Table of Contents
What does the atmospheric pressure have to do with the size of the bell nozzle?
Atmospheric pressure restricts the expansion of the exhaust gas at low altitudes so the efficiency is much higher at low altitudes . At low altitudes, a vehicle can saves 25-30\% more fuel by using a dual bell nozzle.
Does rocket thrust increase with altitude?
At full throttle, the net thrust of a rocket motor improves slightly with increasing altitude, because as atmospheric pressure decreases with altitude, the pressure thrust term increases. At the surface of the Earth the pressure thrust may be reduced by up to 30\%, depending on the engine design.
How does the divergence angle vary along a bell shaped nozzle?
How does the divergence angle vary along a bell-shaped nozzle? Explanation: For a bell-shaped nozzle, immediately after the throat section, the nozzle divergence angle increases rapidly and then it gradually decreases.
What does the nozzle of a rocket do?
A rocket engine uses a nozzle to accelerate hot exhaust to produce thrust as described by Newton’s third law of motion. The amount of thrust produced by the engine depends on the mass flow rate through the engine, the exit velocity of the flow, and the pressure at the exit of the engine.
Why is a bell shaped nozzle used in rocket engines?
However, a shorter bell shape is typically used, which gives better overall performance due to its much lower weight, shorter length, lower drag losses, and only very marginally lower exhaust speed. Other design aspects affect the efficiency of a rocket nozzle. The nozzle’s throat should have a smooth radius.
What makes a rocket go to the highest possible altitude?
The engine that you use in a rocket plays a huge role in the kind of height you can achieve. According to the National Association of Rocketry, what you need to reach higher altitudes is the smallest engine that fits in your rocket with the highest total impulse, the longest time delay, and the lowest average thrust.
Does ambient pressure affect the design of rocket nozzles?
The effect of ambient pressure is clearly significant in the design of rocket nozzles. As will be shown later, staged propulsion, as in the case of the Saturn V rocket which launched the Apollo missions, allows for each stage to use a different nozzle/engine better suited to that operating regime.
How much thrust does a booster add to a rocket?
Each booster provides 12,000kN of thrust at sea level, increasing to 14,000kN before reaching the peak thrust altitude of 46km and separation shortly thereafter. Part of the thrust increase may be related to the lower pressure at high altitude, however in this case I want to call out the shape of the nozzle exhaust.