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Enthalpy-Entropy diagram of stagnation state. In fluid dynamics, a stagnation point is a point in a flow field where the local velocity of the fluid is zero. The isentropic stagnation state is the state a flowing fluid would attain if it underwent a reversible adiabatic deceleration to zero velocity.
Diagram of a de Laval nozzle, showing approximate flow velocity (v), together with the effect on temperature (T) and pressure (p) A de Laval nozzle (or convergent-divergent nozzle, CD nozzle or con-di nozzle) is a tube which is pinched in the middle, with a rapid convergence and gradual divergence.
The simplest single fluid nozzle is a plain orifice nozzle as shown in the diagram. This nozzle often produces little if any atomization, but directs the stream of liquid. If the pressure drop is high, at least 25 bars (2,500 kPa; 360 psi), the material is often finely atomized, as in a diesel injector.
Figure 1: A de Laval nozzle, showing approximate flow velocity increasing from green to red in the direction of flow Density flow in a nozzle. A rocket engine nozzle is a propelling nozzle (usually of the de Laval type) used in a rocket engine to expand and accelerate combustion products to high supersonic velocities.
The flow then decelerates through the diverging section and exhausts into the ambient as a subsonic jet. In this state, lowering the back pressure increases the flow speed everywhere in the nozzle. [13] When the back pressure, p b, is lowered enough, the flow speed is Mach 1 at the throat, as in figure 1b. The flow pattern is exactly the same ...
Next, the flow follows the Fanno line until a shock changes the flow from supersonic to subsonic. The flow then follows the Fanno line again, almost reaching a choked condition before exiting the duct. Figure 5 Fanno and Rayleigh Line Intersection Chart. The Fanno flow model is often used in the design and analysis of nozzles.
The nozzle is usually convergent with a fixed flow area. Supersonic nozzle — For high nozzle pressure ratios (Nozzle Entry Pressure/Ambient Pressure) a convergent-divergent (de Laval) nozzle is used. The expansion to atmospheric pressure and supersonic gas velocity continues downstream of the throat and produces more thrust.
A nozzle is a device designed to control the direction or characteristics of a fluid flow (specially to increase velocity) as it exits (or enters) an enclosed chamber or pipe. A nozzle is often a pipe or tube of varying cross sectional area, and it can be used to direct or modify the flow of a fluid (liquid or gas). Nozzles are frequently used ...