Aurora 4x
VB6 Aurora => VB6 Mechanics => Topic started by: Steve Walmsley on April 13, 2012, 05:36:49 PM
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Engines
I've completely changed engine design for v5.70. This shares a lot in common with the Newtonian Aurora engine design, although without the real world physics. Different engine platforms no longer exist, so you will no longer research "FAC" and "fighter" engine types. Engines are classed as "Commercial" for maintenance purposes unless they trigger a "Military" flag - more on that later. The elements of engine design are now as follows:
Engine Technology: This is exactly as before. The engine technology names are the same and the amount of engine power per HS of engine for each type is the same.
Fuel Consumption: This is similar in concept to the old Fuel Efficiency, although it is now modified by other factors in engine design. Fuel Consumption is far more important than in the past. The initial consumption rate starts at one litre per Engine Power Hour (which is one point of engine power for one hour). So an engine with 25 power using the base fuel consumption technology would use 25 litres of fuel per hour. Additional technology levels will lower the fuel consumption rate (0.9 litres per EPH, 0.8 litres per EPH, etc.). On the engine design summary an engine is rated in the total number of litres of fuel per hour it consumes and also the amount per Engine Power Hour. The total amount is derived from Engine Power x Fuel Consumption per EPH. So an Engine with 15 power and a Fuel Consumption per EPH of 0.5 would consume 7.5 litres of fuel per hour.
Engine Size: You can now select the size of engine from 1 HS to 50 HS. Larger engines are more fuel efficient so fuel consumption is reduced by 1% for every HS of engine. For example, a 10 HS engine reduces fuel consumption by 10% and a 25 HS engine reduces it by 25%. There is no longer any restriction on the number of engines so you can have twin engined fighters if you wish.
Thermal Reduction: As before, this reduces the thermal signature of engines, which, without thermal reduction, is equal to their power.
Power / Fuel Consumption Modifiers: There are two new tech lines to research, called Max Engine Power Modifier and Min Engine Power Modifier. These establish the range within which you can change engine power from that provided by the base engine technology. Increasing power increases fuel consumption per EPH and decreasing power can provide significant savings in fuel consumption. Power can be increased by up to 300% of normal and decreased to 10% of normal if you have the prerequisite techs. The dropdown on the design window will have options from the minimum possible to the maximum possible in 5% increments. So 40%, 45%, 50%, 55% ...... 180%, 185%, etc. Each engine power modifier percentage is accompanied by a fuel consumption modifier, based on the formula Fuel Consumption Modifier = (4 ^ Engine Power Modifier) / 4.
For example, assume you choose to increase Engine Power to 50% greater than normal. The Fuel Consumption would be (4 ^ 1.5)/4 = 2, so for a power increase of 50%, the fuel consumption per EPH would increase by 100%. Bear in mind that if the engine power has increased by 50% and the fuel consumption per EPH has increased by 100%, then the total fuel consumption per hour for the engine is 3x higher than before. This is shown on the dropdown as "Engine Power +50%. Fuel Consumption per EPH +100%".
Crew Requirement: The crew requirement for engines has been significantly reduced. It is now equal to Engine HS x 2 x SQRT(Power Modifier). So an engine with 5 HS and a 25% increase in power would require a crew of 5 x 2 x SQRT(1.25) = 11.18 (rounded to 11). The old method was simply Engine HS * 5.
Here is the design summary for an engine of 5 HS, using Magneto-plasma Drive technology and Fuel Consumption technology of 0.6 per EPH with a 25% increase in power and no thermal reduction.
Magneto-plasma Drive
Engine Power: 100 Fuel Use Per Hour: 80.61 Litres
Fuel Consumption per Engine Power Hour: 0.806 Litres
Engine Size: 5 HS Engine HTK: 2
Thermal Signature: 100 Exp Chance: 12
Cost: 100 Crew: 11
Materials Required: 25x Duranium 75x Gallicite
Military Engine
Development Cost for Project: 1000RP
Because of the power modifier the fuel consumption per EPH is increased by 41% and due to the size of the engine the fuel consumption per EPH is decreased by 5%. The Fuel Consumption per EPH is calculated as the base racial technology of 0.6 litres per EPH, x0.95 for engine size, x1.4142 for the 25% engine thrust modifier, which equals 0.8061. Fuel use in litres per hour is therefore 100 power x 0.8061 = 80.61 litres.
