Running RPA

Graphical User Interface

You start RPA either by clicking on an icon (on Desctop or in file browser), or typing RPA.exe on a command line.

Although command line arguments are not required when starting RPA, the available arguments are shown below:

Option	Value	Description
-t or --thermo	FILE	Thermodynamics database. Default is resources/thermo.inp
-ut or --usr_thermo	FILE	User-defined thermodynamics database. Default is resources/usr_thermo.inp
-p or --properties	FILE	Properties database. Default is resources/properties.inp
-up or --usr_properties	FILE	User-defined properties database. Default is resources/properties.inp
-i or --input	FILE	Problem configuration file that has to be loaded. Default is last opened file.

Command line arguments must be in the command line that you use to start RPA.

See chapter Thermodynamic Database Editor for more information about database types.

After starting the program, the RPA main window will appear. The main windows features menu bar, toolbar and working area, that can be used in two views: Express Analysis and Extended Analysis.

Express Analysis view is intended to keep the subset of input parameters and results on the same screen, and can be useful for quick analysis of the rocket engines, when theoretical performance is the only result that should be considered.

Express Analysis view

Extended Analysis view consists of several screens which conveniently group the input parameters and results. The desired screen can be activated by mouse click on corresponding button on the list at the left side of the main window. You can enlarge or narrow the list while the screens will be narrowed or enlarged, dragging the vertical bar between the list and the screens right or left.

Extended Analysis view (Lite Edition)

Extended Analysis view (Standard Edition)

In RPA Standard Edition, there are 4 different lists grouped in the following folders:

• Initial Data containing items Engine Definition, Propellant Specification, and Nozzle Flow Model,
Performance Analysis containing items Chamber Performance, Nested Analysis, and Propellant Analysis,
• Engine Design containing the item Chamber Geometry,
• and Tools containing the item Thermodynamic Database.

Command-line utility

You start command-line utility by typing rpac.exe on a command line.

The available command-line arguments are shown below:

Option	Value	Description
-t or --thermo	FILE	Thermodynamics database. Default is resources/thermo.inp
-ut or --usr_thermo	FILE	User-defined thermodynamics database. Default is resources/usr_thermo.inp
-p or --properties	FILE	Properties database. Default is resources/properties.inp
-up or --usr_properties	FILE	User-defined properties database. Default is resources/properties.inp
-i or --input	FILE	Problem configuration file that has to be loaded. Default is last opened file.
-o or --output	FILE_NAME_PREFIX	Output file name prefix without extension. Default is "info".
-opt or --optimize		find optimum propellant mixture ratio, bypassing the one defined in input configuration file.
-bau or --bau_units		print out results using britisj-american units.

Upon completion, the command-line utility prints out the results in console window and writes it into the log file.

Scripting utility

Only available in RPA Standard Edition

Scripting utility is a tool that can be used to execute user's own problems.

Scripting utility can be started in either an interactive mode or a batch mode.

You start scripting utility by typing rpas.exe on a command line. The available command-line arguments are shown below:

The available command-line arguments are shown below:

Option	Value	Description
-t or --thermo	FILE	Thermodynamics database. Default is resources/thermo.inp
-ut or --usr_thermo	FILE	User-defined thermodynamics database. Default is resources/usr_thermo.inp
-p or --properties	FILE	Properties database. Default is resources/properties.inp
-up or --usr_properties	FILE	User-defined properties database. Default is resources/properties.inp
-i or --input	FILE	Script file.
-o or --output	FILE_NAME_PREFIX	Output file name prefix without extension. Default is "info".

Upon start up, scripting utility prints out the prompt rpa>, inviting you to type any valid command.

Type "exit" to stop the interactive interpreter. See Scripting Built-In Commands and Scripting API Reference to get more information about available commands.

To start scripting utility in the batch mode, specify the name of the script you want to execute as a command-line argument:

rpa.exe -i some_script.js

After completion, the scripting utility prints out the results in console window and writes it into the log file.

Last modified: May 14, 2011