Create your own social network with a free forum.
InvisionFree - Free Forum Hosting
Welcome to Nsdraftroom. We hope you enjoy your visit.


You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile, sending personal messages, and voting in polls. Registration is simple, fast, and completely free.


Join our community!


If you're already a member please log in to your account to access all of our features:

Name:   Password:


Pages: (7) 1 2 [3] 4 5 ... Last » ( Go to first unread post )

 Building an engine tutorial
Sumer
Posted: Jun 26 2007, 03:08 PM


You have way too much time on your hands ...


Group: Admin
Posts: 6,060
Member No.: 8
Joined: 10-April 07



If you do that to a car any good mechanic will shake their head at you. Leaving it for a year and the oil and fuel break down and ruin the engine. What car collectors do is put addatives in the fuel and oil that keep ir from breaking down for that long. One of the bad things about diesel is that it's not that easy to do with it as opposed to gasoline.

You could do that. Although you'd want certian electronics anyway, starter system, glow plugs, fuel injection managment. So it won't be an issue to add a small computer that starts it and runs it on a regular basis when not in use.

Effeciency is a funny thing, it depends entirely on so many factos I honestly can't give you a concrete answer on curves for NS stuff. It's really engine specific. Power is just as odd. You can't just say it will be so effecienct at such a power, it's more relevant to RPM. With a 300 shp engine for instanstance, you're not going to bring it down to 30 shp without really eating up the fuel just to keep the cylinders going so slowly. Your maximum effecient area is within a range of the RPM band where both torque and power are close to eachother. The thing is, lower speed = torque, higher speed = power. This is why gasoline and diesel engines have different ratios of each compared to eachother. So take two engines with an RPM range of 1000 to 8000 rpm, one a diesel one a gasoline. The gasoline engine will be more effecient in the upper band, around say 6000 rpm, and the diesel will be more effecient in the lower band, around 3000 rpm. Superchargers and turbochargers can mess this up like crazy depending on how they're used, like for instance the Lancia Delta S4 with it's compound turbo system (IE both a turbo and a super) managed to have torque and power curves that were not only identical, but virtually flat through 70% of it's RPM band. That's a good thing for what it did, but not so useful in many applications, like this.
So, after that, the short answer to your question is your most effecient range here will probably be around 3000-4000 rpm, putting out around 300 shp if the engine is rated for a maximum of 400-ish shp.


--------------------
QUOTE
“I believe that the sound of racking the pump of a shotgun is universally recognized as ‘kiss your ass goodbye’."

Proudly Canadian
user posted image
QUOTE ("L3 Communications")
Well...next to Sumer's juggernaut of death, the MCA-7G.
Top
Vault 10
Posted: Jun 26 2007, 04:18 PM


Unregistered









QUOTE
If you do that to a car any good mechanic will shake their head at you. Leaving it for a year and the oil and fuel break down and ruin the engine.

Well... still there are people who do that, use an old second car a month in a year (in another place), and the cars still work. Though I well understand it's neglect, but the point is to know if it will work, not strip of maintenance.


QUOTE
You could do that. Although you'd want certian electronics anyway, starter system, glow plugs, fuel injection managment. So it won't be an issue to add a small computer that starts it and runs it on a regular basis when not in use.

Then so be it - the control computer will give the engine a small run once in a while, plus report if any issues arise. Would also do certain things if excessive trim, heel, shock is detected, or damage is reported - open the door, turn on the lights, prepare the engine.


QUOTE
So, after that, the short answer to your question is your most effecient range here will probably be around 3000-4000 rpm, putting out around 300 shp if the engine is rated for a maximum of 400-ish shp.

Hmm... OK, clear on this.
And how much is wasted at low power? Does it make sense to put in an APU to work at low power? I guess the APU here would be a small 2-cylinder boxer engine working at constant RPM to put out 15kW electrical or 20hp.
Top
Sumer
Posted: Jun 26 2007, 05:17 PM


You have way too much time on your hands ...


Group: Admin
Posts: 6,060
Member No.: 8
Joined: 10-April 07



If you really want just go diesel electric, then power is not an issue of fuel. At lower rpms you'll have to use more fuel to ged the deatonation to happen with lower compression that will be in effect. It will certianly be less fuel per minute then at a medium or high one, but it will be more proportionally.
A lot of fishing boats, who's engines must run for weeks without stoping and are usually in the 400-600 shp range will use a small 2 cylinder generator for power supply of things. So they're not hard to get away with. Alternativly you could just design the engine with it's computer to shut down cylinders. This has problems in that it keeps the wear and tear on the engine, and uses more fuel per cylinder, but overall uses less fuel. But I don't see why you'd need it to run at such low power anyway.


--------------------
QUOTE
“I believe that the sound of racking the pump of a shotgun is universally recognized as ‘kiss your ass goodbye’."

Proudly Canadian
user posted image
QUOTE ("L3 Communications")
Well...next to Sumer's juggernaut of death, the MCA-7G.
Top
Vault 10
Posted: Jun 26 2007, 06:39 PM


Unregistered









QUOTE
Alternativly you could just design the engine with it's computer to shut down cylinders.

