Author: Josip Basic

Check out the new version of the Rhino automatic shell mesher for FEA here

Since we are now leaving the testing stage, we offer our solvers free to all public, without the requirement to register and log-in.

Have fun, and enjoy the Prelimina tools!

We're working on extending the solver to obtain results of the pressure and wave fields. This means soon you will be able to:

• inspect and optimize the pressure distribution along the hull,
• obtain accurate wake fraction distribution,
• obtain thrust deduction factors,
• optimize fore and stern wave generation systems,
• etc.

On the featured image, you can see the solution using original Michell's theory vs. the corrected viscous solution, obtained within milliseconds. The hull is the standard KCS test, which can be easily validated.

We'll keep you updated!

We've added the KCA series to the open-water solver. It includes the cavitation effects on the thrust and torque. A polynomial formulation is used for estimation of the relevant coefficients according to the following reference:

Radojcic, D. An engineering approach to predicting the hydrodynamic performance of planing craft using computer techniques. Transactions of the Royal Institution of Naval Architects, Vol. 133, 1991, pp. 251–267.

A paper about the novel method has been published in a Q1 journal, Ocean Engineering. You can read the full text here. The paper went under a rigorous peer review, through which we have enhanced the method even more. Their feedback is greatly appreciated! The next step is to publish a validation study on our trim and sinkage solver.

Dear all, thank you for your patience. We are happy to say that we have improved the solver. The resistance solver now converges better and yields more accurate trim and sinkage results.

Moreover, the Rhino plug-in is coming for Chrismas!

This is a major update that includes:

• Trim and sinkage solver
• Transom effect on a) wave-making b) viscous pressure resistance

The trim and sinkage solver separately assumes the pressure distribution from wave-making and local flow. At the moment, local flow is approximated based on this, which is crude, but still okay for an approximate guess for (semi-)displacement ships. The method that includes transom effects on wave-making is a novelty, more info soon.

This is a development version, please keep that in mind, and expect more updates soon! At the moment there are > 80 active users that occasionally do calculations. Thanks to those that gave me feedback!

If one looks at e.g. the Wide-light validation example, the trendline of trim and sinkage is nicely predicted. So reaching Froude numbers 1.0 is now not a problem, along with including an immersed transom on higher speeds, which significantly affects wave-making. Furthermore, this hull form is far from slender forms, it's a huge improvement that the modified thin-ship theory can handle it.

We've started the journey with the novel hull resistance solver, which soon will be enriched by adding a solver for the dynamic equilibrium (trim and sinkage). This will be the fastest validated CFD solver for vessels, that is also runnable inside the browser.

In between tests of the equilibrium solver, we're going to add already tested propulsion calculators. The first in the row is the Wageningen B-series calculator, which dynamically outputs the characteristics. Next follows Gawn, KCA, and optimizers.

By the way, we get a lot of feedback concerning the resistance. Please feel free to share your ideas and wishes for the propulsion, seakeeping, etc.!

Now the resistance calculator more accurately implements the boundary layer and wake effects on the wave resistance. In addition, we've added the initial implementation for demihulls! Please see the changelog. Coming soon: Rhino plug-in, dynamic trim and sinkage to reach high displacement speeds, and then planing speeds!

Per your requests, the Rhino plug-in is on its way. This year is going to be full of surprises with new features implemented in both online versions and within Rhinoceros.