The pressure nozzle tip for the 4BC2 is a stainless steel injector tip that is found on some Subaru vehicles. The tip can be replaced with models that are made from brass or steel.
Critical pressure in a nozzle is the pressure at which the flow of material through the nozzle reaches its maximum. Beyond which any increase in pressure will not result in an increase in flow. The point at which the velocity of a fluid in the throat of the nozzle reaches the local speed of sound, creating a sonic wave, or a sonic choke.
How to calculate the ratio of the inlet-to-exit area of the nozzle
By Bernoulli's principle velocity head x pressure head is always constant So as velocity increases at the nozzle the pressure falls down automatically.
Pressure build up due to restricted orifice.
The Injector nozzle consists of a needle valve and a series of fine orifices in the nozzle tip. Its task is to inject fuel in an atomised spray pattern and distribute it into the combustion space.
by rotating the ring which cover the opening of the nozzle
To increase the exhaust velocity. +++ Pressure, not velocity. A gas flowing through a divergent nozzle gains pressure at the cost of speed.
To increase thrust or pressure
A nozzle is a device which increases the velocity of fluid by decreasing the Pressure but contrary to it Diffuser is a device that increases the Pressure of fluid at the expense of its velocity
in reaction turbine pressure compounding is employed as every stage has a set of nozzle ring nozzle control is not feasible.
Generally this happens because of the amount of gas flowing from the nozzle. The nozzle "trips" due to back pressure. When the tank is full, gas pushes back on the nozzle and it shuts off. If the amount of fuel coming out of the nozzle fills up the filler tube going to your tank it also will cause back pressure and shut off the nozzle.
It doesn't. It stops when the tank is full. Assuming you are asking why the gas nozzle shuts off when the tank is full, I am not an engineer but I would guess that there is some type of pressure sensor in the nozzle that reads back pressure coming from the neck of the vehicle fuel tank and when that pressure reaches a certain point, it shuts the nozzle off.