Hmm, that's interesting. Is it applicable to a semi-mechanically controlled engine, meaning, will I retain the ability to run it on pure mechanics?

BTW, about breakdowns of liquids... Would it make sense to use fuel oil no.4, to reduce losses with time?


QUOTE
But I don't see why you'd need it to run at such low power anyway.

For stationary operation. Just to keep the heating, ventilation, desalinization, lighting, signals alive.

Average 75-kg male human can survive on 8MJ/day of food and 0.5l/day of water for significant periods of time. Food can contain about 20MJ/kg, which, with 32kg/person supply, ensures 80 days of survival, not counting fishing and internal supplies. At the economic speed of 2.5m/s (5kts), taking 20kW to sustain and so 110kg/day, this allows to reach 10,000km (5,500nmi) in 50 days, which even in NS world should be sufficient to get to coast or at least a shipping line, with 30+ days waiting period left.

I'm really not sure if I need it, though, or if I need the 120kW engine. However, providing, even though for only 10 days, this power, it could move the craft at 5m/s (10kts), for 4,000km/2200nmi, to provide faster transport when there's coast close enough.


True diesel-electric, though, might actually be more practical here. Just that certain concerns about reliability might arise. Also, though it could achieve major fuel savings by sailing submerged, that complicates detection too much to consider. OTOH, satellite network density makes transmission from a properly equipped boat likely to be received anyway.
I'd also prefer to keep the total craft cost below half a million, to keep it not just good, but cost-efficient, meaning that, for average accident rate and person's economic contribution, installation of the boat would bring net economic benefit. While lack of that wouldn't be a problem for V10, convincing on international scale would need economic arguments. Electric systems can easily bring cost up.
Top
Sumer
Posted: Jun 27 2007, 01:13 AM


You have way too much time on your hands ...


Group: Admin
Posts: 6,060
Member No.: 8
Joined: 10-April 07



It depends how you design it. In theory you can simly have the computer not inject fuel into the cylinder you want to shut down, and then the only thing that will be needed is electronic fuel injection, all else will be as mechanical as need be.

All fuels and oils break down over time, it can't be avoided. The absolute cheapest and most effecient way of avoiding this is to change the fuel and oils on a regular basis. Luckaly for oils and other lubricants you don't have to change them very often, maybe once a year if you want to keep on top of it. Fuel on the other hand no matter what you use needs to be changed more frequently.

Why would your lifeboat sail submerged?

The engine in your lifeboat won't be too expensive depending. The engine you want, or have expressed wanting, will be quite expensive in the six digit price range. But you can easily go with a more realistic smaller engine in the $8000 range.


--------------------
QUOTE
“I believe that the sound of racking the pump of a shotgun is universally recognized as ‘kiss your ass goodbye’."

Proudly Canadian
user posted image
QUOTE ("L3 Communications")
Well...next to Sumer's juggernaut of death, the MCA-7G.
Top
Vault 10
Posted: Jun 27 2007, 01:23 AM


Unregistered









QUOTE
Why would your lifeboat sail submerged?

Well, not really that it would, but that's a potential way to save fuel at higher speed. More efficient propulsion, less drag, and less waste due to instability. However, not really a good one, since it should stay on surface to be noticed.

QUOTE
The engine you want, or have expressed wanting, will be quite expensive in the six digit price range.

Hmm... Just for 160hp optimal, 270hp top, made of steel, inline 6?
While it's marine, I don't get why would it be costlier or as costly as, for instance, a titanium-ceramics 2000hp one with much more complex design.
Top
Sumer
Posted: Jun 27 2007, 01:26 AM


You have way too much time on your hands ...


Group: Admin
Posts: 6,060
Member No.: 8
Joined: 10-April 07



No for the engine originally posted, the I6 6L one.
Marine diesels come with an array of crap on them, including gearing and bilge systems. My Crower cycle engine, for instance, is the price for the engine alone, no extra systems like electronics and gearing and bilges, just the engine block and stuff attached to it to run. That is, oddly, the cheapest part of the engine system.


--------------------
QUOTE
“I believe that the sound of racking the pump of a shotgun is universally recognized as ‘kiss your ass goodbye’."

Proudly Canadian
user posted image
QUOTE ("L3 Communications")
Well...next to Sumer's juggernaut of death, the MCA-7G.
Top
Vault 10
Posted: Jun 27 2007, 01:35 AM


Unregistered









Well, what I posted is it - 200kW maximum, 120 optimal/sustained.
But six figures? An entire truck with 270hp engine easily fits in five figures; even with 540hp one. Neither do other marine diesels cost like $1000/kW (even turbines are cheaper!). Why would a dumb low-performance diesel cost that much?
Here the electronics are minimal, gearbox is fixed-speed.
Top
Sumer
Posted: Jun 27 2007, 01:52 AM


You have way too much time on your hands ...


Group: Admin
Posts: 6,060
Member No.: 8
Joined: 10-April 07



Because they're designed to be run indefinatly. That adds a lot to the cost.

