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Posted by: Rogtuok
« on: March 18, 2013, 08:05:39 AM »

Fuel economies isent that the same as a car and how mutch power you can get out of 1 l of gas example my car with 100 hp use 1 l of gas to go 100 km in 1 houer.   

10 years later you do get 200 hp from 1 l of gas and travel 100 km in 30 minuts.   

In this way you save time.    But on the other hand you could still save some other way her

You take out 100 hp and use 0.   5 l of gas and travel 100 km in 1 houer.   

So other you save time or range.   

Asking for more power and less fuel use aren't feasible 1 unit of energy is 1 unit and not 2 .   
No way I'm going in to all this physic equations

e=mc2 and what ever more equations you whant to use.   

What everything comes down to is how mutch fuel do you use to get the same amount of energy out of the engine. 

Or the revers how mutch energy do you get out from the same amount of fuel.  What you ater decide to do with that energy is up to you more speed or range or more tonnage moved is up to you.
Posted by: Conscript Gary
« on: March 05, 2013, 09:05:13 AM »

Yep. An engine's power output depends on engine tech, power mod, and size. Everything but efficiency tech.
And on the other side of the coin, an engine's fuel efficiency on an EPH basis depends on efficiency tech, power mod, and size. Everything but engine tech.
I would almost call it elegant, but I just might be too deep in the math of it, heh.
Posted by: Charlie Beeler
« on: March 05, 2013, 08:56:15 AM »

Quote from: alex_brunius on March 04, 2013, 09:48:14 AM
Ofcourse it does have everything to do with movements in Aurora.
Actually no it doesn't.  This is a falisy that many new players fall into because there isn't really a published outline of baseline game concepts, it's left up to the veterans of the board to pass these concepts on.  In this case it is that movement is inertialess and reactionless.  This results in no acceleration or turn mode concerns like so many other space simulations.  This was done to keep the support programming very simple. 
Quote
The ship is moving faster which we all agree is off great value, to acomplish this while still not burning any more fuel is indeed an increase in efficiency, but that extra efficiency is spent on increasing speed.

You are ignoring the merit and value of this speed gain and the fact that it in practice easilly can be interchanged for a huge increase in fuel efficiency if the designer of the next generation engine chooses to do so.
Actually I'm ignoring nothing.  What I've taken issue with is what and how you counter posted Ian's conclusion.   

Specifically, you quote Ian's first paragraph
Quote from: IanD on February 13, 2013, 11:53:44 AM
No matter what flavour of engine you use for an identical power output you consume the same amount of fuel per Engine Power Hour. What this means is that a conventional engine is as fuel efficient as a Magneto-plasma drive, just you can generate more power in the same space. There is no  improvement in fuel efficiency as your engine tech improves.

and then attempt refute his observation by
Quote from: alex_brunius on February 26, 2013, 05:53:40 AM
That's actually not quite right.

Let's assume you devote 33% of your ships weight to engines. A more advanced engine that can provide the same power output for half the weight will lead to a more fuel efficient design as your ship just got 16.5% lighter without losing anything.

The lighter ship will go faster but consume the same amount of fuel per hour, thus being more fuel efficient. The bigger engines you use in your designs the bigger this effect will be.
Now I will admit that at first blush it appears that Ian is talking about fully developed ship engines and not just the engine drive tech.  But, when the entire statement is taken into account it becomes obvious that the subject is engine drive tech to the exclusion of fuel consumption and power modifier tech's. By specifying only drive tech as the subject, variable engine size is no longer factored into the conclusion.  This is further reinforced when he specifies "more power in the same space".  At this point it is very clear that one underlying tech is the subject and not implementation of the various tech's available for engine design. 

At this point if you had stated you understood these limitations and where then expanding to engine design to point out that additional tech changes to fuel consumption were not needed I'd have had no problem.  But you instead state that Ian's obeservation/conclusion is in error and go outside the scope he set in making it in the first place. 

