Program UliSpeed
The logical next step is
the combination of UliTank and UliSail to create a velocity prediction
program (VPP) that determines the equilibrium of forces and moments for 5 degrees of freedom (DOF).
There are
significant
differences between UliSpeed and classical VPPs. UliSpeed is based on
numerical modeling instead of using empirical coefficients. The
theoretical background and a comparison with measurements on the
water are described in this report.
UliSpeed allows,
like UliSail, the optimization of the trim parameters of the sails.
There is a difference, because UliSpeed maximizes the boat speed,
whereas UliSail maximizes the driving force. The optimal trim might therefore be different.
If you want to use UliSpeed, you have to have a table of offsets of
your boat. If this is not available, you can still use UliSail. An additional feature in UliSpeed is the
computation of the added resistance in waves. The 6th DOF, the
resulting yaw-moment, is calculated at the end of the optimization and
the rudder angle that will balance the yacht is proposed. The
program writes several files on output with the detailed description of
the sails, the forces and moments, the boat speed, the leeway, the heel
angle and many more helpful results. Additional
scripting files are written that enable you to easily create
3D-surfaces of the flying shapes of the sails with your CAD-program.
The latest version can also predict the speed of model yachts. Please
use only the latest update 2.11, since it also contains further
improvements and bug-fixes.
Details of the program are explained in the user's manual that can be downloaded here:
UliSpeed User's manual:
A zipped file with the
executable
program UliSpeed_2.11 can be downloaded here
(click on picture)
(click on picture)If you need an IGES-file of your sails, created with UliSpeed, you can send an e-mail to: ulrich(at)remmlinger.com
A good place to discuss UliSpeed is this: forum.