Can a shock develop in the converging section of a converging diverging nozzle explain in your own words?

Can a shock wave develop in the converging section of a converging– diverging nozzle? Explain. Solution: No, because the flow must be supersonic before a shock wave can occur.

What happens to the sound speed as the flow goes through the converging diverging nozzle with supersonic flow at the exit?

The general design of a converging-diverging nozzle is such that the initially low speed gas is accelerated as it is squeezed into the throat (with minimum diameter) at which it reaches the speed of sound. It is then accelerated further as it is now a supersonic flow moving through a diverging nozzle.

Under what conditions will the flow through a convergent-divergent nozzle become choked?

When the back pressure ratio is large enough, the flow within the entire device will be subsonic and isentropic. When the back pressure ratio reaches a critical value, the flow will become choked with subsonic flow in the converging section, sonic flow at the throat, and subsonic flow in the diverging section.

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.

Why is a diverging nozzle converging?

What is converging and diverging duct?

Relationship of pressure, temperature, and velocity in a convergent-divergent duct. A duct that has a decreasing cross section in the direction of fluid flow is convergent, until a minimum area is reached. Thereafter, the cross section increases, or becomes divergent.

What happens to a supersonic flow when it passes through a diverging duct?

However, the flow pattern in the diverging section does change as you lower the back pressure further. As pb is lowered below that needed to just choke the flow a region of supersonic flow forms just downstream of the throat. Unlike a subsonic flow, the supersonic flow accelerates as the area gets bigger.

How will the flow change in a converging nozzle for supersonic flow?

The flow accelerates out of the chamber through the converging section, reaching its maximum (subsonic) speed at the throat. Unlike a subsonic flow, the supersonic flow accelerates as the area gets bigger. This region of supersonic acceleration is terminated by a normal shock wave.

What are the converging and diverging?

Divergence generally means two things are moving apart while convergence implies that two forces are moving together. Divergence indicates that two trends move further away from each other while convergence indicates how they move closer together.

What does it mean to diverge or converge?

Converging means something is approaching something. Diverging means it is going away.

What is the typical configuration for a converging diverging nozzle?

The usual configuration for a converging diverging (CD) nozzle is shown in the figure. Gas flows through the nozzle from a region of high pressure (usually referred to as the chamber) to one of low pressure (referred to as the ambient or tank).

How does the back pressure affect supersonic flow?

In this regime if you lower or raise the back pressure you increase or decrease the length of supersonic flow in the diverging section before the shock wave. 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).

What are flows in closed conduits?

Flows in closed conduits or channels, like pipes or air ducts, are entirely in contact with rigid boundaries. Most closed conduits in engineering applications are either circular or rectangular in cross section.

What happens to mass flow rate when back pressure is lowered?

The flow pattern downstream of the nozzle (in the diverging section and jet) can still change if you lower the back pressure further, but the mass flow rate is now fixed because the flow in the throat (and for that matter in the entire converging section) is now fixed too.