How do divergent nozzles increase velocity?

How do divergent nozzles increase velocity?

As the back pressure at the nozzle exit is made equal to the pressure required for the flow to fully expand isentropically, the flow accelerates throughout the diverging part of the nozzle and we get maximum velocity.

What is principle of working of a convergent divergent nozzle?

This nozzle configuration is called a convergent-divergent, or CD, nozzle. In a CD nozzle, the hot exhaust leaves the combustion chamber and converges down to the minimum area, or throat, of the nozzle. The exit velocity, pressure, and mass flow through the nozzle determines the amount of thrust produced by the nozzle.

What happens to velocity in the diverging duct?

What happens to velocity in the diverging duct? Explanation: Mass flow rate is given by Q = m/p. This is a relation expressed for mass flow rate. With the presence of a converging duct, the velocity decreases.

When a nozzle is said to be choked *?

The flow rate is maximum for a given nozzle if the flow is sonic at the throat. This condition is achieved by managing the back-pressure. If the mass flow rate is reached the maximum value at the throat then the flow is called choked flow.

How does the steam flow through the convergent divergent nozzle?

Working of Flow of Steam through Convergent-divergent Nozzle: Portion-1: In the convergent portion steam enters the nozzle with a high pressure, but with a negligible velocity, thus there is a drop in the steam pressure with a rise in its velocity.

How does velocity affect the flow rate of a convergent nozzle?

For a nozzle the mas flow rate is equal to density x v elocity x cross sectional area of nozzle. That is: dVA = constant. At low velocities the density is constant and therefore as the area gets smaller (convergent nozzle) the velocity must increase to keep dVA constant.

How to extend supersonic flow down nozzle?

If you lower pbenough you can extend the supersonic region all the way down the nozzle until the shock is sitting at the nozzle exit (figure 3d). Because you have a very long region of acceleration (the entire nozzle length) in this case the flow speed just before the shock will be very large in this case.

What is the variation of steam pressure in the nozzle?

Note: 1. Since the mass of steam which is passes through any section of the nozzle remains’ constant. 2. The variation of steam pressure in the nozzle depends upon the velocity, specific volume and dryness fraction of steam.