MANUAL

           EngineSimU  Application



This is the beta 1.8a version of the NASA Glenn EngineSimU application
program, and you are invited to participate in the beta testing. If
you find any errors in the program or would like to suggest
improvements, please send an e-mail to benson@grc.nasa.gov.

With this software you can investigate how a turbine (or jet) engine produces
thrust by changing the values of different engine parameters.

RUNNING THE APPLICATION

This program is a Java application and you must have Java installed on your computer
to operate the program. An application works differently than a Java applet
available on the Internet. This program runs "stand-alone" and can read and write
files to your computer. To launch the program, you need to know the PATH to the
folder where the program has been extracted. The PATH will be something like
C:\My Programs\EngineSimU
To launch the application, go to C:\      
Assuming you have Java installed on your computer, type this command:

    java -cp (the PATH) Turbo

for our example PATH, this would look like:

    java -cp My Programs\EngineSimU Turbo

GENERAL INSTRUCTIONS

This program is designed to be interactive, so you have to work with the program.
There are a variety of choices which you must make regarding the analysis and the display
of results by using a choice box.
A choice box has a descriptive word displayed and an arrow at the right of the
box. To make a choice, click on the arrow, hold down and drag to
make your selection.
The current values of the design variables are presented to you in boxes. By convention, a white box with
black numbers is an input box and you can change the value of the number. A black box with
yellow or red numbers is an output box and the value is computed by the program.
To change the value in an input box, select the box by moving the cursor into the box
and clicking the mouse, then backspace over the old number, enter a new number,
then hit the "Enter" key on your keyboard. 

You must hit Enter to send the new value to the program.

For most input variables you can also use a slider located next to the input box.
Click on the slider bar, hold down and drag the slider bar to change values, or
you can click on the arrows at either end of the slider.
If you experience difficulties when using the sliders to change variables,
simply click away from the slider and then back to it. If
the arrows on the end of the sliders disappear, click in the areas
where the left and right arrow images should appear, and they should reappear.

SCREEN

The program screen is divided into four main parts:

   On the top left side of the screen is a graphic of the engine you are designing or testing. 
   You can move the schematic by using your mouse and you can select
   input panels by clicking on the words above the schematic.

   On the upper right side of the screen are choice buttons which
   control the analysis. You can select the type of analysis,
   the type of output to be displayed, and the units to be used in the calculations.
   You will find a yellow "Reset" button which returns the program to its
   initial state, and a red "Exit" button to kill the application.
   You will always see the overall engine performance displayed as thrust, fuel flow, airflow,
   and computed engine weight.

   On the lower right side of the screen are the results of engine performance
   calculations. The output can be presented as numerical values
   of certain parameters, graphs of engine performance, or of
   the individual components. You
   select the type of output displayed by using the choice
   button labeled "Output:" on the upper right panel. 

   On the lower left side of the screen various input panels are displayed.
   You can select the input panel by clicking on the name or the
   component in the graphic at the upper left.
   Limits are established for the variables in the program. If you
   click on "Limits" on the schematic, you will invoke a special
   input panel that allows you to reset those limits.
   You must push the blue "Submit" button to send your changes
   to the program.

ENGINE DESIGN: 

   You can choose from four different types of engines: a simple 
   turbojet, a jet with afterburner,  a turbofan engine, or a ramjet.

   Selections are made on the graphics window by clicking on the engine name. The chosen
   engine is shown in yellow.

   Flight Conditions include the Mach number, airspeed, altitude, pressure,
   temperature, and throttle and afterburner settings. There are several different
   combinations of these variables available for input using the choice button
   on the input panel. The pressure and temperature are computed as functions
   of the altitude by using a Standard Day atmospheric model.

   Design variables for each engine component can also be varied.
   The variables include the Inlet (pressure recovery), Fan (pressure
   ratio, efficiency, and bypass ratio), Compressor (CPR, compressor
   efficiency), Burner (fuel,maximum temperature, efficiency, pressure ratio),
   Turbine (turbine efficiency) and Nozzle (maximum temperature, efficiency,
   A8/A2). As you choose a different component the part of the engine
   being affected is highlighted in the graphic by changing from its
   default color to yellow. 

   Engine Size can be specified by either the frontal area or the diameter.
   As the engine size changes, the grid background changes in
   proportion to the size. The distance between any
   two grid lines is 1 foot.

CHOICES: 
   Mode, Units, Output Display

   The program works in two modes: Design or Tunnel Test Mode. 