Now lets look at an engine designed with fuel consumption as a priority. This is an engine of 25 HS, using Magneto-plasma technology, with an 80% decrease in thrust and no thermal reduction.
Commercial Magneto-plasma Drive
Engine Power: 80 Fuel Use Per Hour: 11.88 Litres
Fuel Consumption per Engine Power Hour: 0.148 Litres
Engine Size: 25 HS Engine HTK: 12
Thermal Signature: 80 Exp Chance: 2
Cost: 80 Crew: 22
Materials Required: 20x Duranium 60x Gallicite
Commercial Engine
Development Cost for Project: 800RP
The Fuel Consumption per EPH is calculated as the base racial technology of 0.6 litres per EPH, x0.75 for engine size, x0.3299 for the -80% engine power modifier, which equals 0.148455. Fuel use in litres per hour is therefore 80 power x 0.148455 = 11.8764 litres per hour. So while this engine produces eighty percent of the power of the previous engine, the total fuel consumption is eighty-five percent less (about 82% less in terms of fuel per EPH). However, it is five times larger so the base speed is much lower and you will use a little extra fuel pushing the mass of the engine itself. The result is that a ship with this engine will take longer to get there but it will use a lot less fuel on the journey. Note this is classed as a commercial engine and the one above was classed as military. Any engine that exceeds 50% base engine power or is smaller than 25 HS is classed as military for maintenance purposes.
Changes relating to Fuel
As fuel consumption is now higher than in the past, I have made a number of changes to systems related to fuel.
Gas giants have a 50% chance of Sorium compared to 20% in the past. The minimum accessibility for gas giant Sorium is 0.3.
Fuel Harvesters have been reduced in size and cost by 50%. Their crew requirement has been reduced by 80%
Three new Fuel Storage Systems have been added. They are shown below with the current 1 HS system for comparison. Fuel Storage systems no longer require any crew.
Fuel Storage (1HS): 50,000 litres, 10 BP
Fuel Storage - Large (5 HS), 250,000 litres, 30 BP
Fuel Storage - Very Large (20 HS): 1,000,000 litres, 70 BP
Fuel Storage - Ultra Large (100 HS): 5,000,000 litres, 200 BP
Steve
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All familiar, my having read the NA thread, but it's going to be cool to see it in the game. The flexibility will add an interesting layer to ship design, but far more importantly, It'll be nice to be able to visualize my Freighters as having a few large jets in the back instead of 16 little ones.
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This sounds very interesting, can't wait to design new ships with the new rules!
It seems as if there will be little reason to have multiple engines, when one big engine will be more efficient. Less research with multiples, and slightly better damage redundancy. Anyone else have thoughts?
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This sounds very interesting, can't wait to design new ships with the new rules!
It seems as if there will be little reason to have multiple engines, when one big engine will be more efficient. Less research with multiples, and slightly better damage redundancy. Anyone else have thoughts?
Well, on the large end a 50 HS engine wont be enough for particularly large ships (It's what, the equivalent of 2 commercial or 10 military engines?). Freighters are probably going to want at least 2-3, and any warship above 10,000 tons will want multiple as well.
Practical effects, commercial ships will probably be much faster, fighters and FACs much less efficient (but longer ranged). Quicker fuel burn will probably mean building fuel stations/depots is more important, as well.
What will control whether a ship is a fighter for construction/organization purposes?
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Engine Size: You can now select the size of engine from 1 HS to 50 HS.
Ah, yes, that's what I was missing! I mistakenly figured we could make arbitrarily large engines.
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Practical effects, commercial ships will probably be much faster, fighters and FACs much less efficient (but longer ranged). Quicker fuel burn will probably mean building fuel stations/depots is more important, as well.
What will control whether a ship is a fighter for construction/organization purposes?
Fighter definition will stay the same as it is now. Anything under 500 tons is classed as a fighter. Fighters won't be as drastically affected in fuel terms as the fuel multiplier for a "fighter engine" equivalent, which under the new system would be an engine with a 3x power modifier, is now 16x normal rather than 100x normal in v5.60.
