Why does velocity increase in divergent nozzle?

In divergent portion of nozzle , specific volume of fluid increases at a higher rate than the crossectional area along the divergent portion. So to maintain constant mass flow rate (M=A*V*density), velocity of flow increases reaching Mach numbers greater than one.

What is the difference between convergent nozzle and divergent nozzle?

Nozzles can be described as convergent (narrowing down from a wide diameter to a smaller diameter in the direction of the flow) or divergent (expanding from a smaller diameter to a larger one).

What is the advantage of convergent-divergent nozzle?

In convergent-divergent type of nozzles we can increase the flow velocity much higher than sonic velocity that is why these type of nozzles have a wide applications such as propelling nozzles in jet engines or in air intake for engines working at high rpms.

What is the maximum velocity that can be obtained in a converging nozzle?

A convergent nozzle can generate maximum sonic speed, Mach = 1. A convergent-divergent nozzle can generate supersonic speed, Mach >1, Therefore, a convergent-divergent nozzle can produce much more vacuum in a given system than a convergent 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.

What is the maximum Mach number at the exit of a converging nozzle?

1
When flow is choked, the Mach number no longer increases and is capped at M = 1. In the case of a converging nozzle, the exit of the nozzle corresponds to the nozzle throat (as seen in Figure 1); therefore, the Mach number right at the exit does not exceed 1, i.e., the flow never goes supersonic.

Is there a maximum achievable Mach number in a convergent divergent nozzle?

Maximum Mach number achievable in a converging nozzle is unity. For supersonic Mach numbers, a diverging section after the throat is required. However, a diverging section alone would not guarantee a supersonic flow.

What is 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 throat size is chosen to choke the flow and set the mass flow rate through the system.

What are the different types of nozzles?

Two types of nozzle are considered: the ‘convergent nozzle’, where the flow is subsonic; and the ‘convergent divergent nozzle’, for supersonic flow. Nozzle Critical Pressure Ratio: When Outlet pressure p 2 equal to or less than p c, i.e. r ≤ r c the following equation applies;

What happens when a fluid flows through a nozzle?

So when a fluid flows through a nozzle, its velocity increases continuously and pressure decreases continuously. 2. Some Applications of a Nozzle: 1. Nozzles are used in steam turbines, gas turbines, water turbines and in jet engines, Jet propulsion.

How do you find the mass flow rate in a nozzle?

Mass-Flow Rate in a Nozzle: The steady flow energy equation is: If P 1 = P 2 the mass-flow rate is zero. Also if P 2 = 0, the mass flow rate is zero. If the graph is plotted for mass flow rate v s pressure ratio, it will be as shown in the figure.