The turbojet tag has no usage guidance.
0
votes
2answers
63 views
Why does a turbine engine compressor ratio affect stagnation pressure?
This might just be a misunderstanding on my part, but in an ideal Brayton cycle, the flow through the compressor and turbine is isentropic, meaning $\Delta s = 0$. However, usually you are given the ...
2
votes
2answers
82 views
How can I determine specific heats of gases for turbojet engine calculations?
I'm in a combustion lab and we are performing experiments on a turbojet engine. However, I am having some trouble calculating the exit velocity and compressor/turbine powers of the engine.
Consider ...
2
votes
2answers
255 views
Can a turbojet jet or turbofan powered aircraft land and take off from water?
Can a turbojet jet or turbofan powered aircraft land and take off from water? How much clearence from the water surface would it need for its engines so that it does not suck up water?
6
votes
2answers
252 views
What exactly does the MB-326's 'relight' button do?
The following picture shows the engine throttle of an Aermacchi MB-326, which is powered by the Rolls-Royce Viper turbojet:
(source - all photos © Drive&Fly Model Club)
I wonder what exactly the ...
1
vote
2answers
74 views
Fans of tubofan jet engines
Does the thrust of the fan in a turbofan jet engine decrease proportionally with decrease in the diameter of the fan?
As the fan in a jet engine is responsible for over 70% of the total thrust can a ...
13
votes
1answer
3k views
Which jet engines have the highest thermal efficiency?
Some automakers (Mercedes-Benz, Toyota) have recently been making news about the improved thermal efficiency of their engines, stating that they reached the 50% mark. I was wondering if it was the ...
2
votes
1answer
564 views
Are there any differences between turbofan and turbojet engines besides bypass air?
I think I understand both engine types, but I am just wondering am I right in saying that the only difference between the two types of engines is the bypass air (i.e. a turbofan is just a turbojet ...
9
votes
2answers
480 views
Why were turbojets the first kind of turbo-engines, instead of turboprops?
During WW2, the first jet engines appeared en mass in combat aircraft. Britain and Germany made the first ones.
But why were turbojets first? Why not turboprops, which are easier since the turbo-...
3
votes
2answers
390 views
Are there turbofan/turbojet analogues to a centrifugal-compressing jet engine?
Axial-compressor jet engines fall into two categories (and only two as far as I'm aware): turbofan and turbojet. I'm wondering if centrifugal-compressor jets also have such a distinction or something ...
0
votes
1answer
535 views
How small can turbojet engines be made whilst remaining fuel efficient, light, cheap, and producing enough thrust to carry a human, gas, and casing? [closed]
I've seen many videos of small turbojet engines (small enough to hold in your hands) that produce 30-40 pounds of force. If you mounted a couple of these on a small craft, that wouldn't even support ...
6
votes
1answer
172 views
Why is a turbofan engine less efficient when air leaks over fan blade tips?
Image source
I understand part of the reasoning for minimal clearance between the casing and the fan blades, is to have the larger fan blade possible, which generates a larger low pressure area to ...
3
votes
2answers
142 views
What structural design methods were used for early turbojets?
I have had this question for long time. Can anyone please give me some references on early turbojet engine design methodologies?
For example P&W J57 which was designed in early 1950's: How were ...
1
vote
2answers
111 views
Is there a way to calculate thrust without running experiments?
Is there any way to calculate the thrust generated without conducting experiments? In my case I need to figure out thrust generated by electric duct fans and/or turbojets.
4
votes
1answer
307 views
What is the actual exhaust velocity of the exhaust from the J58 engines at cruise (Mach 3.2)?
The SR-71 ran on two J58 turbojet engines and cruised at Mach 3.2.
What I want to know is, what is the actual exhaust velocity (relative to the airplane itself) of the jet exhaust at those conditions?...
1
vote
1answer
218 views
Are there cases of a thrust reverser used on a turbojet engine?
In the case of a turbojet (with no "cold" bypass flow), the airflow being directed forward by an hypothetical thrust reverser can be really hot.
Depending on the location of the engine, this flow may ...