Quote
As many have already pointed out a next gen engine with the same power output, size and same fuel effeciency tech would have significantly better fuel efficiency/fuel economy. In the Aurora the universe this is what matters when we build our ships.
Never said differently.  As outlined above it's also off point.
Quote
I acknowledge your theoretical point, but what we are trying to say is that it doesn't matter because in practice more advanced engines will let you design more fuel efficient engines without losing anything, both through a design using a lower fuel burn ratio, or through a design using less space. If More advanced engines also gave you a direct bonus to fuel efficiency then that tech line would become even more powerful and overpowered, it already lets you design better engines (in whatever area you choose to improve) for Starships, Fighters, FACs and Missiles, I think it's powerful enough.
It's not theoretical, it's fundimental Aurora mechanics and the rebutals are off point.  As a seperate discussion about engine design and tech impact on fuel consumption you would be correct. 
Posted by: Nightstar
« on: March 04, 2013, 05:17:07 PM »

You people keep reading the words "power output" as "power modifier".  ;)  To keep the same power output, you need to reduce power modifier.
Posted by: Conscript Gary
« on: March 04, 2013, 04:26:19 PM »

Quote from: alex_brunius on March 04, 2013, 09:48:14 AM
As many have already pointed out a next gen engine with the same power output, size and same fuel effeciency tech would have significantly better fuel efficiency/fuel economy. In the Aurora the universe this is what matters when we build our ships.

Actually an engine that is identical in those three regards will consume the same amount of fuel for every hour of thrust it delivers. If mounted in the same frame, the one with the more modern engine tech will indeed go faster. It will also burn fuel faster. And since those are directly proportional, it will be able to travel the same distance, just in varying amounts of time.
Engine tech does increase the baseline of thrust you can deliver, but doesn't affect how much fuel is consumed for each EPH.
Posted by: alex_brunius
« on: March 04, 2013, 09:48:14 AM »

Quote from: Charlie Beeler on March 03, 2013, 08:37:53 AM
Your analysis related to joules for thrust is a nice touch that has nothing to do with movement in Aurora.  The basis of Aurora drives is that it is inertialess and does not adhere to Newtonian physics.  Kinetic energy does not apply.  No acceleration.  So all that detail work is irrelevant to the discussion.
Ofcourse it does have everything to do with movements in Aurora.

The ship is moving faster which we all agree is off great value, to acomplish this while still not burning any more fuel is indeed an increase in efficiency, but that extra efficiency is spent on increasing speed.

You are ignoring the merit and value of this speed gain and the fact that it in practice easilly can be interchanged for a huge increase in fuel efficiency if the designer of the next generation engine chooses to do so.

As many have already pointed out a next gen engine with the same power output, size and same fuel effeciency tech would have significantly better fuel efficiency/fuel economy. In the Aurora the universe this is what matters when we build our ships.

I acknowledge your theoretical point, but what we are trying to say is that it doesn't matter because in practice more advanced engines will let you design more fuel efficient engines without losing anything, both through a design using a lower fuel burn ratio, or through a design using less space. If More advanced engines also gave you a direct bonus to fuel efficiency then that tech line would become even more powerful and overpowered, it already lets you design better engines (in whatever area you choose to improve) for Starships, Fighters, FACs and Missiles, I think it's powerful enough.
Posted by: Charlie Beeler
« on: March 03, 2013, 08:37:53 AM »

Rod-Sterling, so happy that your upset.  It made you look deeper into the subject didn't it. 

I do thank you for an excellent example of bypassing the point. 

Whether the proper term is efficiency or economy, they are habitually used interchangeably on this board for discussing engine fuel use, Ian's statement that drive tech advancement does not change the fuel needed to cover a set distance is quite correct.  The key points are that only drive tech changes are specified and that the engine size is constant.  I infer, yes this may be incorrect, that Ian's intent is refitting existing ships with new drive techs.   

