With jet engines, it’s relatively easy to light it up and throttle. I know you can’t shut them down mid-flight and then turn them back on while still in the air, but you can easily throttle them. Now with rocket engines, you can only light most engines 1-3 times, and their throttle ability is minimal. Why is this so?
Thanks in advance.
In: Engineering
Solid rocket engines: it’s like lighting a firecracker. There is no off switch.
Liquid rocket engines: they just require a lot of fuel and energy to start up. It’s not that practical. They can control the throttle to an extent. However, they are generally designed for very specific high-output applications (like launching a satellite into orbit) so they don’t generally need to be designed to work in a variety of conditions.
Even from your example with regular jet engines, it actually is not that easy to start them up like a car. It takes a huge amount of power (and time) to get the compression high enough to start producing its own power.
Latest Answers