does a diesel electric drivetrain make sense for tanks and other armored fighting vehicles? they use it for trains, submarines, and other large vehicles, so im assuming the engine and batteries and electrical equipment takes up a lot of space, but its 2024, im sure the technology to shrink it all either exists or can be developed shortly. i would like to imagine a scenario where they shut the engine off and run off of pure battery power to lower their heat signature. and the engine would have a way to directly drive the wheels in case of a failure or emergency. or is all of this a nonsensical idea that just over complicates a fighting vehicle for no benefit?
This is basically the concept of fuel cells, it can definitely be done, and the US military at least has absolutely had some R&D on various fuel cell power packs using hydrogen, methane, etc, both direct and generated. Tons of shit, like
>https://www.hydrogen.energy.gov/docs/hydrogenprogramlibraries/pdfs/review19/ia006_centeck_2019_o.pdf
Remember though when all the current kit was first made, military reliability requirements, the need to plug into logistics networks, fuel storage and needs across many different vehicle types (we've standardized as much as possible as "one fuel for fricking everything on land" because it is such a boon for logistics), etc etc etc.
It's not a non-sensical idea, it's just that you can't ever lose yourself in maximizing performance of individual weapons or units without remember the overall system picture. Modern wars are fought by systems, by mass logistics backing mass combined arms. Something that is "lower performance" but can be supported far better can win out in many cases vs something higher performance but a logi queen outside of highly specialized niches, which fighting vehicles definitely are not. Hydrogen directly will not IMO ever happen, it's too much of fricking b***h to deal with. Other hydrocarbons have different tradeoffs but it's hard to make the case. Generator to electric might well happen though for design flexibility and reliability reasons, but it'll take awhile.
>Hydrogen directly will not IMO ever happen
hydrogen insider here. you're correct, at least in the short term. the logistical scale isn't there and h2 is a b***h to store compared to a jerry can. to win a war diesel is what we're stuck with, for now. the best you could do is ammonia, but that;s arguably nastier than diesel
Long term, however, consider the naval applications. If you could somehow get a cryo liquification plant integrated into a nuclear carrier, you could plug the desal system into an electrolyzer and then all of a sudden you have near-infinite jet fuel.
of course this is assuming we could develop fuel cell fighting planes with reasonable power output - but ground testing for Fuel cell civilian aircraft seems promising. would be cool. also bonus points for having hardware capable of colonizing other planets (where there might not be oil to refine)
>Battery vehicles
>lugging heavy, dead weight constantly
>gets cold, stops working
>battery cell gets shot, spontaneously combusts
>have to rely on grunts to be forklift certified to replace literal tons of battery in and out of the tank or wait for hours
vs fuel cell
>all the benefits of BEV
>still works in cold
>5 min refuel time versus 50
>spits out steam for peak CHUGGA CHUGGA
accept fuel cell superiority
I must concede that fuel cells are cool.
HOWEVER
I think batteries are neat. Simple as.
>fuel cell fighting planes with reasonable power output
i completely forgot that H2 is literally rocket fuel. I focus so much safety and AVOIDING fires that i forget that it can blow up and not get me shitcanned. the army used H2 to drive a B-57 engine in the 50s and there are a lot of skunkworks projects for UAVs and other combustion aircraft (picrel)
https://en.wikipedia.org/wiki/Hydrogen-powered_aircraft#History
Hydrogen combustion engines are also, in theory, are easier to retrofit and integrate into existing diesel platforms. it's similar to converting a bus to CNG - you just replace the fuel injection system. Plus you get to keep the VROOM VROOM, (see https://www.youtube.com/watch?v=2dgzKW8EKMc)
based energizer enthusiast
>i completely forgot that H2 is literally rocket fuel.
Though worth noting it has real problems even there and everyone serious is abandoning it going forward for earth launch, though the high ISP will probably continue to give it a role in deep space.
>i completely forgot that H2 is literally rocket fuel
Ok thank you, I was about to call you a moron.
The question is if adding all the weight for a pressurized hydrogen tank is every worth it.
>Fuel cell
Depends on if it's hydrogen or methane. Hydrogen is more powerful but also finicky and tempermental.
>Long term, however, consider the naval applications. If you could somehow get a cryo liquification plant integrated into a nuclear carrier, you could plug the desal system into an electrolyzer and then all of a sudden you have near-infinite jet fuel.
Fuel has other roles in high performance jets though, like as lubricant and coolant itself. I still don't think it's a good match, density is mediocre as well and cyro is hard in an in-atmosphere-for-hours aircraft. If trying to design a more "self-sufficient" carrier I'd lean towards R&D to improve synthetic hydrocarbon plants.
