WinDesign VPP

WinDesign is a velocity prediction program (VPP) used by naval architects,  yacht designers,  aerodynamicists and hydrodynamicists, experimentalists, handicappers, rule-makers,  researchers and students for over 20 years.

In those 20 years, yacht design has advanced in many areas. Now most designers produce 3D hull and appendage surfaces.  Computational fluid dynamics is now used by many designers to predict forces and flow for the boats, rigs and sails.  These and many other changes have been enabled by the increasing number of highly-skilled and technically proficient naval architects graduating from universities or technical institutes.

These developments and others have made it possible for the latest version of WinDesign VPP to help you in a number of ways:

Importing your geometry

Because we now typically represent our hull surfaces as NURBS, WinDesign imports your hull surface directly and then make offsets from the surface. 

Processing of your lines

Because we have the surface, we have the information to make offsets, float the boat to your specifications, deal with measurement and sailing weights, and more. This means you don’t have to have to make offsets in some external program, pre-process them with the LPP, make flotations, and export to the VPP.  All those extra steps are gone.

Build your model with components.  A hull is a component, a keel is a component, a sail is a component, and so on.  You import or make these using surface generators in WinDesign, and then assemble your boat.  Each component is a surface allowing for many additional services, such as meshing, intersections, visualisation, etc.

Twin rudders, canting keels, daggerboards, and more

The component approach lets you model the most complicated systems… even adding an arbitrarily-oriented hydrofoil.  And the shifting weight from the canting fin and bulb are linked to the fin and bulb components in the weight sheet helping streamline a typically time- consuming process.

Added solution methods for determining rudder angles and vertical forces

The latest version of WinDesign can balance more forces and moments, determining what rudder angles are required for yaw balance, what vertical forces are generated from canted appendages, and more. 

New methods to bring in CFD Data

The availability of hydro and aero CFD data has offered new opportunities for performance prediction and some novel and advanced methods have been developed to help you take advantage of this. 

New Aero CFD import

For example, one often has aero data where yaw sweeps were done with different sail trims, twists, positions and so on.  One of the new methods in WinDesign can bring this data in and work with it directly rather than going through a smoothing process to create lift and drag coefficients.

New component-based force modeling

There is the option to create custom force models for different types of components.  For example, you may want to look at several different formulations to calculate viscous drag on your daggerboard.  Or perhaps write a new wave resistance formulation that is encapsulated in a Dynamic Link Library.

Visual view

A 3D graphical representation is shown for each Opset  to help verify that all the components are in the correct position, and look right visually.  You can essentially “change the channel” to view each Opset. An Opset is a combination of the flying sails and the underwater configuration.

Comparative analysis

One of the key features of WinDesign has always been the ability to easily compare the performance of two or more yachts.  One yacht is a trialhorse against which the others are compared.  Now this can be done on an Opset-by-Opset basis along with graphing of these deltas.

Detailed results output for each component

After a run you can look at items such as flow angles, viscous drag, lift coefficient, location of centre of pressure, and more for a component such as the port twin rudder, or the keel, and so on.  Some of these appendages may be emerging with heel, so there are routines to determine how much if any of the component is in the water - wetted areas and centres.

Flotation-specific component setup

You may want three flotations conditions that vary the angle of attack or dihedral on a foil, such as a daggerboard.  This can be done by changing these parameters independently in each flotation.  The program will run these, and you can see what the optimum angle might be as a function of wind speed and angle.

Monohulls, multihulls, model yachts, dinghies, J-class and more

WinDesign is offered in several versions that treat multihulls separately from monohulls.  The solution methods are different for multihulls and dinghies. WinDesign v1 (1990) is thought to have been the first useful and publicly-available VPP for multihulls.  Various class specific modeling has been developed as well, such as the J-Class formulations.