Engine combinations

[abidansari]

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

[Danger]

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.

[ray b]

normal, supercharged , turbo charged

[brewnog]

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.

[brewnog]

Oh, and if you're wanting to be accurate with classifications, then turbocharging is just one type of supercharging.

[Mech_Engineer]

Oh, and if you're wanting to be accurate with classifications, then turbocharging is just one type of supercharging.

Perhaps

xa. naturally aspirated
xb. forced induction

I also think direct/indirect injection should be mentioned.

[abidansari]

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.

[Danger]

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:

[abidansari]

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.

[brewnog]

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....).

[abidansari]

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).

[Danger]

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:

[brewnog]

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?

[Danger]

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?

[brewnog]

Yeah it's possible, but there are engineering issues. There was a thread about it a while back, I'll see if i can find it.


EDIT: http://www.physicsforums.com/showthread.php?t=110109&page=2&highlight=diesel+wankel

The last post is probably the most useful.

[Danger]

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.

[AO eye 5]

Should cooling be a consideration as well? (Air cooled & water cooled)

[Danger]

That's always a consideration. I've never seen an air-cooled Diesel, but there's no reason that it can't be done.

[abidansari]

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.

[brewnog]

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.


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.

[ray b]

That's always a consideration. I've never seen an air-cooled Diesel, but there's no reason that it can't be done.

semi common on one and two cyl pump and gen sets

[abidansari]

Alright, I think I seem to have hit the same roadblock again. When I started on the idea, I was overwhelmed by the sheer range and permutation/combination the mixing of categories would produce. As I have been cautioned rightly, I think I need to take a different approach. Perhaps, I could make a list of engine configs and ask you all for a suitable example. Maybe that way I could possible get to where i am headed.

[brewnog]

Perhaps, I could make a list of engine configs and ask you all for a suitable example. Maybe that way I could possible get to where i am headed.

Sounds like a much better plan, but remember our examples won't be exhaustive.

What level of education are you aiming this at?

[abidansari]

A single example for each would do.
This is targetted at students who are at the beginning of their engineering studies.

[Danger]

Okay then, I'll start off with the one that's most common in my area (farm country). A lot of folks around here are running Diesel pick-up trucks, usually crew-cab or club-cab long-box duallies for hauling heavy trailers. The engines are:
V-8 or V-6
Turbocharged
Intercooled
Direct injection
Low-Medium speed (idle-3,500 rpm or so)

[brewnog]

Ok.

The engines I work on are:

In-line 6 and 8, and Vee 12 and 16 cylinder
Turbocharged
Air/air and water/air charge cooled
Direct injection
Medium speed (1200-1800rpm)
Heavy duty
Diesel fuelled

[Danger]

Oops! Thanks again, Brewski. I forgot about the cooling. The rigs that I referred to are cooled by a conventional water/air radiator using standard antifreeze.

[brewnog]

Looks like I forgot about cooling too. All mine are water cooled, but some use a remote radiator or heat exchanger.

[brewnog]

The JCB world land speed record breaking car's engines:


Four cylinder
Four valves-per-cylinder
In-line
Twin stage turbocharging with aftercooling
Common rail direct injection with twin pumps

The engine is cooled with blocks of ice.




Incidentally, this vehicle still managed 11mpg!

[brewnog]

Wartsila-Sulzer RTA96-C - marine Diesel engine:


14 cylinders in-line
38" bore, 98" stroke
Turbocharged, aftercooled
25,480 litre capacity
Crosshead type
2 stroke
Uses heavy fuel

The engine produces 108,920 bhp at 5,608,312lb ft torque.

[ray b]

intercooled I understand [compressed air heat reduction]
but what is after cooling, how does it work,
what are the power gain or other effects

[brewnog]

Aftercooling is probably what you think intercooling is. Cooling of the charge air following compression. The effect is increasing the density of the charge air. Resultant effects can be increased power density and torque (greater expansion of air under combustion). In the past 10 years with on-highway, and in recent and coming years in off-highway, aftercooling will be increasingly used on Diesel products in order to lower peak in-cylinder temperatures for NOx control.