But ultimately I think that's still a dead end, carrier nuclear plants seem powerful relatively speaking but they aren't that powerful at an absolute level. Look at what turbojets actually produce in terms of power, it's in megawatts. 500MW-1GW nuke plant, taking into account losses and so on, really isn't that much vs 75+ fighters flying at high cadence. Hydrocarbons are dense. Any plant is a big use of space that could be directly militarily useful stuff, and it's just not that hard to ship out more fuel. Ships are fricking good and moving ginormous amounts of bulk material, like the best at it. If you can't secure US<>battlegroup shipping enough to have resupply ships make it to the battlegroup and can't sail the battlegroup back closer/cycle it with another I'm not sure fuel is the limiting problem vs enemy somehow gaining naval dominance.
I can certainly see the attraction on paper and have played with it myself but I don't think it works out at all. High perf aircraft will stay on hydrocarbons, it's just they'll be synthetically generated on land. Other stuff will go electric however. Electric could shine replacing all sorts of prop stuff, where you really gain the advantages in reliability and replacing a shitload of plumbing and such.
Honestly, I think turbine electrics would be better but in principle diesel electric has a lot of advantages like regenerative braking and instantaneous power.
>i would like to imagine a scenario where they shut the engine off and run off of pure battery power to lower their heat signature
that's what abrams X is going for, no? I also saw an interesting tractor trailer concept that used diesel electric recently too that got something like 50% increase mileage. Not really sure why this trend hasn't caught on, but I assume it will
im a fricking moron. ignore me, guys. here i thought i had a great fricking idea, only to find out the eggheads beat me to it
>I also saw an interesting tractor trailer concept that used diesel electric recently too that got something like 50% increase mileage.
i know a vehicle's power efficiency loss through the drivetrain is usually around 15%, but are we really at the point where a diesel generator hooked up to electric motors driving the wheels is more efficient from an MPG standpoint than a direct drivetrain? Tesla should just put a tiny diesel generator and fuel tank in the frunk and say frick the climate cult.
yes, not that anon, but electrical engineering anon here, but that's the entire principle behind the chevy volt.
An engine at minimal constant load is way more efficient than one under inconsistent high loads. its the reason the volt gets 200ish mpg vs the 60-80 mpg of a prius.
The only thing more efficient than that direct electric power, which is why EVs don't often sacrifice the weight for a generator.
Where are you getting 200mpg for a volt from?
>are we really at the point where a diesel generator hooked up to electric motors driving the wheels is more efficient from an MPG standpoint than a direct drivetrain?
These drivetrains can be much more effecient if its hybrid power system having buffer battery. Things is engines are oversized for cruise movement, size of the engine is for good acceleration and moving through obstacles (short power surge requirements). Amost of the time engine operates under partial load and combustion engines don't really throttle down effeciently. Small engine operationg at 80% throttle is much more effecient tnan big engine operatiing at 20% throttle with dame power output.
So if you make small engine and hook it to additional buffer battery to provide good acceleration you can make more system with less MPG during cruise.
>does a diesel electric drivetrain make sense for tanks
it adds weight and is energy inefficient
Porsche Tiger/Elefant
>catches fire
GuP-video.webm
you mean like the Porsche tiger had?
Personally I think EVs are the next step. Think of all the shit a turbine or internal combustion engine needs to run, then consider an EV needs-
>Battery
>Motor(s)
>Charge controller/computer
>Brakes?
That's it. No transmission, no driveshaft, no fuel pumps, none of that shit that always has issues, and none of the space those things take up. Yeah obviously a battery bank for a tank is gonna have to be big, but it can be placed pretty much wherever the designers want instead of dictating the entire shape of the vehicle to accommodate the engine and drivetrain.
>But muh charge time for batteries
>*Pulls EV tonk to FoB*
>*Pit crew uses an engine hoist to swap in a new battery in seconds, plugs the one you just had in to be used in the next tank to come back for a refuel*
You can always have a backup generator for emergencies too, or hell have a modular kit that can swap between batteries, a gas generator to power the electric motors, or a smaller battery and smaller generator combo as needed for sortie length/resupply difficulty.
Oh and I guess it'd be pretty quiet too, but I don't really know how much of an upside that would be. If anything it removes the morale boosting PFWOOOOOSSHHH of the Abrams.
>Personally I think EVs are the next step.
batteries that weight as much as the tank
No, batteries aren't even close to the energy density of fuel.. and we're centuries away from that being a possibility. Hybrid is still the best with a powerplant applying constant output, and batteries/capacitors acting as the buffer for various loads
Why do EV morons like yourself have a complete misunderstanding of how automobiles work? EVs have all the complexity of ICE, except they now have a massive battery pack and usually four engines (one at each wheel) to lug around. They only have less parts count if your disingenuous about how electric motors are made.