Your analysis related to joules for thrust is a nice touch that has nothing to do with movement in Aurora.  The basis of Aurora drives is that it is inertialess and does not adhere to Newtonian physics.  Kinetic energy does not apply.  No acceleration.  So all that detail work is irrelevant to the discussion.

Within Aurora fuel consumption has a baseline of 1 liter produces 1 engine propulsion point per hour.  This does not change from one drive tech to another, period.  This function is what Ian's post is pointing out.  Not advancing tech for Fuel Consumption. Not Maximum or Minimum Power Modifiers. And specificly not different sized engines.  All of those do have a direct effect on fuel consumption. 
Posted by: Conscript Gary
« on: March 02, 2013, 09:11:26 PM »

I'd rather stick to the definition of fuel efficiency used by the game, that of how much fuel is consumed per unit of engine power. Semantics just bog down an argument.

In which case yes, propulsion technology has no bearing on the liters of fuel required to produce an hour of engine power.
Engine size, power modifier, and fuel consumption tech do. Should propulsion technology be included in that list? I would lean towards saying no. Those three existing factors provide plenty of room for playing with efficiency in my opinion. Fuel tech lets you use less fuel with no bearing on speed. Engine tech lets you go faster with no bearing on fuel usage. Two sides of the same coin.

(also I stuck some spiffy color-coding to the results on those spreadsheets)

edit: And then I got curious as to the gains/lack thereof from matching power from differing engine sizes and made yet another spreadsheet.



Holding power modifier, fuel consumption tech and ship components fixed, and using smaller engines to match the old in power output. Engine ratio is 0.25. Results in:
Increased fuel consumption to the order of ~20% with a size-50 starting engine that peters off to parity at smaller sizes.
Increased range to the order of ~15% with a size-50 starting engine that peters off by size-21.
Decreased range starting at size-20 engines, ending at around a ~5% loss for miniature engines.

Those trends were fairly consistent across upgrades, which fits the math, so I wondered how the engine ratio factored into things, with several fixed starting engine sizes.



Engine ratio (Total size / Engine size) has no bearing on fuel consumption, as expected by the math.
But as the ratio of engine-to-ship increases, the less possible it is to increase your range with a size-based upgrade.

So unless you consider ~5-15 HS less of a target cross section to be worth having no upgrade in speed, barely any upgrade in range, and an increase in fuel usage, it's not a terribly viable upgrade method.
Posted by: Rod-Serling
« on: March 02, 2013, 08:07:58 PM »

Charlie Beeler, I've got to admit, you've made me a little upset due to your attitude toward this discussion. You obviously think you are right and that IanD's statement is correct, and you blatantly disregard many good points by other members simply because they do not fall in to what you consider to be the realm of the discussion. They were, however, relevant. If the engines had the same fuel efficiency, then they would be completely identical.   
In any case, both you and IanD are incorrect in any case, and like you said yourself. . .

Quote from: CharlieBeeler link=topic=5930.   msg60701#msg60701 date=1362160665
The devil is in the details.

For my analysis I will gladly adhere to your rules. Power / Efficiency Modifiers will remain at 1. Fuel Consumption will remain at 1, and engine size will remain a constant 10HS.   

However, trans-newton engines are very special. They don't exist in the real world obviously, and exhibit very strange characteristics. The most important characteristic is that they constantly require fuel to maintain their speed. This is very much like a commercial airliner, or an automobile, and very much unlike a traditional spacecraft. This implies that Trans-Newton engines are affected by some kind of Trans-Newton drag.   

Now I'm by no means an expert in physics, I have the basic understanding that to maintain speed while under the effects of drag, a force of identical magnitude of the drag must be applied from the other end.   

So, in Aurora terms, that TN engine that sports a 500km/sec top speed, is constantly accelerating at 500km/sec^2, and being pushed back by drag at 500km/sec^s


Now, let's look again at the original quote.   

