Talk:Axial compressor

"Since compression ratio is strongly related to fuel economy, this eightfold increase in compression ratio really does result in an eightfold increase in fuel economy for any given amount of power..." um, right..

Actually all types output which we get after compressor (turbine etc.) can be directly effected by changing mass flow rate thats why we try to increase massflow rate by increasing compression.

why there are always more number of stages in compressor as compared to turbine if we specifically talk about power plants?

eightfold increase
I've removed the "eightfold increase" stuff, as it is clearly wrong. 40:1 is not 10 times more efficient than 4:1, or early jets would not have had enough fuel to take off. Current jets are what... 25% efficient? Raising their compression to 400:1 will not make themn 250% efficient, I can assure you. I suspect efficiency is proportional to (1 - 1/compression), but I don't know nor can prove this... does someone know how compression factors into the theoretical carnot efficiency at a given temperature? Or does increasing compression mostly just increase power or decrease frontal area? 82.69.54.182 10:53, 6 September 2006 (UTC)

Potential Source?
I came across the following link, is it the source of this information or a copy of this article?

http://www.scribd.com/doc/15185649/Turbofan-Engine —Preceding unsigned comment added by RankM (talk • contribs) 23:52, 29 November 2010 (UTC)

Axial compressor
Axial compressors should not be listed inside chemical and bio engineering. It should be included in a general turbomachinery category that includes all dynamic axisymmetric turbomachinery. This includes both centrifugal compressors and centrifugal pumps. All of these devices operate on the same fundamental physical principles. I do not understand also few experts have separated all of these different articles. Mkoronowski (talk) 07:08, 21 April 2011 (UTC)

Axial compressors
There seems to me to be three problems with this article—
 * First is that the article starts by using a number of complex theorems to explain how an axial compressor works, rather than the simple idea of converging and diverging ducts and how they exchange velocity, pressure and temperature—in a stationary and in a rotating environment if necessary.


 * Second is that someone wants to say that axial and centrifugal compressors, and their intermediate combinations, are different from each other because one exhausts axially and the other radially! If you look carefully at any combination you'll see that both exhaust radially, or at least partially so. One just cannot apply velocity to a working fluid without centrifugal force acting on it. Centrifugal movement of the fluid is radial to the operating machine's rotation. And try not to denigrate my statement by saying that the article uses the word principally. In large diameter engines the radial component is (can be) large in either type, in small diameter engines it is relatively small. In large and small engines the radial motion if the working fluid is important if you're a designer, but not so important if you're writing for the ordinary person.


 * Touting an axial compressor's flow advantages and not mentioning that it is susceptible to serious damage by solid particles (objects) in the entrained flow is a serious deficiency.

Let us see the beginning of the article tell the story in the simplest possible, plain, terms and wait to get complicated later, keeping in mind that everyone is not an aerodynamicist nor a dynamic mathematician. Try to keep the initial explanation within the bounds of a normal reader not yet at PhD level. Lin (talk) 12:08, 2 August 2012 (UTC)


 * < One just cannot apply velocity to a working fluid without centrifugal force acting on it > No. The principle of the axial compressor requires only pairs of infinitely long 2-D cascades in relative motion. (You mention simplest possible, plain, terms.) The rotation of finite rows bent round into a circular cascade is purely for mechanical convenience 86.152.112.92 (talk) 22:50, 14 October 2012 (UTC)

Working
In the diagram titled Diagram of an axial flow compressor I'm unhappy with it showing the inlet guide vanes directing the flow in the direction of rotor stage motion. It seems to me that shows the inlet guide vanes for a turbine section. In an axial compressor the function of inlet guide vanes is to condition the flow so that the driven (rotor) blades can impart the most energy to the fluid. I haven't got my text books here right now, but I'm seriously doubting the authenticity of the diagram. Lin (talk) 12:42, 2 August 2012 (UTC)
 * No, it's right! Brain-fade. Lin (talk) 08:36, 3 August 2012 (UTC)

in need of advice and help!
Under what conditions and the following statement be removed from centrifugal compressor? "Cleanup|date=June 2008" centrifugal compressor is currently in a semi-complete state. It has not been proofread and has not been verified to standard that I would like to apply. I would like to ask for everyone's help to please review the article and make comments on the discussion page. I really will attempt to incorporate all of your improvements in a rigorous and consistent fashion. it is important that you are happy the way your issues are addressed. It is currently missing a section on "design methodology" that I would like to research and discuss before I complete. There are significantly different points of view that I would like to try to unify. the section on design methodology is not original work and will be properly referenced. All turbomachinery is unified by fundamental physics in the applied mathematics use in their design and analysis. That is why the term turbomachinery can be used as an umbrella topic. Dozens of academic textbooks attest to the above statement. Other than one other turbomachinery entry I have not been happy with the technical and scientific accuracy of any other encyclopedic entries. Most of these entries have been negatively impact by end-user and application colloquialisms. I will slowly, starting with centrifugal pumps and centrifugal fans try to correct various errors in statements. Unless I am asked I will not make any significant changes to the outlines of these encyclopedic articles. thank you for everyone's help martin koronowski, Mkoronowski (talk) 22:22, 30 April 2011 (UTC)

