Perfecting propulsion

The foundation for the success of our naval propulsion range is the Kongsberg Hydrodynamic Research Centre (HRC) in Kristinehamn, Sweden, on the shores of Lake Vänern.

The HRC is one of the world’s leading marine research facilities, specialising in the development of marine propulsion systems including the design and testing of propellers and waterjets.

Patrik Kron, our Chief of Naval Systems, explains how this unique research facility continues to play a key role in developing bespoke propulsion solutions to 70 navies worldwide.

The Kongsberg Hydrodynamic Research Centre (HRC) puts us at the forefront of marine technology research and makes a significant contribution to the efficiency and mission-critical performance of many of the world’s navies.

The HRC features two cavitation test tunnels, where water is circulated to assess the performance of a ship’s propulsion system. The tunnels simulate a wide range of vessel operating conditions, replicating different sea parameters, water flows and situations for the propulsor.

We are unique in that we are the only propulsion manufacturer to have our own in-house research facility. This gives us a number of advantages that are popular with commercial and naval customers alike. We can take close control of the full testing regime, we can react quickly to design changes and it gives us an additional form of verification.

We have developed, tested and delivered more than 1,500 propeller designs for commercial, governmental and military vessels. Our engineers develop propeller designs digitally using the latest computational fluid dynamics (CFD) technology. Such is the computing power available at the HRC, propellers can be modelled in minute detail and in combination with the hull form and operating profile of any ship. We also create scale models of propellers, which are tested in the tunnels, and this gives extra validation on the performance of new designs. 

Depending on the results of these tests, propeller profiles can be altered and refined to give optimum designs suited to specific vessels and operating conditions.

Each navy has its own distinct requirements and while we can draw on a huge amount of data, the propellers we produce for navies are bespoke items and not off-the-shelf solutions as is sometimes the case in the commercial shipping environment.

The propeller design is adapted to the size of the ship, its speed, noise and vibration requirements and whether it needs to be able to go through ice. For navies, the sound signature of the propulsion system can be a key factor, as can the speed requirements. Often, there is a need to finely balance these requirements and we work closely with our naval customers to develop propellers that match their specific mission requirements. 

Fuel efficiency is also becoming a more important issue for navies, more so than it was just a few years ago. We can learn from the work we’ve done in commercial shipping, where fuel cost reduction is a priority, and small changes to propeller designs and operating profiles can bring relatively quick savings. For navies, any fuel saving translates into a key capability – range extension. Our Promas propulsion system (see pages 22 and 23) is a great example of where a product with more than 200 references in commercial shipping can bring benefits for certain naval platforms.