What is subsonic nozzle?

At subsonic speeds (Ma<1) a decrease in area increases the speed of flow. A subsonic nozzle should have a convergent profile and a subsonic diffuser should possess a divergent profile. Divergent nozzles are used to produce supersonic flow in missiles and launch vehicles.

What is supersonic nozzle?

A convergent-divergent nozzle with a variable area and profile through which the relative airflow is supersonic. An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc.

What do you mean by characteristic line in case of supersonic flows?

In a supersonic flow at every point there can exists small disturbance waves called Mach Waves. These are, in fact, the characteristic lines. The Direction of Mach Waves is the characteristic direction. Across a characteristic line, velocity derivatives may be discontinuous, but velocity itself will be discontinuous.

What is Mach number at Exit?

Nozzle Exit Mach number can be defined as the Mach number of the flow leaving the exit of the convergent, divergent nozzle. Isentropic flow tables can be used to calculate this Mach number for a specific convergent-divergent nozzle design.

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.

How do converging diverging nozzles work?

A converging diverging nozzle is placed after a subsonic combustion chamber to take the high temperature, high pressure gas, and transform it into an atmospheric pressure, high velocity gas that will provide thrust through its high momentum.

How do supersonic nozzles work?

The expansion of a supersonic flow causes the static pressure and temperature to decrease from the throat to the exit, so the amount of the expansion also determines the exit pressure and temperature. The exit velocity, pressure, and mass flow through the nozzle determines the amount of thrust produced by the nozzle.

What is prandtl Meyer angle?

In aerodynamics, the Prandtl–Meyer function describes the angle through which a flow turns isentropically from sonic velocity (M=1) to a Mach (M) number greater than 1. The maximum angle through which a sonic (M = 1) flow can be turned around a convex corner is calculated for M = .

How to design a minimum length supersonic nozzle?

The design of minimum length supersonic nozzle is capable of producing minimum length nozzle by contracting the expansion section. With the contraction of the expansion section, the total length of the nozzle reduces. In the above design, the length of the supersonic nozzle is minimum, since the expansion section is minimum.

What is the Mach number of a nozzle?

All of these variables depend on the design of the nozzle. The smallest cross-sectional area of the nozzle is called the throat of the nozzle. The hot exhaust flow is choked at the throat, which means that the Mach number is equal to 1.0 in the throat and the mass flow rate m dot is determined by the throat area.

What determines the exit velocity and exit temperature of a nozzle?

The exit temperature determines the exit speed of sound, which determines the exit velocity. The exit velocity, pressure, and mass flow through the nozzle determines the amount of thrust produced by the nozzle.

How do you find the exit Mach number?

The area ratio from the throat to the exit Ae sets the exit Mach number: A/A* = { [ (gam+1)/2]^- [ (gam+1)/ (gam-1)/2]} / Me * [1 + Me^2 * (gam-1)/2]^ [ (gam+1)/ (gam-1)/2] Solving for the exit Mach number when we know the exit area ratio is quite difficult. But, we can use a computer program to iteratively solve the equation.