar, axisymmetric.
BLEED   Specifies inputs for mass flow and porous bleed models.
FIXER   Turns on algorithm to fix bad points in flow (I.e. negative pressure).
IMPLICIT   Specifies algorithm to use for implicit time-marching.
MASS FLOW   Specifies inputs for outflow boundary condition.
RHS   Specifies algorithm to use for numerical flux.
SEQUENCE   Option to use coarser grid that is sequence of full grid.
SMOOTHING   Specifies algorithm for artificial dissipation.
THIN SHEAR LAYER   Option to use thin shear layer assumption.
TVD   Specifies algorithm for TVD limiting of flux terms.
WALL FUNCTION   Option to use a wall function for turbulence modeling.

- BLEED   Specifies inputs for mass flow and porous bleed models.
- FIXER   Turns on algorithm to fix bad points in flow (I.e. negative pressure).
- IMPLICIT   Specifies algorithm to use for implicit time-marching.
- MASS FLOW   Specifies inputs for outflow boundary condition.
- RHS   Specifies algorithm to use for numerical flux.
- SEQUENCE   Option to use coarser grid that is sequence of full grid.
- SMOOTHING   Specifies algorithm for artificial dissipation.
- THIN SHEAR LAYER   Option to use thin shear layer assumption.
- TVD   Specifies algorithm for TVD limiting of flux terms.
- WALL FUNCTION   Option to use a wall function for turbulence modeling.

- WIND: Select Keywords

- Some of the other most commonly used keywords include:

## ARBITRARY INFLOW   Proves inputs for the arbitrary inflow boundary condition
CHEMISTRY   Provides inputs for the chemistry model
LOADS   Provides inputs for summing forces on surfaces
ACTUATOR / SCREEN   Provides inputs for the actuator disk / screen model
VORTEX GENERATOR   Provides inputs for the vortex generator model

- CHEMISTRY   Provides inputs for the chemistry model
- LOADS   Provides inputs for summing forces on surfaces
- ACTUATOR / SCREEN   Provides inputs for the actuator disk / screen model
- VORTEX GENERATOR   Provides inputs for the vortex generator model

- WIND: Block Keywords

**arbitrary Inflow**
-    total
-    hold_totals
-    zone 1
-    uniform 0.6 14.0 460.0 0.0 0.0
**endinflow**

**loads**
-    print totals zones lift frequency 10
-    reference area 1.0
-    reference length 1.0
-    reference moment center 0.0 0.0 0.0
-    zone 1
-    subset I 33 337 j 1 1 k 1 1 force noslip
**endloads**

**chemistry**
-    fuel air ratio 1.0
-    file h2air-7sp-std-15k.chm
-    finite rate
-    mass fractions 0.993 0. 0.007 0. 0. 0. 0.
**endchemistry**

- Block keywords are input as a block of keywords that follow a certain format:

## Default initialization is uniform flow based on “freestream” values.
Initial flow solution can be from common solution file (*.cfl).
Arbitrary inflow can initialize a zone.
Boundary layer initialization on a wall (one j or k surface per zone).
Re-initialization of a “bad” zone.
Initialization of turbulence and chemistry values.

- Initial flow solution can be from common solution file (*.cfl).
- Arbitrary inflow can initialize a zone.
- Boundary layer initialization on a wall (one j or k surface per zone).
- Re-initialization of a “bad” zone.
- Initialization of turbulence and chemistry values.

- WIND: Flow Initialization

- WIND requires an initial flow field to start the marching
- schemes.  Some options for obtaining this include:

## Command-line script to run WIND.
Graphical interface also available (B4CFD).
WIND may be run interactively, via Unix at/batch commands, or via NQS system.
Executable need not reside on local system.
May run on a remote system.
Type  wind –help  to get list of options.

- Graphical interface also available (B4CFD).
- WIND may be run interactively, via Unix **at/batch** commands, or via NQS system.
- Executable need not reside on local system.
- May run on a remote system.
- Type  wind –help  to get list of options.

- WIND Script

## WIND: Parallel Operation

- WIND may be run in parallel on a multi-processor system, or on a cluster of heterogeneous systems.
- Fault-tolerant master-worker approach.
- Grid zones are distributed from the master to the worker systems for processing.
- PVM message passing is used on clusters; PVM or MPI may be used on multi-processor systems.
- WIND and PVM / MPI need not be pre-installed on worker systems.
- User specifies hosts via Multi-Processing Control (*.mpc) file.

