Why nozzles are made convergent and divergent?
Convergent-divergent type of nozzles are mostly used for supersonic flows because it is impossible to create supersonic flows (mach number more than one) in convergent type of nozzle and therefore it restricts us to a limited amount of mass flow through a particular nozzle.
What type of expansion takes place in a nozzle?
The work done is equal to the adiabatic heat drop which in turn is equal to the Rankine area. The flow of steam through nozzles may be regarded as adiabatic expansion. The steam has a very high velocity at the end of the expansion, and the enthalpy decreases as expansion takes place.
When cross section area of nozzle increases from inlet to outlet is called?
11. Divergent nozzle: The crossectional area of the duct increases from inlet to the outlet then it is called as divergent nozzle. Flow of steam through nozzles: The flow of steam through nozzles may be regarded as adiabatic expansion.
When cross section area of nozzle first increases then decreases from throat to exit is nozzle?
22) 22. When the cross-section of a nozzle first increases from its entrance to throat, and then decreases from its throat to exit, it is not a convergent-divergent nozzle.
Why does the pressure decrease in a convergent nozzle?
In a convergent nozzle, there is an increase in velocity and a decrease in pressure, but we know that pressure is inversely proportional to area. Then why is this pressure decreased in convergent nozzle, although there is a decrease in area? The pressure drops in a convergent nozzle because of the Bernoulli Principle.
What is a convergent-divergent (CD) nozzle?
Rockets typically use a fixed convergent section followed by a fixed divergent section for the design of the nozzle. This nozzle configuration is called a convergent-divergent, or CD, nozzle.
What is under expansion in a nozzle?
An under expansion in a nozzle is where the gas is expelled at a greater pressure than the atmosphere around it, this causes the plume to expand outwards reducing the efficiency of the thrust.
What determines the exit velocity and exit temperature of a nozzle?
The exit temperature determines the exit speed of sound, which determines the exit velocity. The exit velocity, pressure, and mass flow through the nozzle determines the amount of thrust produced by the nozzle.