You're probably a rube that thinks they don't need oil changes too.
>EVs have all the complexity of ICE
EV parts are much simpler, that's why any shitty Chink company is making EV cars.
>all the complexity of an ICE
show me the fuel pump, injectors, and exhaust manifold on an EV idiot
>usually have 4 motors, one at each wheel
there are no major production EVs like this idiot. Most economy EVs have one motor in the same place as an ICE, higher level EVs have 2 (one per axle) or 3 (2 on the rear, 1 in front).
moron bait/10
Electric motors are tested and proven to have less problems than an ICE motor. Also replacing a single faulty electric motor is a lot easier than doing an engine swap or running diagnostics on an ICE. The battery problem is going to be mitigated by better tech. Lithium Ions have improved immensely in 15 years, you cannot even compare the early ones with current batteries.
Baring a massive breakthrough in battery tech that's not going to happen.
Energy density is too shit right now.
And if you could magically cram more energy into a battery it becomes a bomb that goes off when damaged/shorted.
Yes it makes sense. It gets even smarter if we can develop structural housing for axial motors. Suddenly we don't need a single large electric motor, each roadwheel is an independently throttleable motor for movement and torque vectoring.
Adding a "battery" and "Super capacitor" layer into the armor matrix via replacing another element can resolve some of the packaging issues, simply because the tank doesn't need a huge battery. The existing turbine could become a full time generator and just replace the gearbox. Weight and space savings, peak power can be addressed by the capacitor/battery array.
rebuttal
>does a diesel electric drivetrain make sense for tanks and other armored fighting vehicles?
it depends since most industrial diesel engines are only slightly boosted, thus despite initial advantages of diesel they have utter shit specific power output (see leo 2 with 47.6L engine but barely 31,4hp/L which is laughable compared to truck or car engines. granted it was designed in 70s).
unless mindset changes, that YOU NEED low-stressed engine for constant peak-power operation (PROTIP: you don't), and thus you NEED to lug 2.5t engine (PROTIP: you also don't) i really don't see any potential for further reduction in engine size or more boosted designs (adopted from civilian trucks or car) nor any potential for electrification
what i would do, i'd just slap electric variable vane turbo, put medium-duty cycle engine (preferably from truck), remove most emissions crap from it, somehow make it a series hybrid, put maybe 150kwh of batteries.
it doesn't make sense since tanks are all about weight and size reduction to be able to fit more armor, the only problem it solves is not having to design a high performance long lasting main transmission
>it doesn't make sense since tanks are all about weight and size reduction
Diesel-Electric drives are smaller and less mechanically complex than traditional powerplants.
In normal industrial applications sure, in the context of heavily optimized tank components I don't think so. HSWL 295 (main and side transmissions) weighs around 2.5t and is 1.8x0.77x0.84 m3. Can you fit 1.5MVA generator and two 0.75kVA motors within those constraints? I doubt it, not with normal industrial gear, not even if you take the pinnacle of optimization that are airplane IDGs and scale them up to a MVA level. If it was that simple RENK would go bankrupt long ago, in reality everyone either buys their products or spends over a decade to design similar but always a bit inferior domestic alternatives
>does a diesel electric drivetrain make sense for tanks and other armored fighting vehicles?
For just locomotion not really.
But today with emergine direct energy weapons systems electric power train makes sense. So you use main engine for both movement of the vehicle and powering energy weapons (lasers, HPW etc).
>transformer
>rectifier
>inverter
Why? The generator puts out A/C anyways
Most Motors run on DC, the genrator will also put out DC, but it is more efficent to move large amounts of power in AC
probably because the motors need a different frequency or changeable power conversion
or it's actually a switched-mode power supply that are much more efficient (90%) than a generic transformer (50%)
or all at the same time
you are a moron
>you are a moron
What in there is wrong?
>Most Motors run on DC
3 phase motors are for high torque
> the genrator will also put out DC
for lamps
>but it is more efficent to move large amounts of power in AC
something a moron would say who only knows the basics but thinks he's some expert
only a moron would convert between AC and DC to move current a few feet away
Aren't you just a peachy chap?
Never claimed to be an expert, why should I believe you are one?
>why should I believe you are one?
I never claimed it but I also never said something this moronic
>Most Motors run on DC, the genrator will also put out DC, but it is more efficent to move large amounts of power in AC
you are pretty much acting like you are some expert compared that you know literally nothing about electricity
>but it is more efficent to move large amounts of power in AC
also not, it's not more efficient to move it in AC
it's more efficient to move it in high voltage
you're an ass and wrong
you're polite but also wrong
Fresh out of an electric motor class. A lot of motors are DC, 3phase AC, and single+helper phase AC for a list of reasons. 3 phase AC helps with precise speed control (drones, other pwm applications). DC with permanent magnets can have higher torque per watt, because they don't use power on stator windings.