- Multi-Processing Control (*.mpc) file:
- # loadlimit 1800
- host saturn nproc 12

## Version 5 released November 2002
Improved time history tracking
Improved CGNS compatibility
Vortex generator model
Direction specification at arbitrary inflow boundary
Improved smoothing algorithm
Chemistry improvements
OVERFLOW options
      -   Time step selection
      -   ARC3D 3-factor diagonal scheme
      -   Roe differencing
Koren and van Albada TVD limiters
Additional explicit operators

- Improved time history tracking
- Improved CGNS compatibility
- Vortex generator model
- Direction specification at arbitrary inflow boundary
- Improved smoothing algorithm
- Chemistry improvements
- OVERFLOW options
-       -   Time step selection
-       -   ARC3D 3-factor diagonal scheme
-       -   Roe differencing
- Koren and van Albada TVD limiters
- Additional explicit operators

- WIND: New in Version 5

## RESPLT: Residual Plotter.
Reads the List Output File (*.lis) and extracts residual and other iterative convergence information and creates an ASCII GENPLOT file (*.gen) for plotting by CFPOST.
Text-based program can be run interactively or in batch.
Reply to a few prompts depending on what information is to be extracted.
Asks for the name of the GENPLOT file to output.	

- Reads the List Output File (*.lis) and extracts residual and other iterative convergence information and creates an ASCII GENPLOT file (*.gen) for plotting by CFPOST.
- Text-based program can be run interactively or in batch.
- Reply to a few prompts depending on what information is to be extracted.
- Asks for the name of the GENPLOT file to output.

- RESPLT

- Sample of Selections:
-    2   L2 norm of residual of RANS equations per zone
-  23   L2 norm of residual of Spalart-Allmaras turbulence equation
-  17   Lift on surfaces as indicated by the LOADS keyword

- Red box indicate inputs to prompts

## RESPLT: CFPOST Plotting   

- Airfoil lift –vs- Cycles

- RANS L2 residual –vs- Iterations

- CFPOST can then plot the
- ASCII GENPLOT file.

## CFPOST: Common File Post-Processor.
Text-based program requires sequence of commands and can be run interactively or in batch.

- Text-based program requires sequence of commands and can be run interactively or in batch.

- CFPOST

- What does CFPOST do?
-   Plots GENPLOT files
-   Creates contour plots
-   Creates velocity vector plots
-   Outputs PLOT3D grid & solution files
-   Computes forces and moments
-   Integrates fluxes (mass, momentum, ...)
-   Averages flow over a cut or surface
-   Propulsion-specific analysis (rakes)

*3D flow visualization is better performed using *
*packages such as FAST, Fieldview, or Ensight.*

- Prompt waiting for commands

## CFPOST: Command Sequence   

- General sequence of CFPOST commands:
-   1) Specify grid file
-   2) Specify solution file
-   3) Specify units
-   4) Specify zone
-   5) Specify surface, cut, subset, etc...
-   6) Specify operation (plot, integrate, ...)
-   7) quit to exit

- To create PLOT3D files:
-   grid run.cgd
-   solution run.cfl
-   units fss
-   zone 1 to last
-      subset i all j all k all
-   plot3d x run.x q run.q unformatted mgrid
-   quit

- To plot a GENPLOT file:
-   plot data nsl2.gen
-   quit

- To create a report of forces on a wing:
-   grid run.cgd
-   solution run.cfl
-   units fss
-   zone 3
-      subset k all i all j 1
-   integrate force output forces.lis –
-      iviscous –
-      reference length 1.0 –
-      reference area 1.0 –
-      reference moment 0.0 0.0 0.0
-   quit

- To create a plot file of Cp distribution at a cut along a wing:
-   grid run.cgd
-   solution run.cfl
-   units fss
-   zone 2
-      subset i all j 1 k all
-   cut at z 0.25
-   variables x; Cp scale –1
-   genplot output cp.gen
-   quit

## Many options exist for using the programs that make up the NPARC Flow Simulation System.
The previous presentation discusses one approach:
 CFCNVT  GMAN  WIND  RESPLT  CFPOST
Online documentation provides further information.
Best way to learn is to see a demonstration and get some hands-on experience (next few hours).

- The previous presentation discusses one approach:
-  CFCNVT  GMAN  WIND  RESPLT  CFPOST
- Online documentation provides further information.
- Best way to learn is to see a demonstration and get some hands-on experience (next few hours).

- Summary of the System