XFOIL is an interactive program for the design and analysis of subsonic isolated airfoils. It consists of a collection of menu-driven routines which perform various useful functions such as:
- From MIT XFOIL Webpage -
XFOIL is primarily used in the drag buildup process to collect profile drag information for a specified airfoil under various flight conditions (Cdp column in the airfoil polar) as well as to model the stall condition for a wing section. Additionally, XFOIL can be used to define an optimal airfoil profile for a given set of initial conditions. This is extremely useful in developing experimental aircraft in the early stages of design.
A PDF version of this guide may be found here.
This is only a guide to obtain values for a specified airfoil and not a total user manual for XFOIL. For complete instructions go to the MIT XFOIL user manual. For the purposes of this guide, it is assumed that you are using Windows.
An extensive database of known aircraft airfoils can be found at the University of Illinois (UIUC) Incomplete Guide to Airfoil Usage.
A database of .dat and .gif files for airfoil profiles is at the UIUC Airfoil Coordinates Database.
? at any command line to see a list of available commands and their descriptions.
PANEwill set the number of panels to be sufficient for XFOIL. You may not see a change in the profile.
PPARwill show the new paneling if you changed the number with PANE. If not, you may begin with PPAR.
Nto change the number of nodes. Use the PANE number shown as a guide. More nodes have a higher resolution but run slower.
Enterkey until XFOIL is displayed.
Viscto toggle modes. OPERv should be displayed.
Mach. Similar to other commands this may be followed by an argument if you like. Enter the Mach number.
Alfa. This will show the results in the display. If a sequence of attack angle is needed, proceed to the next step.
Aseq. If you are performing a range of speeds, proceed to step 14.
Finishto open the data as a spreadsheet.