is a beta 1.0a version of the TunnelSys Tunnel Test Applet program, and you are invited
to participate in the beta testing. If you find errors in the program or
would like to suggest improvements, please send an e-mail to Thomas.J.Benson@nasa.gov.
TunnelSys - Tunnel Test Applet
With this software
you can investigate the process of wind tunnel testing
by changing the conditions of a test of a representative wing model.
You can look at surface pressure distributions, probe the flow field, and
use several flow visualization techniques.
is a series of three Java applications which students can use to
explore the process of
wind tunel testing.
In wind tunnel testing, an engineer must first design and build a wind tunnel
with all of the appropriate instrumentation included.
The model is then placed in the tunnel
and air is blown over the model.
Different diagnostic techniques may be employed during a
wind tunnel test.
The instrumentation records the desired information for the model designer.
The engineer who conducts the wind tunnel test is
not normally the same person who designed the model, but someone who is a specialist
at wind tunnel operation.
The data from the test normally goes to a third engineer who performs the necessary
data reduction and produces performance plots for the initial engineer.
To demonstrate the process used to conduct wind tunnel testing, we have produced an
applet version of TunnelSys.
Because of security limitations with Java, you can not save designs or results produced
with the applet version. The full application version does permit a team of students
to work on the various systems engineering aspects of wind tunnel testing.
The applet at the top of this page is the Tunnel Test portion of the TunnelSys applet
and application. It is presented here so that students can gain familiarity with
the testing part of the process.
This version of the Tunnel Test applet includes an on-line user's manual which describes the
various options available in the program and includes hyperlinks to
pages in the
Beginner's Guide to Wind Tunnels
describing the math and science of wind tunnels.
More experienced users can select a
version of the program which does not include
these instructions and loads faster on your computer.
You can download these versions of the program to your computer
by clicking on this yellow button:
With the downloaded version, you can run the program off-line and do not
have to be connected to the Internet.
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 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 green 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 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 pops up.
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
program screen is divided into five main parts:
top left side of the screen is the View Window.
The view window includes a graphic of a wing model in a wind tunnel.
During the test, the view in the tunnnel will change depending on your
inputs. You can view either a solid model or a transparent model by selecting
the buttons below the graphics. The yellow-lighted button is your selection.
top right side of the screen is the Diagnostics Window for your model.
You can choose to display either the surface pressure or velocity by selecting the
button below the window. There are three lines plotted on the screen; the yellow line
is the surface distribution of the flow variable on the lower surface of the model,
the magenta line is the distribution on the upper surface, and the green line is
the reference value for the free stream conditions.
lower left side of the screen is the Input Panel.
Details of the variables
are given below. There are also some selection buttons for Flow Visualization.
You can choose to display smoke traces, particle traces, or no trace in the view
window by clicking on the appropriate button. Calculations can be performed in either
Imperial or Metric units by using the choice button.
middle right side of the screen is the Probe Panel.
Details of the probe operation
are given below.
lower right side of the screen is the Output Panel.
Details of the output variables
are given below.
The Probe Panel contains a computer drawing of an output gauge
and some buttons to the left. By default, the probe is
turned off. You turn the probe on by pushing one of the white buttons
on the Probe Panel. The probe itself will then appear in the View Window. You
change the location of the probe using the sliders to the left and below
the gauge on the Probe Panel. The value of the pressure or the velocity at the location
of the probe tip (magenta ball on the view window) is displayed on the
gauge. Or a green trail of "smoke" is swept downstream from the probe
location. You turn the probe off by using the red button.
The input variables
are located on the panel that is displayed at the lower left below the View Window.
There are three input variables;
the speed of the flow,
the angle of attack of the model,
the tunnel static pressure.
As you vary any of the input variables, the resulting orientation is shown in the
View Window, the values of the surface variable are shown in the Diagnostic Window,
and the computed lift is shown on the Output Panel.
By default, the program begins with no flow through the tunnel. Notice that for this version
of TunnelSys you can not change the shape of the wing being tested. In the
full system version
you can put different wing designs in the tunnel.
The output variables
are located on the panel that is displayed at the lower right below the Probe Panel.
The chief output from the program is the computed
the lift of the wing.
The lift depends on the tunnel conditions so the
total pressure in the tunnel are also displayed.
For the full system version, as you load different wing designs, the output panel
gives a description of the
The Education Programs
Office will continue to improve and update TunnelSys based on user input.
Changes from previous versions of the program include:
On 5 Aug 09,
version 1.0a was released. This is the first released version
of the program.