
   FoilSimU II 1.5a beta

This is a beta 1.5a version of the FoilSim II 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 benson@grc.nasa.gov.

With this software you can investigate how an aircraft wing produces
lift by changing the values of different factors that affect lift.

There are several different versions of FoilSim II which
require different levels of experience with the package,
knowledge of aerodynamics, and computer technology.
This file is the manual for the university application version of the  program.
The file describes the various options available in the program.

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\FoilSimU
To launch the application, go to C:\ 
Assuming you have Java installed on your computer, type this command:

    java -cp (the PATH) Foil

for our example PATH, this would look like:

    java -cp My Programs\FoilSimU Foil

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 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.
  At any time, to return to the original default conditions,
  click the red "Reset" button at the upper right of the program.

  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 LAYOUT

The program screen is divided into four main parts:

   On the top left side of the screen is the View Window.
   The view window includes a graphic of the airfoil that you are
   designing and several buttons which control the graphic. 
   Details of the window are given in the Graphics section of this page.

   On the upper right side of the screen is the Control Panel.
   The control panel holds several choice buttons which
   control the analysis. You can select the type of analysis,
   the type of input and 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 computed lift or lift coefficient displayed.
   Details of the input and output variables are given below.

   On the lower right side of the screen is the Output Window.
   The output can be presented as graphs of airfoil performance,
   a probe which you can move through the flowfield, a lift meter, or printed
   numerical values of certain parameters.
   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 is the Input Window.
   Various input panels are displayed in this window.
   You select the input panel by using the choice
   button labeled "Input:" on the upper right panel.

GRAPHICS

   The View Window contains a schematic drawing of the wing that
   you are designing and some buttons to control the schematic drawing.
   Possible choices are colored blue while the selected option is colored yellow. 

      "Edge" shows the wing as viewed looking along the leading edge.
       The cross section appears as an airfoil or circle with the flow going
       going from left to right. 
       You can move the picture within the window by moving the cursor into 
       the window, holding down the left mouse button, and dragging the airfoil 
       to a new location. You can also "Zoom" in close to the airfoil by using 
       the green slider at the left of the window. If you get lost, pushing 
       the red "Find" button will return the airfoil to the initial position. 

       "Top" shows the wing as viewed from above looking down onto the
        planform. The flow is from bottom to top.
        Since FoilSim only solves for the two-dimensional 
        flow past objects, you won't see any flow in this view. It is provided 
        only to display the geometry of the wing area.

       "Side - 3D" shows an orthographic projection of the three 
        dimensional wing.

       "Moving" shows  particles flowing past the airfoil.
        The particles are drawn as line  "traces".
        The inclination of the trace is at the local flow angle, and 
        the left most part of the trace is the particle location. Particles 
        are being periodically released from a constant streamwise location 
        upstream of the airfoil.The streamwise distance between any two particles 
        is proportional to the local velocity. 

       "Frozen" is a snapshot of the moving particles.
        In this view, you can change the  streamwise release point of 
        the particles by moving the cursor into  the view window,
        holding down the left mouse, and dragging the particles 
        to the left or right. In this view, the particles are color coded by 
        the time at which they are released. (All of the yellow particles were 
        released at the same streamwise location at the same time.)

       "Streamlines" are collections of the particle traces to form a solid 
        flow line. 

       "Geometry" shows only the geometry of the wing or airfoil 
        with some descriptive labels but with no flow field.

OUTPUT VARIABLES 

  There are several different output options available for the Output Window 
  at the lower right. You select the type of output by using the red choice
  box on the control panel. 

        If you select "Plot", a graph will appear in the window. 
        The type of graph is described below.

        "Plot Selection" provides a panel in the output window which allows
         you to select the  type of plot.
         If you display a plot and begin to change the 
         input variables, it may become necessary to rescale the plot axes by 
         pushing the white "Rescale" button at the upper left of the window. 
         The types of available plots are listed below. 
 
           The default plot is the "Surface Pressure". 
           The yellow line will be a plot of the lower surface pressure,
           and the white line a plot of the upper surface pressure.
           For reference, the green line shows the value of free stream 
           pressure.

