Wärtsilä has announced that its LJX series of modular waterjets has been upgraded and redesigned as the Wärtsilä WXJ series. This upgrade is said to deliver greater efficiency with low levels of cavitation and underwater noise.
The Wärtsilä WXJ modular waterjets are aimed at various global market sectors, including high-speed ferries, frigates, and other high- speed naval vessels, yachts, shallow draft vessels, large fast crew vessels, and large fast supply vessels.
The development is based on a new axial pump design, which boosts performance with an increased thrust of as much as 3%, while the improved cavitation margins help reduce the environmental impact by lowering noise levels. The increased pump cavitation margin of 35% and the lower impeller tip speed, means more power can be introduced to the pump during manoeuvring. This results in a 15% higher manoeuvring thrust and faster response to acceleration, according to Wärtsilä.
The new WXJ pump has been tested extensively, both in computational fluid dynamic simulation and with model testing. With this successful upgrade, Wärtsilä is now in a position to supply global markets, including China and other Asian countries, with these new and upgraded waterjet solutions.
Leendert Muilwijk, Wärtsilä’s general manager Product Group commented on the upgraded system, “We have been able to keep the notable benefits from the LJX-series, and the interface between the waterjet and the vessel remains identical to that of the LJX. Similarly, the small transom interface dimensions, and best-in-class weight are unchanged, but overall performance is now improved.”
The new waterjets are compact, high performance systems that combine mixed flow properties with an axial construction. This results in much less space being needed on the vessel’s transom, and greatly increased waterjet cavitation margins for optimum vessel operational flexibility. For naval architects, the axial jet technology creates the possibility to apply a larger power density onto narrower hulls to achieve top vessel performance.