Voith Linear Jet
A New Propulsion Standard
The Voith Linear Jet (VLJ) is a fully submerged customshaped deceleration/acceleration nozzle with a stator section aft of the rotor. The stator section cancels rotor-induced swirl, and through that, optimizes the acceleration of the jet stream and the rudder inflow. The submerged position eliminates the requirement for a long inlet tunnel resulting in linear in- and outflow and low marine growth sensitivity.
The resulting benefits of this natural flow path without redirections are increased efficiency and reduced noise and vibration levels. For each vessel application a thorough hull integration study is performed and in combination with the special nozzlefastening mechanism, it maximizes nozzle thrust generation and minimizes nozzle drag up to high speeds.
The Voith Linear Jet combines the best properties of propellers with the best properties of waterjets. Low installation complexity, low sensitivity to marine growth, sustained high efficiency across the vessels' speed range and high bollard pull are borrowed from the propeller side. Reduced vessel draft, the ability to reach high speeds with high efficiency and low noise and vibration levels are borrowed from the waterjet side.
Contact
Voith Turbo GmbH & Co. KG
Alexanderstraße 2
89522 Heidenheim, Germany
Postfach 2011
89510 Heidenheim, Germany
Tel. +49 7321 37-4099
Fax +49 7321 37-7580
vspmarine@voith.com
Application Examples
The main application envelope of the Voith Linear Jet is between 25 and 40 knots. Outside this speed range other features like the reduced draft versus a propeller or a higher bollard pull can make the Voith Linear Jet the preferred option.
Wind service support vessel
Wind service support vessel
Bollard pull, maneuverability and transit efficiency are main operational requirements for a workboat like a wind service support vessel. Optimized nozzles for bollard pull are available in the VLJ range. To obtain favorable transit efficiency with these high-bollard pull nozzles, a vessel-optimized hull integration study is standard for these applications. The high VLJ bollard pull values with the favorable transit efficiency allow vessel operation in higher sea states and increase the vessel's effective operational hours per year. When increased bollard pull and transit speed values are not required, then a one-size smaller engine may be considered.
Yachts
Yachts
Draft reduction to experience all parts of the Caribbean, low noise and vibrations and increased vessel range resulting from the high VLJ efficiency are some of the advantages that the Voith Linear Jet delivers for yachts. If high sailing speeds are preferred, the Voith Linear Jet will easily serve these requirements with a continued comfortable ride at low noise and vibration levels.
Fast ferries
Fast ferries
Fuel burn reduction and fast berthing in port maximizing the number of daily departures will make your ferry service profitable. The low VLJ installation complexity increases availability and lowers maintenance costs. A study conducted for a 4 x 2 880 kW, 30-knot ferry comparing traditional waterjets with the Voith Linear Jet showed a total 804 kW lower power requirement for the Voith Linear Jets. With a fuel burn of 220 g per kWh and a fuel price of US$ 750 per ton, the fuel costs for 2 500 annual operation hours is reduces to US$ 331 650. The time required for safe approach of the jetty is minimized with navigation and yaw rate signals linked to the thrust allocation algorithms.
Navy and coastguards ships
Navy and coastguards ships
Navy and coastguard operations require flexibility. The Voith Linear Jet delivers this with continued high efficiencies at loitering speeds and at top speeds up to 40+ knots. The enhanced sailing range and mission capabilities will serve the vessel's versatility and usability. Low marine growth sensitivity maintains performance at a continued high level. The VLJ discharge under the waterline reduces the acoustic signature.