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The convergent nozzle was replaced with a C-D nozzle on the same engine J57 in the same aircraft F-101. The increased thrust from the C-D nozzle (2,000 lb, 910 kg at sea-level take-off) on this engine raised the speed from Mach 1.6 to almost 2.0 enabling the Air Force to set a world's speed record of 1,207.6 mph (1,943.4 km/h) which was just ...
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. It is used to accelerate a compressible fluid to supersonic speeds in the axial (thrust) direction, by converting the thermal energy of the flow into kinetic energy .
The optimal size of a rocket engine nozzle is achieved when the exit pressure equals ambient (atmospheric) pressure, which decreases with increasing altitude. The reason for this is as follows: using a quasi-one-dimensional approximation of the flow, if ambient pressure is higher than the exit pressure, it decreases the net thrust produced by ...
The nozzle area is increased to accommodate the higher specific volume of the exhaust gas. This maintains the same airflow through the engine to ensure no change in its operating characteristics. Exhaust or nozzle — Turbine exhaust gases pass through the propelling nozzle to produce a high velocity jet. The nozzle is usually convergent with a ...
The rectangular convergent-divergent nozzle is fully variable for both the convergent throat and divergent areas for high nozzle pressure ratio and can vector ±20° in the pitch axis, greatly improving the aircraft's pitch authority by augmenting the pitching moment of the tail with engine thrust; this enables the F-22 to remain controllable ...
Schematic of a cold gas propulsion system. The nozzle of a cold gas thruster is generally a convergent-divergent nozzle that provides the required thrust in flight. The nozzle is shaped such that the high-pressure, low-velocity gas that enters the nozzle is accelerated as it approaches the throat (the narrowest part of the nozzle), where the gas velocity matches the speed of sound.
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). A de Laval nozzle has a convergent section followed by a divergent section and is often called a convergent-divergent (CD) nozzle ("con-di nozzle").
The pressure entering the nozzle may vary from 1.5 times the pressure outside the nozzle, for a single stage fan, to 30 times for the fastest manned aircraft at Mach 3+. [ 32 ] Convergent nozzles are only able to accelerate the gas up to local sonic (Mach 1) conditions.