And once again, I am basing that off your original post nregarding the 400-600 shp engine. I am yet still too lazy to get off my butt and convert kW to hp because I know hp much better then I know kW.


--------------------
QUOTE
“I believe that the sound of racking the pump of a shotgun is universally recognized as ‘kiss your ass goodbye’."

Proudly Canadian
user posted image
QUOTE ("L3 Communications")
Well...next to Sumer's juggernaut of death, the MCA-7G.
Top
Vault 10
Posted: Jun 27 2007, 02:05 AM


Unregistered









QUOTE
Because they're designed to be run indefinatly. That adds a lot to the cost.

But not that much, for medium-speed ones. They go five figures for the power. And this doesn't have to run for many years, just a month at low power.

QUOTE
And once again, I am basing that off your original post nregarding the 400-600 shp engine.

Well, changed now, to 160-270hp.
Top
Sumer
Posted: Jun 27 2007, 02:11 AM


You have way too much time on your hands ...


Group: Admin
Posts: 6,060
Member No.: 8
Joined: 10-April 07



I'll say 200hp even, you're looking an easy $12,000-18,000. With considerations of simplicity to the extreme, and not having to run for more then 2 days straight.


--------------------
QUOTE
“I believe that the sound of racking the pump of a shotgun is universally recognized as ‘kiss your ass goodbye’."

Proudly Canadian
user posted image
QUOTE ("L3 Communications")
Well...next to Sumer's juggernaut of death, the MCA-7G.
Top
Vault 10
Posted: Jun 27 2007, 02:45 AM


Unregistered









Well, now it's another thing...
No, I don't want to sacrifice reliability and efficiency for price, but just that 6 figures would be excessive. I guess, with a good 270hp (160hp typical use) engine, I'm looking at around $80,000 with transmission and equipment included?

It should run for 10-12 days at 160hp, though not non necessarily non-stop, before fuel runs out. Or it has fuel for 5-6 days at 270hp, though, if it's run at full output, probably 5 days aren't even needed. I guess the most it will need to take is up to 30 days at 60hp, with lower loads held by diesel-electric or APU instead.
Top
Sumer
Posted: Jun 27 2007, 02:47 AM


You have way too much time on your hands ...


Group: Admin
Posts: 6,060
Member No.: 8
Joined: 10-April 07



Gearing, bilges, electronics, and the rest, you're probablky able to pull off $45,000. That's effectivly your entire drivetrain right there. $65,000 if you want everything redundant enough to be able to lose entire aspects of the system and have a backup.


--------------------
QUOTE
“I believe that the sound of racking the pump of a shotgun is universally recognized as ‘kiss your ass goodbye’."

Proudly Canadian
user posted image
QUOTE ("L3 Communications")
Well...next to Sumer's juggernaut of death, the MCA-7G.
Top
Vault 10
Posted: Jun 27 2007, 03:52 AM


Unregistered









That's quite nice, then, as the engine cost won't affect the boat significantly and it should fit. If I need more powerful versions, I guess cost/power ratio stays pretty constant, right?
Also, for dimensions, how heavy should it be then?


Now, for one IC issue - Vault 10 has undergone turbinization around 1961-1975, and so isn't supposed to even have a piston engine industry. Considering that a million to a few boats would be needed with exports/licensed included, that's probably not worth building up something. OTOH, your nation seems to have engines produced and exported in large numbers, with long experience, and so would be able to produce the engines better and cheaper than here. So, what about having the engines imported from your nation? I guess they'll be titanium, but hopefully that won't bring problems.
Top
Sumer
Posted: Jun 27 2007, 03:58 AM


You have way too much time on your hands ...


Group: Admin
Posts: 6,060
Member No.: 8
Joined: 10-April 07



The cost will actually slope up as more power is added, and the slope depends on any number of things. If you really want just assume a gentle curve of price, so if you double the engine specs some day then instead of making the price 200%, make it 210% or something.

Dry weight around 700 kilos.

I can do aluminium. ICly I have a major combustion engine industry for government and military use only, electric and alternative fuels have long since taken over the civil sectors. Although you're welecome to. Guarita could always use more expansion, and this would not be something very problematic with export regulations, since it's just a simple engine.


--------------------
QUOTE
“I believe that the sound of racking the pump of a shotgun is universally recognized as ‘kiss your ass goodbye’."

Proudly Canadian
user posted image
QUOTE ("L3 Communications")
Well...next to Sumer's juggernaut of death, the MCA-7G.
Top
0 User(s) are reading this topic (0 Guests and 0 Anonymous Users)
0 Members:
« Next Oldest | Miscellaneous Sector | Next Newest »
DealsFor.me - The best sales, coupons, and discounts for you

Topic OptionsPages: (7) 1 2 [3] 4 5 ... Last »



Hosted for free by InvisionFree* (Terms of Use: Updated 2/10/2010) | Powered by Invision Power Board v1.3 Final © 2003 IPS, Inc.
Page creation time: 0.1864 seconds | Archive