Grivo JetStar

by Volker Gries

"State of the art high performance Water Jet Propulsion"

Starting with the facts about today's so called Waterjets.These Waterjets are just centrifugal/impeller pumps that accelerate the water to limited nozzle speed of about 80 knots, (45 m/sec.) With every knot (0.514 m/sec.) the vessel increases her speed; the nozzle speed loose this quantity. Meaning, has the vessel reached 40 knots (20.6 m/sec.), the water jet nozzle speed of 80 knots declined 40 knots, while the vessels resistance increases dramatically. As we know, the nozzle speed is in this devices limited, and we can only get more thrust by pumping more water. Mass x Speed is thrust with reference to the 3rd law of motion by Isaac Newton.

In case we use for more thrust a larger water jet, the engines have to be also larger, as well as the tanks. The vessel becomes heavier, the resistance increases, and it is often no more as fast as before, a difficulty without end.The problem is the restricted nozzle speed and water flow.

This problem has been solved by the "Grivo JetStar", a waterjet that works on basic of the patented High Performance Displacement pump "Grivo Star Pump". This pump works like an infinity piston in an infinity cylinder. We can easily reach 200 knots (103 m/sec.) nozzle speed, and have no problem with nozzle speed loss, as above mentioned. We push just a little the throttle. It is a real Waterjet. The limits are material limits, or set by common sense.

The "Grivo JetStar" is the only real innovation in ship propulsion!

It has tremendeous more power in comparison with any today’s so called Waterjets, which represent  a system that was invented in the17th Century, exactly in the year 1660, by Toogood and Hays. The Grivo JetStar was invented by Volker Gries in the 21th Century, an overdue innovation, Just see and use the offered Excel calculation as mentioned below!





Above Excel "Jet Calculation Program" (on request - unlocked*) that gives all the answers regarding Jet Size, Thrust, Nozzle Size, Water Mass, needed Engine Power, etc.



The “old” quotation: “A bumble bee can not fly, but it flies anyway”, is a nice reminder that I send to some experts, and some other experts. This system has never been build before. You cannot use your self written water jet software or similar related calculation methods, and particular water jet experience. Just see it as a high speed piston pump in connection with Isaac Newton’s 3rd law of motion, and you are on the right way.

Volker Gries