Quote from: IanD link=topic=5896.   msg60215#msg60215 date=1360778024
No matter what flavour of engine you use for an identical power output you consume the same amount of fuel per Engine Power Hour. What this means is that a conventional engine is as fuel efficient as a Magneto-plasma drive, just you can generate more power in the same space. There is no  improvement in fuel efficiency as your engine tech improves.   

This doesn't seem quite right. Almost like (in wet navy terms) as saying a reciprocating steam engine is as efficient as a high pressure steam engine is as efficient as a diesel engine is as efficient as a nuclear reactor.   

With the recent changes to fuel requirements it is surely not beyond the realms of possibility to increase engine efficiency as the tech improves.     

hxxp: en. wikipedia.  rg/wiki/Fuel_efficiency
Quote
Fuel efficiency is a form of thermal efficiency, meaning the efficiency of a process that converts chemical potential energy contained in a carrier fuel into kinetic energy or work

Now, let's take a look at Conscript Gary's excellent spreadsheets.   

A Size-10 Nuclear Thermal Engine can push our 2000-Ton craft 50 billion kilometers at a rate of 1,250km/sec using only 500,000 liters of fuel.   
A Size-10 Nuclear Pulse Engine can push our 2000-Ton craft 50 billion kilometers at a rate of 2,000km/sec using only 500,000 liters of fuel.   

We already know how much "carrier fuel" we transferred into "kinetic energy or work", it was 500,000 liters in both cases. But how much work did each engine do?

Let's use Joules.   
J=N*m
N = Newtons of force applied
m = meters the force was applied for.   

So, so how many Newtons?

N = kg*A
kg being the weight of the object
A being the acceleration in m/s^2

Our 2000-ton craft weighs 2,032,093kg (Long Ton, it's not written tonnes and Steve is from London, you could use Short or Metric tons, result will be the same)

Our NTE is accelerating at 1,250,000m/s^2, providing 2,540,116,250,000 Newtons of force
Our NPE is accelerating at 2,000,000m/s^s, providing 4,064,186,000,000 Newtons of force

J=N*m
We burned for 50,000,000,000,000 meters, so
J=N*50 trillion
Our NTE converted 500,000 liters of fuel into 127.   005812 Yottajoules of work.   
Our NPE converted 500,000 liters of fuel into 203.   2093 Yottajoules of work.   
(1 Yottajoule = 1,000,000,000,000,000,000,000,000 joules)

This means that a Nuclear Pulse Engine is 60% more fuel efficient than a Nuclear Thermal Engine.   

This increase in fuel efficiency allows us to go faster, or go farther, depending on your needs. If the engines had the same fuel efficiency, then they would literally be identical. Your only chance to change anything would be to change the power modifiers, size, and other stuff.   

Now where you and IanD get mixed up, is that Fuel Efficiency is not the same as Fuel Economy. I'm going to quote our ever-reliable source, wikipedia.
hxxp: en. wikipedia. org/wiki/Fuel_economy_in_automobiles#Fuel_economy_statistics
Quote
While the fuel efficiency of petroleum engines (the ability to transform the chemical energy of the fuel into power) has increased since the beginning of the automotive era, this has not necessarily resulted in greater fuel economy or less fuel consumption. The mass, shape, and size of a car, also affect fuel economy and so does the automobile's design, which may be to produce more power and speed rather than greater economy and range.   

In conclusion, IanD is completely wrong. Engine Technology advancement is directly increasing fuel efficiency. Fuel economy, however, is a different issue, and depends on the design of the engine. But we wern't talking about fuel economy were we?
Posted by: Conscript Gary
« on: March 01, 2013, 07:02:12 PM »

Now to address the original argument I made a copy of that spreadsheet and held power modifiers constant but varied engine size from 20 to 1.