Because motors are AC or DC, generators can also be AC or DC, but generators are always rectified to DC then inverted back to AC to get rid of harmonics and non steady signals from load variations on the generator.
you are full of shit
>but generators are always rectified to DC then inverted back to AC to get rid of harmonics and non steady signals from load variations on the generator.
where did you get this moronic shit from?
>DC with permanent magnets can have higher torque per watt
DC motors have no torque when under high load and will short your power source
>Fresh out of an electric motor class.
stop lying you stupid gay
>3 phase AC helps with precise speed control (drones, other pwm applications).
drones use DC motors
PWM is used with DC
3 phase is used for high torque/load applications
>DC motors have no torque when under high load
I wanted to say they have shit efficiency under load not that they have no torque, but they will basically short your power source when stalled.
>Where did you get that moronic shit from
My 400 level Electrical engineering class last semester you hobbyist grade simpleton. Pic related.
>stop lying
Wheres your credits?
>My 400 level Electrical engineering class
then you got taught moronic shit, or you have no idea what you read.
a hybrid drive is different from this, that's what you probably think of.
the only advantage is high torque at low speeds and one gear gearbox, it's not worth the extra weight and complexity when it's not desperately needed, unlike in trains.
>no rebuttal or credits
pure pottery from an armchair engineer
>moron makes shit up thinking people won't notice
>You're probably a rube that thinks they don't need oil changes too.
yes moron, they don't need oil change.
Electric cars can require oil changes for the gearbox, either due to fault, maintenance or at a high mileage level.
Example: https://service.tesla.com/docs/Model3/ServiceManual/en-us/GUID-C5B5120A-0F8B-406E-95DA-EEC9F63BCDF1.html
of course they need regular maintenance but that moron implied they need the same oil change as an ICE
>destroy tracks
>tank useless
The tracks would be an order of magnitude larger than normal tracks. It would roll over anti-tank mines the same way regular tanks roll over anti-personnel mines.
>Most Motors run on DC, the genrator will also put out DC
you were also too moronic to even google what an inverter is and understand the diagram
It would make sense in that it could be set up to provide redundancy. E.g. two smaller engines with independent cooling systems and generators, and having two electric motors per track, eliminating transmission as a single point of failure entirely.
Putting big, heavy batteries aboard any vehicle that needs to be highly mobile is a big tradeoff and it only makes sense for current gen electric cars because of the use of high-density lithium batteries. Which burn rather spectacularly if damaged. I see what you're getting at but you're not going to get there with current technology. Better to instead have a small APU to provide idling power to minimise signature when not on the move.
used to think it made no sense and wasn't efficient like some anons itt but that's false, it's the future, especially with newer systems requiring more electric power.
I always wondered why this hasn't been widely used on military vehicles since the advantages seem very obvious & is simpler to do than having a conventional drivetrain
Complexity, mostly. You're essentially running two engines in one vehicle. With a train you've got enough space for both but for tanks and cars space is at a premium.
The petrol/diesel engine driving electric power
in series people are talking about here is only efficient with a small engine and big electric motor, ideally your continual load is much less than the peak load. A tank might be able to have a smaller engine if its a series power, due to not needing much torque direct off the diesel engine. But the high constant power demand of manouvering offroad in combat would eventually deplete the batteries if the engine is too small to meet constant load, and you can't just park up and wait for the battery to recharge while someone is trying to shoot you.
Tanks ain't outrunning missiles or shells. It is just neat being able to get over obstructions and break line of sight.
It is not like less mobile vehicles are unusable, its just another set of trade offs. Fuel efficiency and on board power can be useful if the rest of the vehicle role synergizes.
I'm sure it would work fine if you dont mind your tank driving around looking like a Christmas Tree on IR.
Why not gigantic nuclear powered tanks? Because of the energy generation potential, you could have a 600 ton tank with 10x the armor and a 16" gun.
>but sinking in mud
The treads would be superwide and long so it would be just fine on mud.
>but nuclear reactor
10x the armor dude. It would be the killdozer of the battlefield. And with refueling only necessary every 10 years, you could drive zigzags over asia.
If the Russians or Chinese managed to blow one up, destroying the nuke tank basically Chernobyls the area. Other nuke tanks can drive through Chernobyl'd areas no problem, so destroying a nuke tank hurts the enemy more than you.
If we put an 8" gun on it instead of 16", it could carry hundreds of rounds. It would use an autoloader because 10x armor dude.
Thousands of rounds