The other major difference is you can build "fighter engines" that are actually more fuel efficient than before. So you should be able to create a 1 HS engine that allows a small craft to travel a lot further than current fighters. For example, using the same tech as the main example (Magneto-plasma, 0.6 litres per EPH), shown below are a 300% power 1 HS engine and a 50% power 1 HS engine. For comparison, the NATO Magneto-plasma fighter engine from my last campaign (which had 0.6 fuel efficiency) had 48 power and could travel for 34 hours on 10,000 litres.
The Max Power engine can provide that same power for 22 hours, so an identical fighter using the old and new engines would have 2/3rds its previous range. Of course, adding a tiny fuel tank (+5000 litres) would only add 0.1 HS (5 tons) to the fighter and increase endurance to 33 hours. The Shuttle Engine only has 1/6th of the power (and therefore 1/6th speed) but with 10,000 litres of fuel has an endurance of almost six months, allowing you to build extremely long range "fighters". Of course, anything in between is now possible too as the power increments you can select are separated by just 5%.
Max Power Fighter Engine
Engine Power: 48 Fuel Use Per Hour: 456.19 Litres
Fuel Consumption per Engine Power Hour: 9.504 Litres
Engine Size: 1 HS Engine HTK: 1
Thermal Signature: 48 Exp Chance: 30
Cost: 48 Crew: 3
Materials Required: 12x Duranium 36x Gallicite
Military Engine
Development Cost for Project: 480RP
Shuttle Engine
Engine Power: 8 Fuel Use Per Hour: 2.38 Litres
Fuel Consumption per Engine Power Hour: 0.297 Litres
Engine Size: 1 HS Engine HTK: 1
Thermal Signature: 8 Exp Chance: 5
Cost: 8 Crew: 1
Materials Required: 2x Duranium 6x Gallicite
Military Engine
Development Cost for Project: 80RP
Steve
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Took the freedom to calculate the consumption rates for low values;
Damn I miss the new excel at work.It's an .xls, but you can't upload that here, so I renamed it.
One question: Why would anyone build a twin-engine fighter?
Is there a maneuverability bonus or anything?
Ok, got an another one:
I didn't quite get how an engine will be marked military. Where in the text do I find it? Read it twice, still somewhat clueless. ???
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Engines under 25 HS will be Military.
Note this is classed as a commercial engine and the one above was classed as military. Any engine that exceeds 50% base engine power or is smaller than 25 HS is classed as military for maintenance purposes.
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One question: Why would anyone build a twin-engine fighter?
Is there a maneuverability bonus or anything?
No bonus. If someone has designed a 1 HS engine they may decide to use two of those for a fighter rather than designing a new 2 HS engine, especially if they are building the engines with construction factories.
Ok, got an another one:
I didn't quite get how an engine will be marked military. Where in the text do I find it? Read it twice, still somewhat clueless. ???
"Any engine that exceeds 50% base engine power or is smaller than 25 HS is classed as military for maintenance purposes."
It's the last sentence before "Changes Relating to Fuel".
Steve
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No bonus. If someone has designed a 1 HS engine they may decide to use two of those for a fighter rather than designing a new 2 HS engine, especially if they are building the engines with construction factories.
"Any engine that exceeds 50% base engine power or is smaller than 25 HS is classed as military for maintenance purposes."
It's the last sentence before "Changes Relating to Fuel".
Steve
So will 500 1HS engines provide the same thrust as a 500 HS engine?
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From what I can tell, yes, but at a reduced fuel efficiency (or more accurately, without the fuel efficiency bonus associated with size).
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So will 500 1HS engines provide the same thrust as a 500 HS engine?
Max Engine Size is 50 HS. 50 1 HS engines would have the same power as 1 50 HS engine but they would use twice as much fuel.
Steve
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As any engine over 50% becomes military in the new system, will it no longer be possible to have the equivelent of the current high power/low efficiency conventional engines?
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As any engine over 50% becomes military in the new system, will it no longer be possible to have the equivelent of the current high power/low efficiency conventional engines?
In both v5.60 and v5.70, the conventional engine is just a much lower power version of the TN engines. It has 0.2 power per HS compared to 5 power for the Nuclear Thermal Engine.
Steve
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I'm trying to crunch the numbers in the example. Where does the 1.4142 come from in
1.4142/100= 141%, or 41%> the original 100%
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Sorry, figured it out. I had hoped I deleted it before someone responded :P Anyway, here's my notes if anyone's interested.
