Talk:Centrifugal compressor

Image
That image is HUGE. dq 21:07, 15 February 2006 (UTC)


 * This page needs an illustration. Telling from the history, it looks like it used to have one, but it was copyrighted and thus removed. It needs something like this to get the real feel of what's going on. Novous 15:40, 14 April 2006 (UTC)

Remove discussion of "centrifugal force"
"centrifugal not a real word"? It has a real wikipedia entry ... (which quite clearly explains about reactive and fictitious forces, and the rotating frames of reference). Can this aside be deleted? Daniel Barlow 09:26, 24 April 2006 (UTC)


 * I agree, that paranthetical statement should be removed as it's not relevant to compressors. I'll take it out. (Besides, centrifugal forces do exist just as much as imaginary numbers exist...) dq 14:43, 24 April 2006 (UTC)

Tip speed
"Tip speeds of centrifugal compressors" was changed in a previous revision to "top speeds". I'm not an expert in the subject, but I believe "tip speed" was the correct phrase, not a typo. Does anyone who is wish to comment/revert? Daniel Barlow 13:28, 12 December 2006 (UTC)


 * The phrase "Tip speed" refers to the rotational speed of the vanes on the outside of the compressor impeller, i.e., the angular speed of the vane tips the furthest from the compressor shaft. This is important as the fastest-moving part of the compressor should not reach the speed of sound - Mach 1.0 as not only does efficiency drop markedly, but also noise is greatly increased. This applies to aircraft propellers and jet engine Axial compressors as well.

FYI and for Discussion only
Agree:
 * 1) Centrifugal compressors are used throughout industry because they have fewer rubbing parts, are relatively energy efficient, and give higher airflow than a similarly sized reciprocating/positive-displacement compressor.
 * 2) Centrifugal fan/blowers are more suited to continuous-duty applications such as ventilation fans, air movers, cooling units, and other uses that require high volume but fairly low pressures. Multi-stage centrifugal compressors often achieve discharge pressures of 8,000 to 10,000 psi injecting nitrogen into oil fields to increase oil production

Disagreements: --Mkoronowski 18:49, 25 January 2007 (UTC)
 * 1) Professionally, I know of no one in the HVAC industry that would ever refer to a squirrel cage blower/fan as a compressor. The squirrel cage impeller discharge flow within the scroll is not circumferentially uniform.
 * 2) Centrifugal compressors DO NOT operate by using the centrifugal force applied to an air mass to achieve compression. Centrifugal is a misnomer.
 * 3) It is almost irrelevant that centrifugal blowers can operate in reverse and act as a turbine.
 * 4) Also, pipeline compressors are not really referred to as jets, most often they are driven by gas-turbines, thus use of the term jet.

I propose the following replacement of the current text
'''This is the current text to be I propose to replace: A centrifugal compressor, also called a radial blower, squirrel cage, or squirrel wheel compressor, consists of a cylindrical assembly of compressor blades mounted on an axle. The compressor operates by using the centrifugal force applied to an air mass to achieve compression. Centrifugal compressors are used throughout industry because they have few moving parts, are very energy efficient, and give higher airflow than a similarly sized reciprocating compressor. Their primary drawback is that they cannot achieve the high compression ratio of reciprocating compressors without multiple stages. Centrifugal compressors are more suited to continuous-duty applications such as ventilation fans, air movers, cooling units, and other uses that require high volume but fairly low pressures. While technically centrifugal blowers can operate in reverse, due to blade design and other factors their efficiency is greatly reduced. When centrifugal blowers are used in pipelines they are sometimes called jets.

This is the proposed text to replace the above text: Centrifugal compressors, (sometimes referred to as radial compressors) are a special class of radial-flow work-absorbing turbomachinery (ref Turbomachinery, Euler) that include pumps, fans, blowers and compressors. The earliest forms of these dynamic-devices were pumps, fans and blowers. What differentiates these devices from compressors is that the working fluid can be considered incompressible thus permitting accurate analysis through Bernoulli’s Energy equation (ref Daniel Bernoulli). In contrast, modern centrifugal compressor analysis must deal with compressible flow.