Now, let's compare between these two methods of engine upgrade. 1) Using a lower power modifier in the same engine size and 2) Using the same power modifier in a smaller engine.
I'll only consider cases here where the speed after the upgrade does not go down, though the full data for all modifiers and sizes below the datum are available in the aforementioned spreadsheets here and here. I'll only walk through the ion -> magneto-plasma upgrade in this post, but again the rest of the charts are in the docs.

1) Reducing power output in a fixed engine size though reduced power modifiers



At an equal power modifier, a speed increase of 33% is attainable with no change in range
At an equal power output, a range increase of 105% is attainable with no change in speed

2) Reducing Power output at a fixed power modifier through reduced size engines



At an equal size, a speed increase of 33% is attainable with no change in range
At a nearly equal power output, a range increase of 0.57% is attainable with a speed increase of 0.9%

I think those numbers speak for themselves
Posted by: TheDeadlyShoe
« on: March 01, 2013, 04:06:57 PM »

interesting discussion at any rate. going through the math was informative.
Posted by: Conscript Gary
« on: March 01, 2013, 03:51:53 PM »

I can comment on the numbers when I'm at a proper computer, but the graphs at the bottom of each sheet should get the basic point across: that when sizes are fixed and all efficiency techs are equal, upgrading an engine to the next level of propulsion tech can result in an increased speed with no change in range (as is typically done), an increased range with no change in speed, or some happy medium. All within the bounds of the base power modifier tech (base minimum modifier is 0.5 modifier right? Has to be, otherwise you couldn't make commercial engines)
Posted by: Charlie Beeler
« on: March 01, 2013, 11:57:45 AM »

Now look at the entire quote.  Ian is very specific in drive tech progression is what is being addressed.  That fundamental statement is correct.  Nothing about advancing the drive tech, drive tech only, improves fuel efficiency.  Only other implementation factors effect fuel efficiency.

The devil is in the details.

For clarity here is the entire original post....

Quote from: IanD on February 13, 2013, 11:53:44 AM
No matter what flavour of engine you use for an identical power output you consume the same amount of fuel per Engine Power Hour. What this means is that a conventional engine is as fuel efficient as a Magneto-plasma drive, just you can generate more power in the same space. There is no  improvement in fuel efficiency as your engine tech improves.

This doesn't seem quite right. Almost like (in wet navy terms) as saying a reciprocating steam engine is as efficient as a high pressure steam engine is as efficient as a diesel engine is as efficient as a nuclear reactor.

With the recent changes to fuel requirements it is surely not beyond the realms of possibility to  increase engine efficiency as the tech improves. 
Posted by: Nightstar
« on: March 01, 2013, 11:13:43 AM »

You poor thing.

Anyway, perhaps I should rephrase. While you're right about smaller engines not necessarily being more fuel efficient, this is irrelevant to the real discussion: Higher tech engines being more fuel efficient.

This quote, right at the very top of the topic:
Quote from: Ian
No matter what flavour of engine you use for an identical power output you consume the same amount of fuel per Engine Power Hour.
It's dead wrong. Alex's post is true anyway, barring external things like having to use smaller engines.
Posted by: Charlie Beeler
« on: March 01, 2013, 11:09:30 AM »

Quote from: davidb86 on March 01, 2013, 11:06:19 AM
Charlie,

Ian did post "that efficiency per EP does not change as drive tech advances".  But he did this in the context of a suggestion that efficiency should be tied to the base engine tech.  The reason that many players find this unreasonable is that as has been shown by this thread, efficiency is not only it's own tech branch, but can also be modified by design considerations regardless of tech level.  The statement that efficiency should be tied to base engine tech is equivalent to complaining that you have to research multiple tech lines to make any of the weapon systems work instead of researching a single tech and getting a working weapon as was done in Starfire. 

Yes it is a true statement, but it misses the point that this is not a bug, an oversight or an unintended consequence; but a deliberate design choice that Steve made to allow more than one way to solve the tactical problems

I'm fully aware of that.  Please note that this seperation topic starts with Alex's reply post.