General Overview

• Introduction
• Command Syntax
• Processing Overview

Introduction

CFPOST is a post-processing tool for analyzing CFD results. It reads as input a Common Grid (.cgd) and Common Flow (.cfl) file, and may be used to perform many varied functions, such as listing and plotting results, generating reports, and producing files for other plotting packages and post-processors. Hardcopy plot output is available in Boeing intermediate plot file (IPF) or PostScript formats.

CFPOST provides commands for the user to precisely specify the information of interest (the variable command), the domain of interest (the zone, subset, surface, cut and rake commands), and the units of measure in which the results are to be presented (the units and variable commands).

Command Syntax

All CFPOST commands are of the form:

   command keyword [value] keyword [value] ...

In this guide all commands and keywords will appear in a fixed-pitch font and user specified values will appear in a slanted font. Commands and keywords can be abbreviated but such abbreviations should be limited to three characters. Words like and, at, and to cannot be abbreviated. Lists enclosed in "{" and "}" indicate that exactly one item from the list must be selected. Items enclosed in "[" and "]" indicate optional items. If a list is enclosed in "[" and "]" then only one of the list entries may be optionally selected.

Commands may be continued by terminating the line to be continued with a "-" (hyphen) and continuing on the next line. This may be repeated for as many lines as necessary. For example:

   integrate force -
      output force.lis -
      reference moment 100.0 0.0 10.3 -
      reference area 95.0

Comments may also be included. On any command, all characters following a "!" are ignored. For example:

   ! This is a standalone comment statement
   subset j all k all i 1   ! This is a trailing comment

Embedded tabs and blanks are ignored as are completely blank lines.

For the most part CFPOST is case insensitive, i.e., upper and lower case characters may be freely intermixed. There are two exceptions however. Filenames must be entered in the correct case on systems where filenames are case sensitive (i.e., Unix). Note that if a suffix (.lis, .com, etc.) is not provided on a filename, CFPOST will automatically provide one and it will be lower case. Thus, if a file has an upper case suffix it must be specified explicitly. The second exception where case is important is variable names on the variable command.

Processing Overview

A CFPOST session is generally divided into a well-ordered sequence of commands as follows:

• grid and solution commands to define the input files to be processed.
• A units command to define the default system of output units.
• zone, subset, cut, and rake commands to define the domain of the input files to be processed.
• A variable command to define the information requested.
• A processing command to generate the requested information.

The commands that comprise the above sequence will be more fully described in the following sections.