Why is it that variable geometry nozzles, like those found on jet engine(iris nozzles), are not used as rocket nozzle to provide better altitude compensation?
anorlunda said:This video does not directly answer your question, but it talks a lot but altitude compensation.
Thank you. Yup that makes sense. If the cost saved by the increase in efficiency does not enough justify the cost of implementation of such a nozzle.boneh3ad said:While I'm not a rocket designer, I'd hypothesize that it has to do with the cost-benefit analysis of implementing something like that. They'd get more efficient operation, but it would require increased weight, more exotic materials, and (until recently) would only be used once. That's a lot of cost to justify a relatively small benefit.
Variable geometry nozzles, also known as adjustable nozzles, are not used on all rocket engines due to several reasons. One reason is that these nozzles add complexity and weight to the engine, which can impact the overall performance and cost of the rocket. Additionally, variable geometry nozzles may not be necessary for smaller rockets or for missions that do not require precise control of thrust.
The main benefit of using variable geometry nozzles is the ability to adjust the nozzle's shape and size during flight, which allows for more efficient use of the rocket's propellant. This can result in increased thrust and improved performance, especially in high-altitude or low-pressure environments.
One of the main disadvantages of using variable geometry nozzles is the added complexity and cost. These nozzles require additional mechanisms and controls, which can increase the risk of failure and add to the overall cost of the rocket. Additionally, the added weight of the nozzle can also impact the rocket's performance.
While variable geometry nozzles can be used on various types of rocket engines, they are more commonly used on liquid-fueled engines. This is because liquid propellants can be easily controlled and manipulated, allowing for more precise adjustments of the nozzle. Solid-fueled rockets, on the other hand, have a fixed nozzle design that cannot be adjusted during flight.
Yes, there are other alternatives to variable geometry nozzles for improving rocket engine performance. One example is using multiple nozzles on a single engine, which allows for more control and flexibility of thrust. Another alternative is using a bell-shaped nozzle, which can provide more efficient thrust in high-altitude environments. Additionally, advancements in materials and design have also allowed for more efficient and lightweight nozzles, which can improve performance without the added complexity of variable geometry.