Search Results

Yes, RR engines typically have 3 spools while GE and P&W generally have 2. There are several design tradeoffs. Briefly: 3 spools are easier for the aerodynamic design. For example, compressor stall …

See this question. It is a single annular combustor (one ring of full nozzles). I think that "twin" refers to the fact that within a single fuel nozzle, there are two different fuel streams: the mai …

I agree with all of the answers posted so far, particularly regarding supersonic speed. Let me add another perspective: Differences in priorities. The major factors influencing engine design are: co …

Float just means that that value will vary depending on ambient temperature pressure etc. It is not controlled. E.g. on n2 control, if n2 goes down then the control puts in more fuel and if n2 goes up …

Referred speed is a way of compensating for the fact that air density changes with temperature. For example, let's say you are designing a new turbojet engine. You fire up your engine one warm sunny …

First let's talk about thrust. Jet engines are designed for very specific thrusts for every specific applications. For example, look at the GEnx-1B versus the GEnx-2B. The Boeing 787-8 has GEnx-1B …

For rockets, specific impulse is constant regardless of speed. For jet engines, specific impulse is very high at zero speed and drops off as velocity increases. At relatively low speeds (say below Ma …

The thing most in need of cooling inside a jet engine is usually the high pressure turbine blades. The air entering the first stage of the turbine is in the neighborhood of 2500F (https://en.wikipedi …

In theory, I think that should be possible, as the -3B is a lower thrust rating than the -3C (going to higher thrust rating would be harder). However, you would have to ask CFM. I think they are the …

There are three primary ways that blades are connected to the shaft Circumferential dovetails Here is a nice site demonstrating it. Includes STL files so you can 3D print your own demonstration pa …

Corrected speed allows performance characteristics of the jet engine to be easily compared across operating conditions, specifically across different ambient temperatures. Let's just say that for a gi …

Well, development of any large high bypass turbofan is something extraordinary. It probably took thousands of engineers and specialists working for many years to develop this engine, with a developmen …

To build upon a few points in Peter's answer: This diagram will probably help visualize it (I copied from this question How is the central hub / shaft casing of a two-spool jet engine assembled?): …

what problems are stopping us from doing this? In some sense, it's business reasons. Developing a brand new jet engine from scratch costs a lot of money. Usually the pricetag runs into the billio …

It's on the order of a few percent. Not huge but not negligible either.