If you see only a grey box at the top of this page, be sure that Java is
enabled in your browser. If Java is enabled, and you are using the Windows XP
operating system, you need to get a newer version of Java. Go to this link:
try the "Download It Now" button, and then select "Yes" when the download box from Sun
If you experience difficulties when using the sliders to change variables,
simply click away from the slider and then back to it.
the arrows on the end of the sliders disappear, click in the areas
where the left and right arrow images should appear, and they
- On the
top left side of the screen is a graphic of the engine you are
designing or testing. In the Design Mode, the drawing is a schematic,
while in Tunnel Test Mode the drawing is an animation.
- 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 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 as photos
of the engine parts with descriptions of their purpose. 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.
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.
variables for each engine component can also be varied.
The components and 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. If you change the Output Display to "Pictures"
you can view an actual photograph and description of each 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.
Mode, Units, Output Display
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
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; you are comparing one engine against another engine.
In Tunnel Test Mode, you are only working with one engine.
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 performance 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
of the engine model which you specified in Design Mode.
You can use any of the output panels to see how the various engine parameters
change with speed, altitude, or throttle setting.
You can load models
of real turbine engines for comparison with your design.
can always reload your design to continue testing. In Design Mode,
you can use the existing engine models as good starting points for
calculations can be performed in either Metric or English units.
You can always return to the default conditions by pushing the red Reset
button at the upper right.
The program will calculate an average 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 type and design of the engine, the size
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 Graphical Output display.
You can find which component is exceeding the temperature limits by
selecting "Component Performance" on the Output display and looking
for the red temperature 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.)
red Output menu allows you to change the contents of the
output window on the lower right side of the screen. You can choose
to display output boxes with numerical values of the engine
and component performance,
as described below. Or you can display photographs and descriptions
of each engine part. Or you can display graphs of the variation of the value
of pressure and temperature at various stations
through the engine. You can also display a T-s Plot or a P-v
Plot, which are used by engineers to determine engine performance.
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.
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
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),
compressor pressure ratio (CPR) ,
engine thermal efficiency,
nozzle exit velocity (V exit), free stream dynamic
pressure (q0), and specific impulse (ISP) are displayed.
Nozzle exit pressure (Pexit) and fan nozzle exit pressure (P fan exit)
and the compressor face Mach number (M2) are also displayed.
The Component Performance output panel shows the variation of
total pressure and temperature through the engine.
Learning Technologies Project will continue to improve and update
EngineSim based on user input. Changes from previous versions of
the program include:
- On 18 Oct
12 version 1.7b was released. This version has been updated
to include the compressor pressure ratio on the output panel.
This will help users to see the difference between Design Mode and
Tunnel Test Mode.
- On 26 Oct
05 version 1.7a was released. This version has been re-sized
to fit the NASA portal. Some additional output variables have
been added and a correction to the gross thrust calculation was
made. The logic for moving the engine graphic was also changed.
- On 20 Feb
04 version 1.6e was released. This version has a cleaner look
by moving the units into the output boxes. Engine thermal
efficiency is now output instead of compressor face Mach number.
- On 11 Dec
03 version 1.6d was released. This version has separate input
panels for the ramjet burner and nozzle and allows the user
to specify the ramjet fuel.
- On 25 Nov
03 version 1.6c was released. This version lets the user move
the engine graphic. The user can also specify any fuel by giving
the fuel heating value. A bug related to the nozzle total temperature
has been fixed.
- On 17 Oct
03 version 1.6b was released. This version has a slightly
modified graphics window for resizing the application.
Tabs are also added to the printed output of the application.
- On 15 Sep
03 version 1.6a was released. This version includes the component
output panel, additional input and output variables,
and some new input options for the flight conditions.
This is the first version which is available as a Java application.
The application permits the user to save results between sessions
and is run off-line.
There are minor changes to the layout of the program
and bugs in the weight calculations are corrected.
- On 6 Jun
03 version 1.5h was released. This version corrects a bug
in the loading of existing engine models. Materials information is
now included in the upload.
- On 29 Apr
03 version 1.5g was released. This version corrects a bug
in the ramjet temperature calculations.
- On 18 Mar
03 version 1.5f was released. This version includes a correction
to the weight calculation when you change compressor face area.
- On 17 Sep
01 a special version for undergraduates was released. This version includes
the ability to reset most of the limits in the program.
- On 22 Aug
01 version 1.5b was released. This version includes more corrections
to the ramjet analysis and some slight changes to the variable limits.
A "sleek" version of the program is now available for experienced users.
- On 19 Apr
01 version 1.5 was released. This version includes improved graphics
and a more consistent input environment. There are also corrections
to the ramjet analysis from previous versions.
- On 13 Oct
00 version 1.4 was released. This version includes material properties
for each component and a calculation of the engine weight. Temperature
limits for each component are also checked.
On 26 Sept
00 version 1.3 was released. This version uses the "card format"
for input and output. Component input panels are invoked from
the engine graphic. Optional photos of the components are included
on the output panel.
On 31 Mar
00 version 1.2 was released. This version includes a ramjet
On 2 Dec
99 version 1.1 was released. This version includes a variety
of plots and an optional animation displays. This applet enables
the student to interactively observe the effects of engine component
performance on thrust and fuel consumption.
the following conditions in EngineSim:
Airspeed should be 0, the Altitude 0, and the Throttle 100. Record
(F net) ___________and the Fuel Flow __________.
Now go ahead and change the altitude to 10,000 ft. and the Airspeed
to 350. Did the thrust increase or decrease? Did the fuel flow increase
or decrease? Thrust ________ Fuel Flow__.
What happens when you choose a different engine? Choose a jet with
afterburner and record the thrust ___________ and the fuel flow
Choose a turbofan engine and record the thrust _____________ and
the fuel flow________.
What can you conclude about the effect of an increase in altitude
and airspeed on thrust? __________________________________ On fuel
Which engine is most fuel efficient? _______________________________
EngineSim - Engine Simulator:
Parts of a Jet Engine:
Calculating Fuel Flow Rate:
- Credits for EngineSim
- Beginner's Guide to Propulsion
- Beginner's Guide to Aerodynamics
- Beginner's Guide to Aeronautics