A further module in
the workflow would be the simulation of the rig. This
work is in progress. Classical
wing theory can be used to calculate the forces acting on the sails.
The theory relies on the input of the aerodynamic characteristics of
the 2D sail sections. The program XFOIL was used to create a database
of discrete values of the required coefficients. The theoretical
background is described in this report.
Sail2D is a program that
interpolates in the database and provides the coefficients for sections with optimimum camber at arbitrary
independent variables. In the version 2.2 linear interpolation is
replaced by spline interpolation, a bug is fixed and the range of
allowed mast diameters is extended to D/c
= 50%. In version 2.3 a module is added that also calculates the
coefficients for saill sections with a fixed and predescribed camber.
Details of the program are
explained in the user's manual that can be downloaded here:
Sail2D User's manual:
A zipped file with the
program Sail2D can be downloaded here
(click on picture)