A quieter and more efficient propulsion system for naval and coastguard vessels
Modern propulsion systems for maritime applications in naval, coastguard and rescue operations have to meet stringent requirements: They should help vessels cover a long distance, enable maximum efficiency at both high and low speeds, and cause minimal noise emissions. Thanks to its innovative design principle, the Voith Linear Jet (VLJ) is ideal for meeting these core requirements while providing vessels with greater operational flexibility.
What is special about the design principle is that the VLJ combines the advantages of traditional propellers with the best properties of conventional water jets. The VLJ is designed with few moving parts, making it robust, reliable, easy to maintain and cost efficient. This type of vessel propulsion system is also the basis for low-noise operation.
Furthermore, the hydrodynamically optimized rotor encapsulated by the nozzle also reduces a substantial proportion of noise emissions and vibrations at any speed. The nozzles of the VLJ are designed to generate a high static thrust while ensuring a consistently high level of efficiency over the entire speed range up to around 40 knots. The stator section aft of the rotor linearizes the rudder inflow and allows safe and precise maneuvering in rough seas. Even at high speeds, the VLJ ensures that the vessel can maintain an extremely stable course.
When integrating the VLJ into a new ship’s hull, Voith works closely with the customer, using tools like computational fluid dynamics (CFD) and its in-house flow channel and drawing on its expertise acquired from close collaboration with maritime research institutes. Since as far back as 2006, Voith has also been using the most modern virtual towing tank in the industry. It allows the simulation of 3D models of the hull in original size. This enables the best position for the VLJ in the hull to be determined, for example, to keep the draft of the vessel as low as possible and therefore facilitate the use of such ships in shallow waters.
The VLJ is available in different sizes, with the ideal size determined by the interplay between the vessel’s engine power and design speed. The VLJ gets its power from a diesel engine or electric motor. Voith has also gained good experience with hybrid propulsion systems. These variable propulsion options are one of the reasons why numerous customers around the world are already using the VLJ in their maritime applications.
