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Engine combinations

  1. Aug 28, 2006 #1
    Hi all,

    I am writing a course for budding engineers. I have been a marine engineer for long. While compiling my course I seem to have hit a roadblock that has made me aware of my ignorance in spite of my experience. I would like some help on this from anyone.
    I have classified diesel engines as follow:
    there are 5 major categories:

    1. Operating feature
    2. Cylinder arrangement
    3. Piston connection
    4. Piston action
    5. Speed

    the sub-categories for each of the above will be:
    1a. 2-stroke
    1b. 4-stroke

    2a. Horizontal
    2b. Vertical
    2c. Inline
    2d. Vee
    2e. Radial

    3a. Trunk type
    3b. Crosshead type

    4a. single-acting
    4b. double-acting

    5a. Slow speed
    5b. Medium speed
    5c. High speed

    From the above, what are the possible configurations? I mean, can we have a 1a, 2a, 3a, 4a, 5a engine? and likewise. I would like to present it to my students with examples. Can anybody help?
    Thanx
    Abid
     
  2. jcsd
  3. Aug 29, 2006 #2

    Danger

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    Unfortunately, I'm not a Diesel guy. If the subject was gasoline motors, or if I wasn't so burned out, I'd take a shot at it now. Since it's so interesting, though, I'll dive in after some sleep. Good topic.
     
  4. Aug 29, 2006 #3
    normal, supercharged , turbo charged
     
  5. Aug 29, 2006 #4

    brewnog

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    Off the top of my head:

    - Any charge cooling
    - Direct injection versus indirect injection
    - Type of fuel injection equipment
    - Type of cycle the engine operates on
    - Type of fuel the engine uses

    There are many other factors which you could classify Diesel engines by.

    Also, there's nothing to stop an in-line engine being horizontal, or a vee being vertical, if you see what I mean for your '2' category. I don't see the benefit in using a numbering system for the classification either.
     
    Last edited: Aug 29, 2006
  6. Aug 29, 2006 #5

    brewnog

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    Oh, and if you're wanting to be accurate with classifications, then turbocharging is just one type of supercharging.
     
  7. Aug 30, 2006 #6

    Mech_Engineer

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    Perhaps

    xa. naturally aspirated
    xb. forced induction

    I also think direct/indirect injection should be mentioned.
     
  8. Aug 31, 2006 #7
    Thankyou Danger,
    Do hope to hear from you after you have had your nap.

    Well brewnog, mech-engineer and ray b, thank you for responding. I could add 'Type of air induction' as a major category that could include a-normal aspiration, b-supercharged, c-turbocharged as sub-categories.
    However my idea is to create a combination box into which one could drop one sub-category from each major category and see whether the end result is a workable engine, if so are there any examples?
    Pls scout around. Would be helpful for the students to recognise the classification of engines when they could do it themselves.
     
  9. Aug 31, 2006 #8

    Danger

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    Well, unfortunately I haven't managed much sleep since my first response because the wife is ill (not anything for my friends to worry about, but she moves a lot in her sleep, which wakes me up). One topic that comes to mind is valve configuration. Again, I don't know much about diesels, but is there a possibility that a rotary valve such as in a gasoline 2-stroke could be used? Or a cylindrical (like a ball-cock) rotating one? Maybe the actuator system (overhead cam, push-rod, hydraulic, etc.)?
    What about headers vs. non-tuned exhaust? Windage trays? Porting and polishing heads? Electronic vs. mechanical fuel management?
    Just babbling. :redface:
     
  10. Sep 1, 2006 #9
    Thanx Danger,
    Sleep deprivation is the norm nowadays, so I think you better get used to it. Your suggestions are taken, but they still don't address my original query.
     
  11. Sep 1, 2006 #10

    brewnog

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    Then I don't understand the query.

    Different applications will require different parameters, but there is no definitive optimum engine type for a given application. I don't understand the purpose of your drop-down box idea, you can theoretically produce a working engine with a combination of any of the parameters we've discussed. Whether that engine is "workable" or not is a subjective decision based upon a huge number of factors (application, geographical location, duty cycle, packaging, fuel availability and cost, politics, cost of components, required life....).
     
  12. Sep 1, 2006 #11
    Let me make it clearer.
    If I were to choose, say the following combination:
    1a, 2e, 3b, 4b, 5c from my list, which would translate as
    2-stroke, radial, crosshead type, double-acting, high speed engine.
    Would such an engine practically exist? And are there any examples of application? (I have not included type of air induction here).
     
  13. Sep 1, 2006 #12

    Danger

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    Okay, there are a couple of impossibilities raised by that. For instance, you can't have a radial with less than 3 cylinders. And depending upon your definition of 'slow speed', that would rule out a 2-stroke (at least in a gasoline motor). If 'double-acting' means the same thing in Deisels as it does in hydraulics, then I dont' even know how the hell it could be achieved. And I have no idea what 'cross-head' or 'trunk type' means. :redface:
     
  14. Sep 3, 2006 #13

    brewnog

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    Do you want us to go through every combination raised by your arbitrary classification system and say whether there's a real life example of it?
     
  15. Sep 3, 2006 #14

    Danger

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    I just thought of something here. I'm way too lazy to try figuring it out myself, so I'm going to throw it out there and see what happens.
    Is it possible that a Diesel engine could be configured as a Wankel type?
     
  16. Sep 3, 2006 #15

    brewnog

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    Last edited: Sep 3, 2006
  17. Sep 3, 2006 #16

    Danger

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    Thanks, Brewski. I think that I must be missing something here, though. Those references seemed to be about otherwise conventional gas engines burning Diesel fuel. The one that probably answered my concern was the first link in the last post, where they mention the low compression of a Wankel. I just couldn't quite figure out how a rotary could develop a high enough compression ratio to achieve auto-ignition... which to me is what it means to be Diesel.
     
  18. Sep 3, 2006 #17
    Diesel engine cooling configuration

    Should cooling be a consideration as well? (Air cooled & water cooled)
     
  19. Sep 3, 2006 #18

    Danger

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    That's always a consideration. I've never seen an air-cooled Diesel, but there's no reason that it can't be done.
     
  20. Sep 3, 2006 #19
    Yup, that's the whole idea. I want the student to go through every combination raised by my arbitrary classification system and see whether there's a real life example. The combinations may work out to a long list, but i am sure it will enlighten the student.
     
  21. Sep 4, 2006 #20

    brewnog

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    And you want us to make the list?

    What level student are you designing this for?

    There isn't a person in the world (let alone on this forum) who will know that there definitely isn't an example of, say, an air cooled, water charge cooled, supercharged, 2 stroke CI engine running on heavy oil on a Miller cycle somewhere in the world.

    Perhaps it would be of benefit to you to look at some brochures of commercially available engines. Go and look at websites for Cummins, Cat, Perkins, MAN, Scania, Volvo, Deutz etc and see what you can find.
     
    Last edited: Sep 4, 2006
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