Orca3D Powers Naval Research Presented at RINA Warship 2025

Author: Larry Leibman

We’re excited to announce that research using Orca3D Marine CFD was recently featured at the RINA Warship 2025 Conference, an international event focused on the future of naval ship design and marine innovation. 

 The paper, titled “On the Benefit of Adjustable Stern Energy Saving Devices for Fast Warships,” was presented by Dr. Stefano Brizzolara of Virginia Tech in collaboration with Fincantieri Marinette Marine. The study looked at how small changes to a ship’s sterncan lead to big improvements in fuel efficiency and performance. 

And the simulations that powered these insights? They were all done using Orca3D Marine CFD, our tool that helps engineers test how ships move through the water—right on their computers. 

Why Focus on the Stern? 

Warships today are built for speed and power. Most of them have a “transom stern” design—essentially a squared-off back end that’s great for space and speed, but not always the most efficient at lower cruising speeds. That’s a problem because naval vessels spend most of their time cruising, not sprinting at top speed. 

 To solve this, engineers have experimented with different add-ons at the stern to help reduce drag and improve how the ship rides in the water. These include: 

  • Fixed wedges and flaps that stick out and help lift the stern 

  • Adjustable interceptors, which can move up and down depending on the ship’s speed and needs 

This study set out to see which of these options works best—and when. 

Orca3D Marine CFD Brings Designs to Life 

To test these ideas, the team used Orca3D Marine CFD to simulate how a 142-meter-long warship would perform with different devices installed at the stern. These computer-based tests—also called “virtual towing tank” simulations—let engineers see how water flows around the ship, how much drag it creates, and how the ship's position in the water changes at different speeds. 

Figure 1) Free wave patterns calculated using Orca3D at high speed. 

What They Found 

The results were clear: 

  • The adjustable interceptor outperformed the fixed devices. When extended, it helped reduce drag by up to 6% at high speeds, and it also improved how the ship’t pitch angle—lifting the stern and reducing resistance. 

  • Fixed wedges provided a small benefit at mid-range speeds, but actually added drag at low speeds. 

  • Because the interceptor can be adjusted depending on speed, it delivers savings across the ship’s full range of operations, not just at one “sweet spot.” 

Figure 2) Resistance change (negative = reduction) predicted for different energy saving devices versus speed. The cyan dotted line represents the best performance of an adjustable interceptor 

Why It Matters 

Saving 4–6% on fuel might not sound huge—but for a warship operating around the clock, those savings can add up to millions of dollars per year in fuel and maintenance, not to mention reduced emissions and improved mission range.What’s even better? These improvements were all discovered without building a single physical model. Thanks to Orca3D Marine CFD, the team could test, adjust, and compare designs virtually—saving time, money, and materials. 

What Orca3D Can Do for You 

Whether you’re designing high-speed warships, commercial ferries, or small craft, Orca3D Marine CFD gives you the power to analyze and optimize performance early in the design process—before you ever hit the water. 

👉 Request a free trial to try Orca3D Marine CFD for yourself 
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