   In the Design Mode,
   you can change design variables including the flight conditions,
   the engine size, the inlet performance,
   the turbo machinery compressor and turbine
   performance, the combustors or burner
   performance, or the nozzle performance.
   For a turbofan engine design you can
   also vary the fan performance and the bypass ratio.
   In Design Mode, any change in an input parameter produces a new engine
   design. You have to be very careful when drawing conclusions about
   the effects of input variables on performance because you are not comparing the effects
   on the same engine.

   In Tunnel Test Mode
   you can vary only the flight conditions and you can not change
   any of the component design parameters except the throttle setting.
   The values of some of the parameters like inlet recovery and nozzle area
   may change according to choices that you made during design.
   In Tunnel Test Mode you are evaluating the off-design performance
   of the engine model which you specified in Design Mode.
   In Tunnel Test mode, you can load models
   of existing turbine engines for comparison with your design. You
   can always reload your design to continue testing. In Design Mode,
   you can use the existing engine models as good starting points for
   your design.

   The calculations can be performed in either metric or English units.  

MATERIALS INPUT

   The program will estimate the weight of the engine that 
   you design. The thrust to weight ratio of the engine 
   is displayed in the numerical output and is a measure of the efficiency of 
   the engine. The weight depends on the number of stages in the compressor and 
   turbine, the diameter (frontal area) of the engine, and the component materials. 
   The program begins with standard materials for the components, but you can 
   change the materials and see the effects on weight of the engine. Just push 
   the blue Materials choice button on any component input panel. You 
   can also select to define your own material by choosing My Material from the 
   menu. Just type in your own values for material density and temperature limit. 
   The program will check the temperature throughout the engine design against 
   the material limits. If you exceed a limit, a flashing warning will occur 
   in the schematic. You can see the temperature limits by choosing Temp Variation 
   in the Output Display. (For the afterburner and the ramjet, the graphical 
   temperature limits are based on the flow temperature, not on the material 
   temperature, and are slightly higher than the material limits. Cooling airflow 
   is often used along the walls of these components to keep the material temperature 
   within limits.)

GRAPHICAL OUTPUT

  The red Output Display menu allows you to change the contents of the output window in the 
  lower right side of the screen. You can choose to display output boxes with 
  numerical values of the engine performance, as described below. You can display 
  the variation of the value of pressure and temperature at various stations 
  through the engine. Or you can also display a T-s Plot or a P-v Plot, which 
  are used by engineers to determine engine performance.

  To generate your own performance plots, select "Generate" from the graphics window. The input 
  panel will now display some additional buttons and sliders to generate a plot. 
  Choose the variables to be plotted using the pulldown menus and then push 
  the "Begin" data button. Set the value of the independent variable by using 
  the slider or the type-in box. Push the blue "Take Data" button and a data 
  point will appear on the graph. Set a new value for the variable and take 
  another data point (up to 25 points in any order). When you are finished, 
  push the "End" button and a line will be drawn through your data points. To 
  start a new graph, push "Begin" and your old graph will vanish.
  When you are finished, push the red "Exit" button and you will return
  to free stream conditions.

NUMERICAL OUTPUT

  Numerical Output from the program is displayed on three performance panels.
  The total engine performance is always displayed on the control panel
  panel at the upper right and includes the engine net thrust,
  the fuel flow rate, the engine air flow rate,
  the engine weight, the thrust to weight ratio, and the
  specific fuel consumption.
  An additional Engine Performance output panel shows the
  fuel-to-air ratio, the engine pressure ratio (EPR)and engine temperature ratio (ETR),
  gross thrust, and ram drag. Additional component performance
  parameters, such as the nozzle pressure ratio (NPR), engine thermal efficiency,
  nozzle exit velocity (V exit), free stream dynamic
  pressure (q0), and specific impulse (ISP) are also displayed.
  The Component Performance output panel shows the variation of
  total pressure and temperature through the engine.
 
SAVING RESULTS

  There are two additional input panels which are invoked from the schematic drawing.

  The "Save" option allows you to provide the program
  with a file name and then to click on a button which saves all of the inputs
  necessary to run the program. When you begin another EngineSimU session,
  you load this information back into the program by invoking the "Save"
  option, providing the name of the saved file, and then clicking the "Retrieve"
  data button. The program is then in exactly the same state as it was when you wrote
  the save file. 

  The other input panel is the "Print" option. When this option is
  invoked from the schematic, you can give a file name to record output data
  from the program. The format for the output is selected by several buttons on
  the Print input panel. To record data, you press the blue "Print Data" button on the
  control panel at the upper right of the program. When your EngineSimU session is
  finished, you can save the results by sending the specified  output to your printer.