For purposes of definition, centrifugal compressors often have density increases greater than 5-percent. Also, they often experience relative fluid velocities above Mach 0.3 when the working is air or nitrogen (ref Ernst Mach, Mach Number). In contrast fans or blowers are often considered to have density increases of less than 5-perent and peak relative fluid velocities below Mach 0.3

In an idealized sense, the dynamic compressor achieves a pressure rise by adding kinetic-energy/velocity to a continuous flow of fluid through the rotor or impeller. This kinetic energy is then converted to an increase in static pressure by slowing the flow through a diffuser [2]. --Mkoronowski 10:25, 30 January 2007 (UTC)

Mkoronowski, please read this help on how to use this page
You have greatly improved this article on centrifugal compressors and I know that you are new to Wikipedia. But I think you need help in learning how to use a Discussion page such as this one.

First of all, always sign your discussion comments. And new comments always go beneath the older comments (not above them).

Also, it is not allowed to delete any discussion comments from a discussion page, as you did. I will try to straighten that out and replace the comments you deleted when I get time to do so.

Please read the boxed instructions at the very top of this page carefully. Those instructions explain how to automatically sign and date your discussions and how to indent your responses to someone else's discussion. Again, please study the above instructions.

Finally, you do not need to use HTML to get double spacing. Just skip a line in your text and Wikipedia will automatically give you a double space. And don't use HTML to list items ... instead, just use asterisks ( * } as I did for one of your above discussions. They will automatically give you a bulleted list. HTML is frowned upon in Wikipedia, so try to learn the Wiki markup language ... it is quite simple.

I hope this helps you and welcome to Wikipedia. - mbeychok 06:54, 31 January 2007 (UTC)

Many many thanks
I want to thank everyone that helped "wikify" my update of the discussion. I know it is obvious that I am new to wikipedia and will certainly need help in the future. My rush to improve the entry was due in part to the number of unintentional misrepresentations that I have seen for too many months.

Again, thank you very much.

I will try my best to meet Wiki's standards. I must apologize for any deletions. I consider that a serious error and am very embarrased.

If I could ask, is there an advisory board where professionals like yourself could spend some one-on-one email time with someone like me to get me up the learning curve? I would have been a lot less dangerous.

Why are your comments to me not being forwarded to my email as i hoped I had requested? Mkoronowski 18:29, 31 January 2007 (UTC)


 * Your question about an advisory board to help you is the same question I asked when I was new to Wikipedia. No, regretfully there is no such board.


 * I addressed my above comments to you hopefully to be helpful. If you need further help, you can always contact me on my user page at User talk:mbeychok and I will try to help ... if I have the time. You can also contact me at my email: mbeychok@cox.net and I will try to respond when I have the time. Discussion responses are most usually placed here for everyone to see and for others to learn from the discussions as well. Private e-mail should only be used when confidentiality is a concern.


 * Looking at the Edit page of articles (and the Edit page of Discussion pages) is one of the best ways to learn how Wikedia does things.


 * I repeat what I wrote above: Please read the above instruction on how to use this Discussion page. When you want to respond to someone else's comment, you simply indent using : or :: or ::: as the case may be. You do not put a heading (like == Many thanks ==) on your response. Look at the Edit page for this discussion to see how I formatted my response to you.


 * When you want to discuss a new point, you click on tab marked + at the top of this page and that will give you a form with a space for the subject and a space for discussion of your new point. When you finish, that form will automatically format your heading (like ==Subject==) and automatically place your discussion beneath the previous discussions.


 * It is best to use capital letters to start sentences. Best regards,- mbeychok 19:31, 31 January 2007 (UTC)

Cleanup
Someone who know knows this subject well should clean up this article. It appears to have been partially edited many times, and there are many unfinished fragments, etc. I cannot as I don't know much about this subject so I wouldn't know which fragments to complete, which to delete, etc. I'll add a CLEANUP tag. Srajan01 (talk) 04:26, 10 June 2008 (UTC)

What needs to be included???
Mkoronowski (talk) 23:49, 5 November 2009 (UTC) What do you think is missing?

If one looks at the history of turbo machinery in mankind, one can make a very logical argument that compressors, pumps and turbines are responsible for mankind’s ability to successfully live in modern cities. i make this point to suggest that this topic, while obscure is very important.

Let us put this into perspective, no turbo machinery equals No large pharmaceutical manufacturing No refined petroleum, gasoline, plastics No natural gas distribution No large air conditioned buildings No commercialized nor industrialized southern usa No jet airlines And this is just the tip of the iceberg.

I do think I see room to discuss the operation and design theory broken into two overall topics as follows.