[abidansari]

Ok guys, here's how it works
I need to know if the following configurations are possible. If so, please tell me any one application where it it used.

1. A 2-stroke-Inline-Horizontal-Trunk type-Single-acting-Air-cooled-Slow speed-Normally aspirated engine???

2. A 2-stroke-Inline-Horizontal-Trunk type-Single-acting-Air-cooled-Slow speed-Supercharged engine???

3. A 2-stroke-Inline-Horizontal-Trunk type-Single-acting-Air-cooled-Slow speed-Turbocharged engine???

[ray b]

can you have a 2 stroke with out a blower in a diesel of any real size
all the GMC 2 strokes are blown

the only unblown air cooled 2 strokes I HAVE SEEN
were small bike add on motors about 50cc and 2 hp

[abidansari]

So can I conclude that a normally aspirated engine among the above configurations cannot exist?

[brewnog]

No abidansari, this was my point. You most certainly not conclude that your mentioned configurations don't exist. It's entirely possible that there's such an engine somewhere in the world that none of us know about, hence why ray b said "I HAVE SEEN".

When you say air-cooled, do you mean jacket water cooling or charge air cooling?

[abidansari]

I meant Jacket water cooling.
And yes thanx for reminding me. It could be possible that any engine configuration could exist for some particular application. It is just that I wanted to show the most popular or the most used types.
And also considering the fact that only you & ray b are giving some thoughtful answers here, maybe I should try some other forums. Do you know of any where the participation is more?

[brewnog]

This is the only forum I've ever found where you can get consistent, meaningful engineering discussion. The reason you're not really getting too many replies is because your question can't be conclusively answered by any one (or even all) of us. I'm not trying to be obstructive, but who are these students you're teaching and why do you not have access to the information yourself?

Most automotive and industrial Diesel engines are jacket water cooled. Some are air cooled. Most are single acting, some are double acting. Most are in-line or vee, some are radial or single cylinder.

Almost all modern automotive Diesels are water cooled, turbocharged, air/air charge cooled, 4 stroke direct injection. Many are now common rail. The automotive sector accounts for the lion's share of all Diesels currently in use, infer from that what you will, or go and have a look at VW, Ford, BMW websites. The application here between different manufacturers is so similar that the configuration of 99% of modern automotive Diesels is the same.

Industrial Diesel engines work in such a wide range of applications that there is no typical configuration.

Go to:

www.cat.com
www.cummins.com
www.perkins.com
www.mak-global.com
www.man-engines.com
www.scania.com

And then come back with further questions. The above sites will cover 95% of industrial Diesel applications.

[ray b]

So can I conclude that a normally aspirated engine among the above configurations cannot exist?

no I am sure there is one or two somewhere
everytype has been tryed
by some one some time
even if a backyard more power guy like tim taylor on the show tool time

now common or comercial sucess is another matter

BTW how are you defining diesel
fuel oil or just no spark plug, pure CI
as I have seen a lot of small glow plug motors
use for model cars boats and most commonly aircraft
they burn nitro mixes
but are sorta CI motors
or are they

[brewnog]

no I am sure there is one or two somewhere
everytype has been tryed
by some one some time
even if a backyard more power guy like tim taylor on the show tool time

now common or comercial sucess is another matter

BTW how are you defining diesel
fuel oil or just no spark plug, pure CI
as I have seen a lot of small glow plug motors
use for model cars boats and most commonly aircraft
they burn nitro mixes
but are sorta CI motors
or are they

Yes.
They run on
what's based on
a Diesel cycle.
The fuel type is
irrelevant; it's only
called Diesel fuel because
that's the type of engine
it's designed
to run in.
Large marine
engines will run on heavy
oil which is nothing like
DERV, but
they're still Diesel engines.