           You may also display the "Surface Velocity".
           As with the pressure, the yellow line will 
           be a plot of the lower surface, and the white line a plot of the upper 
           surface. If the "Stall Model" is used and the wing stalls, these 
           plots are not available.

           The remaining plot choices show "Lift" or "Lift Coefficient -Cl"
           versus each of the input variables.
           For these plots, the current value of the flow conditions is shown as 
           a red dot on the plot.

       The "Lift Meter" shows the current value of lift 
       (or lift coefficient) displayed in scientific notation.
       The meter is displayed in the output window and moves as the lift is varied.

       The "Probe" lets you explore the flow around the wing. 
       A probe control panel appears in the output window when you select "Probe"
       from the control panel. 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 located above 
       the gauge.

       The "Performance" option provides a written list of important  
       input and computed variables in the output window.
       You have two options for performance output;
       the "Data" option gives the computed lift and flow conditions, the
       "Geom" option shows the coordinates of the airfoil geometry and the
       local value of velocity and pressure. These numbers correspond to the
       plots of velocity and pressure described above.

  Some additional output from the program is displayed on the control panel 
  some input panels. 
  You can choose to display the lift or the lift 
  coefficient by using the choice box on the control panel. The value 
  is displayed in the output box to the right of the choice box. Lift 
  may be expressed in either English or metric units (pounds or Newtons). 
  On the Flight Test input panel is a group of output boxes that give the 
  atmospheric conditions of the air. The pressure, 
  temperature, and density will change depending on the altitude and planetary 
  inputs. On the Size input panel the geometric "aspect ratio" of the 
  wing is displayed. The aspect ratio is defined to be the square of the 
  span divided by the wing area 
  and is included here for later calculations of wing drag.

INPUT VARIABLES 

  The input variables are located on input panels that are displayed at the lower left.
  You can select the input to display by using the blue choice box on the control panel. 
  You can choose to vary the  Shape, the Size, or perform a Flight Test.

      If you choose to "Flight Test" (the default choice), you can
      change the value of lift by varying the speed, or the altitude.
      You can flight test your wing on the earth (default), on Mars, or in 
      the water by using the choice box at the upper right. You can also 
      choose to specify your own values of temperature and pressure for air, 
      or to specify your own fluid by providing a value of the fluid density.

      If you choose "Shape/Angle",  you can select a classic airfoil shape, 
      an ellipse, or a thin plate cross section by using the choice box.
      You can change the camber, thickness, or the angle of attack of 
      the cross section. You can also  
      choose to investigate the lift created by a rotating 
      cylinder, or a spinning ball. For these 
      problems you must specify the spin rate and radius. 

      If you choose "Size", you can vary the layout of the wing.
      You can change the chord, span, or the wing area.
      The ratio of the span to the chord is called the "Aspect Ratio"
      and this parameter also has an effect
      on the lift of the wing. If you have selected 
      a cylinder or ball shape, this input panel is not used. 

FoilSimU includes all of the options of the original
FoilSim plus some additional input and output panels.
These panels are made available so that you can study the details of the
conformal mapping used in the Kutta-Joukowski analysis.
In the analysis, flow around a cylinder is mapped into
flow around an airfoil. Using the input choice box
on the control panel, you can display a "Generating Plane" input panel.
The panel contains four input variables which
control the size and location of the generating cylinder
relative to the poles of the transformation, and the
strength of the point vortex which is embedded in the airfoil.
According to the "Kutta Condition" of the analysis,
the strength of the vortex is set to bring the aft stagnation point
to the trailing edge.
With this version of FoilSim, you can turn the Kutta condition
off by using the analysis choice box on the control panel to
study the effect.
A graph of the flow in the generating cylinder plane is
also available using the "Plot Selection" option of the
output choice box on the control panel.

SAVING RESULTS

  There is an additional output option for the application version of the program..
  The "Printed" option of the output choice generates an additional input panel.
  With this option, you can give a file name to record output data
  from the program and a short label for your own reference. Clicking on the
  "Open File" button returns you to analysis mode.
  To record data, you press the blue "Print Data" button on the
  control panel at the upper right of the program. When your FoilSimU session is
  finished, you can save the results by sending the specified output to your printer.