(I)	Thermodynamic, aerodynamic, hydrodynamic fundamentals and theory.

(II)	Mechanical design, strength of materials, vibration, noise, heat transfer fundamentals and theory.

I think I would exclude manufacturing technologies simply because of the wide range of processes and materials. I also think we must be careful to avoid design theory as there are too many seemingly opposing points of view as a result of commercial motives.

For those that are interested, please comment as soon as convenient.

Mkoronowski (talk) 23:49, 5 November 2009 (UTC)

Density increase
Quote: "For purposes of definition, centrifugal compressors often have density increases greater than 5 percent". What does this mean? Does it mean compressing the gas by 5% (a very small compression ratio) or to 5% of its original volume (a very large compression ratio)? Biscuittin (talk) 16:56, 29 March 2010 (UTC)
 * if you look under either aerodynamics, fluid dynamics or ideal gas you might be able to find out that density in units of mas per volume and is calculated for a gas by the ratio of pressure divided by tempereture time the gas constant. all i was trying to say is that when the machine increases the pressure (and temperature) so that the density increases 5percent it is likely the dynamics of the machine may qualify it to be called a compressor. do you remember dalton's gas law from high school chemistry or physics? Mkoronowski (talk) 23:11, 21 April 2011 (UTC)

Add graphics to explain article content
Mkoronowski (talk) 04:08, 16 April 2011 (UTC)

how do i upload a graphic. this is a test

Reynolds Coefficient:
 * $$ \Pi_5 = \left(\frac{\rho N D^2}{\mu}\right)$$

Specific Speed Coefficient:
 * $$ \left(\frac{\Pi_1^{ 0.5}}{\Pi_2^{ 0.75}}\right) = \left(\frac{N D^{0.5}}{(g H)^{0.75}}\right)$$

Corrected Mass Flow Coefficient:
 * $$ (\Pi_1\Pi_4) = \left(\frac{m Rt^{0.5}}{p D}\right)$$

Mkoronowski (talk) 04:08, 16 April 2011 (UTC)
 * }

the following discussion will be duplicated in as many turbomachinery entries as possible.
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) 22:19, 30 April 2011 (UTC)


 * I don't think it will be productive to duplicate this is a bunch of places. You can remove the tag if you think it's no longer needed, but if you're asking for our help to finish it off, it's probably best to leave it for now.  On the other articles, it will be good to link this article for the unifying theory.  There's no real problem with end-user and application colloquialisms, as long as they're supported by reliable sources, but correcting errors is certainly a great goal.  See WP:BRD; go ahead and be bold, but discuss your plan if you get pushback.  Dicklyon (talk) 22:26, 30 April 2011 (UTC)
 * how do you link them? Mkoronowski (talk) 22:35, 30 April 2011 (UTC)
 * Maybe a section note like this:


 * or:


 * Dicklyon (talk) 04:27, 1 May 2011 (UTC)
 * thankyou ! I respect your opinion. please be crtical, what is your opinion of centrifugal compressor? thxs again, Mkoronowski (talk) 19:10, 1 May 2011 (UTC)

design methodology & coordinate systems
Two sections that potentially could be incorporated into centrifugal compressor are: Design methodology and Coordinate systems Within design methodology is important to understand that design and analysis are opposites. In fact design is sometimes referred to as inverse analysis. The general process is as follows: Design begets Design analysis begets Testing begets Testing analysis begets New design begets New design analysis and so on and so on. The end result of this four step process is that it continues on several different layers. One-dimensional, two-dimensional, and three-dimensional. it is at specific critical junctures that the Aero-thermodynamic analysis waits while mechanical/stress/migration analysis occur. Even to the most experience this is one nice bowl of spaghetti. this is the point where neutral point of view needs to stop discussion. The devil is in the details of the one-dimensional and two-dimensional and three-dimensional analysis.

Within coordinate systems there is virtually four points of view. There is the Cartesian coordinate system looking downstream which is seldom used in anything other than CFD. Then there is the Cartesian coordinate system looking upstream which is again seldom used in anything other than CFD. then there are the polar coordinate systems which either look upstream or downstream. in all cases a right hand rule is applied to establish the positive sense of rotation(which is sometimes the opposite of the right hand rule).

At this point in time I don't see any value in discussing design methodology on anything other than the coarsest level for the very few that might be interested.

