Questions tagged [engine-design]
Questions about the process and principles used when designing aircraft engines. Use "jet-engine" and "piston-engine" tags to specify a certain type of engine.
21
questions with no upvoted or accepted answers
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Engine Bearings Damage in Radial Engines
Studying the P47's dive performance in DCS, I noticed how it's easy to damage the engine bearings if you windmill the prop at high speed.
Doing some research, I discovered that all radial engines are ...
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Why isn't Yamaha EPeX300Ti more popular in aviation?
The answer to this question might be obvious to experienced aviators. But as an armchair enthusiast, I really couldn't find a satisfactory answer anywhere on the internet.
Below two pages came from ...
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RR Ultrafan: Why the dramatic change of fan blade design?
The Rolls Royce Ultrafan prototype has been in development for a few years and has usually been seen in the media with very distinctive curved leading edge design as such:
However, this week (...
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What different intake designs are there, and what are their pros and cons?
I noticed that over the years (on fighter jets specifically) there have been many different methods of directing air into the engines. Primarily, the nose-intake, side intake, and underbody intakes ...
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Could injectors be used as an alternative to turbopumps in jet engines?
Could injectors be used instead of turbopumps in aeroengines? Are there jet engimes that already use them?
https://en.m.wikipedia.org/wiki/Injector
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2
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537
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How hot is the outer casing of a turbofan engine?
I am able to find temperatures inside different components of turbofan engines, but I can't seem to find what would be the temperature of the external casing/shell of the engine. For example, ...
- 41
2
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157
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Do rotating deflagration engines exist?
Pulsejets (which could have been called pulse deflagration engines) rely on pulsed deflagration to generate energy and thrust. Their pulsed mode makes them hideously loud and rather inefficient, but ...
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2
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1
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676
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On a small/micro jet engine, can the turbine blades and vanes be made out of ceramic?
I am researching on how to make a small jet engine, and trying to figure out the materials for rotor and stator blades just after the combustion chamber so that they can hold up to the temperatures ...
- 21
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Why pressure and temperature decreases along the length of a convergent nozzle?
I know that the pressure and temperature follows stagnation relations of pressure and temperature as well as area mach relation inside a convergent nozzle along the length. And according to that ...
1
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0
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129
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Why doesn't the -30% SFC fully account for the dramatic reduction in fuel consumption compared to the 1960s?
In looking at the specific fuel consumption (SFC) of some aero engines I find that for example, the Rolls Royce Conway turbofan engine had typical cruise SFC of 0.874 lb/(h lbf) whilst the most modern ...
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Does an increase in Mach number lead to a decrease in Total Pressure Recovery (TPR) for supersonic inlets?
I am curious if the total pressure recover for supersonic inlets, in general, decrease for an increase in Mach number.
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Texts on aero-engine structures
I have been scouring the web for resources on aero-engine structures and structural design (preferably civil turbofans) but unfortunately it seems like they are hard to come by. I would like dedicated ...
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317
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How to avoid shock (particularly Oblique shock) inside Cd nozzle?
Using the Area ratio (A/A*) and for the desired exit Mach number I have designed a cd nozzle. The Inlet total pressure (Po) and the total temperature (To) is calculated using Isentropic relations for ...
- 33
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148
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How does a partially covered air intake affect the thrust of a propeller ?
does a partially covered air intake of a ducted propeller significantly affect its thrust?
If so, will it be like 10 or rather 90 percent less thrust ?
Thanks for your answers!
Simon
- 351
1
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Do plug nozzles improve efficiency on lower throttle settings?
Plug nozzles are used to adjust for the overexpansion/underexpansion of the exhaust with altitude. Do they also adjust for overexpansion/underexpansion of the exhaust caused by lowered mass flow ...
- 2,484
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38
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Do we use static pressure in thermodynamic cycles like brayton instead of total pressure?
I observed that pressure plotted in the graph above increases from 0 to 1.
0 is inlet entrance and 0' (not shown in the graph) somewhere between 0 and 1 is compressor entrance.
Now, we know that at ...
- 244
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138
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What should the inlet to throat area ratio be for a CD rocket nozzle on an aircraft flying at Mach 10?
I am analysing a rocket CD (convergent-divergent) nozzle at a altitude of 15,000m. I am stuck on how to calculate the areas so that at the throat of the nozzle Mach number equals to one. The ...
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What is the diameter of each stage of the PW800 engine compressor and turbine?
I am an Aerospace Engineering student working to analyze P&WC's PW800 engine family--specifically, the PW814GA, for a project and we need to know some hard-to-find data.
Does anyone knows where I ...
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54
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What is the engine shell temperature?
What are the highest temperature locations in the outer shell on an aircraft engine? Particularly, modern turbofans like the Trent 900 for example. I'm interested in the temperature constraints of ...
- 41
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61
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Are throttleable rocket engines the less efficient the lower the power setting?
Are throttleable rocket engines less efficient the lower the power setting? Logically that would lead to lower pressures in combustion chamber and so lower thermodynamic efficiency. Or is it remedied ...
- 2,484
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148
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What gas turbines have the following configuration?
Is there any jet engines--with published data on the dimension of the turbines and compressors--that are of the configuration of 2 Low Pressure compressor, 8 High Pressure compressor, 2 High Pressure ...
- 313