Water jet pressure and speed 100mm from a 2mm nozzle at 400 bar

[JoachimSa]

I am trying to calculate at what pressure and speed water from a high pressure water jet will hit an object 100 millimeters away from the nozzle opening, but i can't figure it out.

The nozzle will be used at approximately 100 meter below sea level in salt water. Its a circular nozzle with a diameter = 2 millimeters. The water from the water jet is at 400 bar and with a flow of about 60 liters per minute.

Does anyone know what formula to use?

 

[mfb]

I don't think there is a simple formula where you could just plug in numbers. There are certainly publications about that setup, you could check what they did to simulate the system.

 

[Nidum]

A turbulent jet of liquid discharged into a large volume of the same liquid spreads out in a cone shape . Tests and simulations have determined that assuming a half angle of 11.8 deg for the cone is adequate for most practical calculations . Problem is that the velocity of flow varies not only with distance from nozzle but also with radial distance from the flow centreline . Velocity is highest on the flow centreline and fades away to zero at larger radial distances .

What actually happens when jet impinges on an object depends on the geometry of the object .

 

[boneh3ad]

This becomes doubly difficult if your water jet is fresh water discharging into salt water, as it is now a turbulent buoyant jet. Generally speaking there is no simple solution to this problem (buoyant or not).