Additionally I don't see any value in all in discussing coordinate systems. Those that need to establish coordinate system already have a preferred favorite and those we don't need a coordinate system probably have no interest.

does anybody have any comments or thoughts that they would like to share on this topic? Martin mkoronowski Mkoronowski (talk) 02:18, 1 May 2011 (UTC)


 * I don't want to sound rude, but this reads as if it someone had fed some engineering jargon into a random sentence generator. The article has the same problem. I'm sure the maths are fine - you've been an engineer for 35 years - but it's often borderline-incomprehensible, with long unexplained lists of names and unintroduced concepts. As if it was the notes for a slide presentation given half-way though an engineering degree course. You have a lot of knowledge inside that head of yours, if only there was a way to extract it in a form that other people could understand. -Ashley Pomeroy (talk) 18:29, 30 December 2015 (UTC)

Speed Parameter in Dimensional analysis Section
Should the Speed parameter have units s^-1 ie. Rad/s for the rotational speed of the impeller, rather than linear speed, where the radian is itself dimensionless.

Using m/s for the "Speed" means that the five dimensionless parameters shown in the article are in fact not dimensionless. — Preceding unsigned comment added by 89.101.96.81 (talk) 21:19, 1 August 2011 (UTC)


 * thankyou for your questions. As you point out, Speed has several definitions in turbo-machinery. the speed (often denoted "U") typically refers to the rotor's discharge rim velocity. popular units for this are meters per second ( m/s = m*s^-1). In contrast, rotational speeds (often denoted "N") referring to the shaft speed use units like revolutions per minute (rpm) or radians per second (also denoted "Ω" omega). I understand radians are considered dimensionless. Having been educated in SI units and then worked primarily with USA's English units, I have often made the mistake of quickly combining English units to calculate the wrong dimensionless value as a result of carelessly not checking the units used. The obvious lesson being one must always check units when calculating a dimensionless parameter. However, there is a problem, some segments of the turbo-machinery industry have chosen to use dimensioned dimensionless parameters. For example a dimensionless specific speed calculated by NASA may have a value of 1 while the same specific speed used by company XYZ has a dimensioned value of 129.3.


 * Answer part1: I quickly reviewed the article and noted m/s were noted. Do wiki standards require basic notation? or is standard algebraic notation acceptable? Answer part2: the resultant units of a dimensionless parameter must be validated. Even the parameters need to be validated, as is the case of differentiating between polytropic and isentropic thermodynamic processes. Mkoronowski (talk) 00:11, 17 September 2011 (UTC)

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Jargon or terminology
Reviewing “centrifugal compressors” revision history, I find editors “simplifying jargon”. Articles throughout Wikipedia, the arts, mathematics, science, and applied sciences are filled with jargon (terminology) specific to that field. I can give a great example; How often have you met individuals needing to understand the differences between surge and stall? I often read Wikipedia articles specifically looking for the correct terminology.

The field of centrifugal compressors is an advanced applied science and naturally filled with scientific terminology. This article herein Wikipedia appears to be written in two parts.

The first introduces the topic of centrifugal compressors by describing, their key components, the variety of components, where and how compressors are used, how they are similar and different, and how they are similar and different from other turbomachinery. Added to this is a summary of their history and development and a philosophical overview. Casual readers should find this interesting and filled with a minimum of jargon.

Hopefully understood is the vast variety of centrifugal compressors mostly due to the vast range of applications.

The second part of this article is more detailed. It introduces the applied mathematical foundation used in their aero-thermo design and development. I expect readers in these sections will be looking for terminology to research centrifugal compressors in more depth. The reader may need to write a paper, attend a meeting, have a technical discussion, find a manufacturer, order parts, go to an interview, perform a Google search.

I need to ask, where is the line between too much and too little jargon?

Thank you for helping!

Mkoronowski (talk) 04:40, 5 December 2021 (UTC)

Citation Footnotes
The footnotes of many citations are textbooks covering a full scientific discussion of centrifugal compressors. Rather than assign a citation to a specific sentence is there any benefit to assigning the citations with the topic's title? For example, Most modern high-efficiency impellers use "backsweep" in the blade shape.[2][3][4], is the only sentence supported with a citation. Thus, none of the other statements supported. Actually, [2][3][4] support the entirety of (1.2)"impeller". Please, what method does Wikipedia prefer to support this kind of material?

Thank you, Mkoronowski (talk) 02:11, 6 December 2021 (UTC)