See also section(s)?
A top-link to Centrifugal compressor has been added. This should really go into a "see also" section. I was thinking of copying the "Turbomachinery" and "See also" sections from Centrifugal compressor (with an appropriate edit or two), as the contents of those are as relevant here as they are there, but they seem a bit over done. Comments? Rwessel (talk) 16:28, 2 May 2011 (UTC)

Surge
< the remaining hot air in the rear of the engine allows the turbine to speed up the whole engine dramatically >

I don't have sources to hand, but I find the statement above unbelievable. (If the compressor ceases to compress, the amount of 'remaining hot air' is exhausted in milliseconds. What kills blades is the vibration engendered by flow reversal). 86.3.108.41 (talk) 16:19, 1 October 2011 (UTC)

Removed every PAGE instances here
Well before my edit nearly every link here goes here: http://en.wikipedia.org/wiki/PAGE because all links in this page started with PAGE|, so I copied all of the text to notepad++ and used its search and replace function to remove all of that PAGE|, making some of the link red — Preceding unsigned comment added by 118.136.5.235 (talk) 13:22, 23 May 2013 (UTC)

Fluids and gasses.
Why does the article consistently refer to the axial compressor as working with "gasses"? Gasses are fluids, and that is what axial compressors work with. The only mention of fluids is in the opening sentences (I added a second one to the first sentence to make it "gasses and fluids", which doesn't really make sense but might make it clearer to those who aren't used to these terms. However, I think that the technical term is "working fluid", or am I messed up? I know that axial compressors are most often used to compress gasses, that doesn't make it the correct terminology..45Colt 10:09, 8 January 2015 (UTC)
 * If nothing else compressors don't generally work at all with liquids. In any event "gasses and/or fluids" doesn't make much sense, better would be something like "gasses (fluids)".  Rwessel (talk) 10:52, 8 January 2015 (UTC)

Please clarify Flow coefficient, valve, pipe

 * The article uses but does not seem to define Flow coefficient
 * In the Surge cycle section it mentions valve and pipe without explaining what they are in this context. Is the 'pipe' what the compressor exhausts into ? Would an aircraft jet engine compressor have a 'valve' ? Where (apart from in the fuel line) ? - Rod57 (talk) 10:27, 27 April 2018 (UTC)
 * Please see edit for clarification. In answer to your question oompressors do have valves, called bleed valves or blow-off/bleed-off valves (known as BOVs) at different places part-way through the compressor to stop the airflow stalling and surging (cause of dramatic photos showing flames coming out the front and back of the engine). Some valves are needed just to get the engine started to its idle speed, without which the front blades stall (rotating stall) and the engine won't accelerate to idle or take much too long (burnt turbine). Other valves (known as handling bleed), when opened further along the compressor enable it to speed up fast without surging. Other things which deal with stalling and surging are variable-angle vanes, 2 or 3 separately rotating compressors. Some engines have all three because the root cause of stalling and surging is asking a compressor to produce more pressure than its capable of without them, ie more than about 5x what is coming in. 5x was surpassed around about 1950.


 * The rig-test 'pipe' goes from the exit of the compressor to the adjustable test valve.


 * Flow coefficient?- From what I can see this is used for plotting performance of a single stage, rather than the whole compressor so needs deleting or clarifying.Pieter1963 (talk) 00:16, 29 April 2018 (UTC)


 * I have messed up a picture file. Not sure what to do apart from deleting it as uncited own work. I cannot find anything which supports it, ie shows losses on a pr flow plot.Pieter1963 (talk) 03:42, 29 April 2018 (UTC)

Jet engines are aerospace
"Due to high performance, high reliability and flexible operation during the flight envelope, they are also used in aerospace engines" Okay, not sure what that means. Jet engines are already listed earlier in the paragraph, and aerospace includes all engines designed for use in the atmosphere or space. I am not sure if the editor who wrote this thinks aerospace means "space ship engines", if they are referring to modern launch vehicles like those used by Virgin (which are just normal jet engines), or if they are thinking of turbopumps used in liquid fueled rockets. I believe those are typically axial pumps, but I am not sure. I cannot clarify the statement because I can't tell what they were trying to say.

64.223.159.140 (talk) 11:37, 22 April 2021 (UTC)

Cenrtifugals in helicopters?
I removed this sentence because it seems nonsensical or badly outdated: " For this reason they remain a major solution for helicopter engines, where the compressor lies flat and can be built to any needed size without upsetting the streamlining to any great degree." Since when was streamlining a major issue for helicopters? It makes the packaging somewhat easier, for sure, but thats about all.

64.223.159.140 (talk) 13:07, 22 April 2021 (UTC)

Clarity of Source
The Boyce reference (2) is unclear as it just links to BoyceConsultancy.com. The actual source is Table 1, Ch. 2 of the Gas Turbine Handbook, authored by Boyce. Could this be elucidated better? HydrogenRules (talk) 14:22, 17 October 2022 (UTC)