Using this engine:
FTR Internal Confinement Fusion Drive E780
Power Output: 69 Explosion Chance: 60 Efficiency: 78 Thermal Signature: 11.04
Engine Size: 1 HS Engine HTK: 0
Cost: 26 Crew: 5
Materials Required: 6.5x Duranium 0x Neutronium 19.5x Gallicite
Development Cost for Project: 260RP
Fuel Capacity 10,000 Litres Range 0.9 billion km (18 hours at full power) 13800 km\sec
Power Efficiency -30, Power Increase 15%, Exp 12%
Fuel Efficiency 4, Fuel Usage x0.6
Thermal Reduction: Signature 16% Normal
With this in the old rules I get an 18.58 hour cruise time, a speed of 13,800 km/sec, and a range of 894,240 megaklicks.
If I take the new engine design specs, for a 60 power engine (3x) I have a 15.25 hour cruise time, a speed of 12,000 km/sec, and a range of 658,800 megaklicks.
To compare, a 40 power engine (2x) has a whopping 105.22 hour cruise time a speed of 8,000 km/sec, and a range of 3,030,336 megaklicks.
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One of my current fighter designs in 5.60 uses exactly the above engine. It is now 255 tons at 14705 km/s, will be 285 tons with 12105 km/s (possible armor increase not considered). The range is the same.
If I put another 50 ton engine on it, it is 335 tons and 20600 km/s! With doubled fuel capacity: 350 tons and 19700 km/s. 5.70 has fighters of much higher performance. Even with only 30% thrust increase tech.
With more thrust increase, given no changes in missile engine tech, it will be possible to design fighters which outrun their own (NATOvsSoviet-esque NATO standard) missiles.
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Ton per ton the old rules had fighter engines with a higher power to weight ratio with better fuel usage for the same power modifier. The new rules make engines a much trickier proposition and much deeper: system defense fighters could have a 1HS engine with lower power for greatly improved range, while short ranged interceptors could use a 2 or 3 HS engine for superior performance and a slight efficiency increase for drastically reduced range. I might design an F-2 sensor fighter (carries the active sensor for the F-1s, no armament and same speed + slightly greater endurance) with a larger, lower-power engine and extra fuel storage to act as a sensor fighter\tanker. Ooh, can't wait until the update. :D
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In both v5.60 and v5.70, the conventional engine is just a much lower power version of the TN engines. It has 0.2 power per HS compared to 5 power for the Nuclear Thermal Engine.
Steve
Ahh, yes I was tired and forgot to factor in the increased size of current comercial engines. Was just remembering that with equal percentage of tonnage in engines commercial are half the speed.
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Will we be able to add multiple engines and switch them on and off?
I totally want to make my cruisers with slow cruise engines and a bunch of small combat thrusters. :D
Steve, regarding the "maneuverability", and fully aware that in a non-newtonian environment such a thing doesn't actually exist, couldn't you add a tiny bonus, like 0.5 power, to the ships speed per engine used? That aside;
Will higher powered engines still have a higher chance to explodonate?
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Hmmm... I like most of the new system, but I see little reason to design anything other than the largest possible commercial drives. Currently the only ships I build that use a single commercial drive are low tech survey ships. I expect that will depend on the RP premium, naturally...
Is there still going to be a military/commercial jump drive distinction?
And are engines still going to be one engine type per ship?
//throwaway idea: the amount at which you can vary the power/fuel consumption of an engine is inverse with the engines size. Meaning you can modify a smaller engine to be overpowered with less technology than a larger engine. So an advance in power technology would either let you build a larger engine with the same power boost (=more fuel efficient) or a same size engine with a larger power boost (=more boost).
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I'd love multiple engine types as well, but I can see where that would be a whole can of worms to implement. It would be extremely fun to have a small cruise engine mounted on a warship, very efficient and slow as it "marches" through systems, but then turning on the main thruster as it "charges" into battle. And civilian ships could be mounted with normal drives and "emergency escape" drives.
Also, how will hyperdrive play into the new engine designs?
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And are engines still going to be one engine type per ship?
Good question! I'd like to know as well.. intriguing suggestions for dual engine designs above.