What does a variable nozzle do on a jet engine?

What does a variable nozzle do on a jet engine?

A numerical analysis of the internal flow field in an exhaust converging-diverging nozzle of a jet engine has been carried out. Variable area nozzle is required in a jet engine for optimal expansion and adjusting back pressure in the engine when the afterburner is operated.

When jet engines use afterburners engines are Mcq?

Explanation: When afterburners are not used in jet engines they are dry. Exhaust gases are dry which makes jet engine dry. 7. Afterburners are not equipped with case and liners.

Why we use converging and diverging nozzle?

A converging diverging nozzle is generally intended to produce supersonic flow near the exit plane. If the back pressure is set at (vi), the flow will be isentropic throughout the nozzle, and supersonic at nozzle exit.

What is the function of the nozzle in a jet engine?

All jet engines have a nozzle which produces the thrust as described on the thrust equation slide. The nozzle also sets the total mass flow rate through the engine as described on a separate slide. The nozzle sits downstream of the power turbine and, while the nozzle does no work on the flow, there are some important design features of the nozzle.

What are variable area nozzles used for?

Nozzles whose diameter can be adjusted during flight, known as variable-area nozzles, offered one of the best options for rapidly adjusting the thrust of a jet engine without changing engine speed. Variable-area nozzles are necessary for the use of afterburners and improve engine efficiency during normal cruising situations.

What do all jet engines have in common?

There are several different types of jet engines, but all jet engines have some parts in common. All jet engines have a nozzle which produces the thrust as described on the thrust equation slide. The nozzle also sets the total mass flow rate through the engine as described on a separate slide.

What determines the exit velocity of a gas nozzle?

As shown on this slide, the exit velocity depends on the nozzle pressure ratio and the nozzle total temperature. The nozzle pressure ratio depends on the exit static pressure and the nozzle total pressure. We can determine the nozzle total pressure from the free stream conditions and the engine pressure ratio, EPR.