Convergent and divergent nozzles >>>3

A steam nozzle may be defined as a passage of varying cross-section,through which heat energy of steam is converted to kinetic energy.its major function is to produce steam jet with high velocity to drive steam turbines.

a nozzle is a device used to convert pressure energy into kinetic energy.Nozzles may not be converging in section always..the property of flow decides the design of the nozzle.for flows which have Mach no. value<=1,nozzle is of converging section.but the same nozzle acts as a supersonic diffuser for flows having mach number>1;similar is the case with the diffusers which are used to convert kinetic energy of the flow into pressure energy.Steady flow energy equation/analysis helps to determine the velocity at the nozzle exit.moreover back pressure plays an important role in the exit plane velocity.for a converging diverging nozzle,sonic velocity is obtained at the throat and for a converging nozzle,it appears at its exit plane.