Waterjet propulsion solutions - Laboratory of Marine Engineering

Rodriquez TMV84 with 4 x LJ91E waterjets.Optimized efficiency: CFD calculationsComputational Fluid Dynamics (CFD) calculationsrevolutionize the hydrodynamic optimization process of thewaterjet. With CFD we can optimize every waterjet installationwe supply for the specific design requirements defined by thenaval architect. We have developed a highly advanced CFDmodel of our waterjets that is capable of analyzing everyoperating condition fast and at low cost. Our CFD model hasbeen validated in hydrodynamic research centres around theworld.Safety: reduced risk of cloggingThe Lips jet has only 7 stator blades in the jet bowl after theimpeller compared to 11 or more in other designs - anotherpositive spin-off of our inboard thrust bearing. In our design,the "crash-stop" forces acting on the thrust bearing are nottransferred to the stator section of the jet, which allows fewerstator blades. The low number of stator blades in Lips jetssubstantially reduces the risk of cloggingSafety: manoeuvrability,acceleration and crash stopWaterjets offer excellent manoeuvrability from zero to full shipspeed, good acceleration and excellent crash-stop capabilities.Special reversing designs can enhance these features evenfurther.Comfort: low noise and vibrationsNoise and vibrations and hydro-acoustic noise are far lower forwaterjets than for propellers. This improves passenger comfortand reduces the signature of a naval vessel.Easy maintenance and serviceKey factors in successful operation include low maintenancecosts and reliable service without downtime and delay due tomechanical problems. To achieve this we have designed our jetsto avoid complex oil-lubricated mechanical components outsidethe vessel and with a philosophy focused on limiting the totalnumber of moving parts.To reduce the maintenance costs even further we haveintroduced standard maintenance sets for all main mechanicalmaintenance jobs. To find what is needed to overhaul a6