Parametric Speed and Power
“How fast will it go?” The Orca3D Parametric Speed/Power Analysis module has two different prediction methods: the Savitsky method to predict the speed/power curve for chine hulls, and the Holtrop method to predict the speed/power for displacement hulls.
Most of the required input parameters are automatically computed from your model, although the user can input or override the values. Results are quickly generated and professionally formatted, and include checks to ensure the validity of the results. Any parameters that are outside of the ranges of the prediction method are flagged.
The results of the analysis are presented in easy-to-read reports, which include a summary of input data, checks of the parameters of your design versus the limits of the analysis method, and performance data versus speed. Plots of various parameters are also included, and the entire report may be printed or exported to Microsoft Excel or PDF.
Orca3D provides a few industry-standard methods for parametric resistance prediction, as well as a full computational fluid dynamics (CFD) capability. To complement these, Orca3D includes an interface to HydroComp’s NavCad software, used for hydrodynamic and propulsion system simulation for vessels of any size. The flotation condition, speed(s), density and viscosity of the water, mono- or multi-hull, and the hull geometry are all exported via a NavCad script. NavCad can be launched directly from Orca3D with this script, saving time and eliminating transcription errors.
NavCad builds on Orca3D resistance capabilities with a number of different parametric methods, and allows the user to do a complete powering analysis with propeller and engine characteristics. This powering analysis can use one of NavCad’s parametric methods to develop the underlying resistance curve or, for even more accuracy, the resistance data can come from Orca3D Marine CFD. Together, Orca3D, NavCad, and Orca3D Marine CFD provide the naval architect with a complete speed and power performance prediction toolset for almost any size and type of hull.
You can also evaluate the results with their suite of performance, weight, stability and other tools. I have found that even outside of boat design they have provided many new and useful controls that add to Rhino’s overall functionality on all kind of projects. Beyond the tools themselves the developers at Orca3d have always offered great support whether it’s understanding the program itself or helping you to figure out the best way to perform a necessary task. And that is probably the bottom line. Orca3d is software designed for Naval Architects and yacht designers by a group of practicing Naval Architects. They understand not just how to write software code, but what tasks need to be done and how a design professional will likely want to do them. Often that kind of experience and sensibility is a rare thing.