
How Do You Make Turbo Engines More Efficient? Just Add Water - CapitalistCartr
http://www.nytimes.com/2016/09/30/automobiles/how-do-you-make-turbo-engines-more-efficient-just-add-water.html
======
kls
The process is actually more efficient with a 50/50 mix of water and methanol.
When the water reaches threshold there is additional release of oxygen which
at temperature can be consumed by the combustion of methanol, thus reducing
overall fuel consumption while increasing efficiency. This has been done in
the diesel world for years.

~~~
philipkglass
How does that work? Water will dissociate into hydrogen and oxygen at very
high temperatures, but the mixture of hydrogen and oxygen so produced is
already stoichiometrically balanced. There's no surplus oxygen left to be
reacted with additional fuel.

~~~
kls
The confusion was on my part, I used release of oxygen but it is probably
better explained as intake of oxygen, the cooling effect of the water leads to
a higher air density in the mix of atomized air. The water is not releasing
more oxygen rather there is more air in the cooler denser mixture of air,
water and methanol, the water vaporizes thus creating more volume and then the
methanol flashes and consumes the additional oxygen that is brought in via a
cooler intake, it is my understanding that this oxygen is only available after
the flashing of atomized water into gas, thus I used the term release (which
is a poor choice of words for the process). It works similar to an inter-
cooler, but unlike an intercooler the mix seems to preserve some oxygen for
the methanol combustion cycle so it is more targeted then just forcing more
oxygen into the intake via a denser volume of air (e.g intercooling). Sorry
for the confusion on what is actually happening, you are correct it is not
separating hydrogen atoms from oxygen atoms. If that where the case then as
you said, there would be no need for the methanol as it would be generating
the additional fuel via hydrogen and oxygen in the generated browns gas to
burn it.

------
dfsegoat
Not an engineering expert --- but isn't this the same idea that was being used
in aircraft engines to get the max power out of turbine engines?

The B-52 is the classic example (nasty exhaust plume is the hallmark of these
water injected engines):

[https://youtu.be/xfTdRF66QPo?t=218](https://youtu.be/xfTdRF66QPo?t=218)

edit: I thought they phased this out in the 60's but was surprised to see the
video above was from 1989!

~~~
ucaetano
Exhaust plume? Silly you, those are chemtrails!

------
csours
In another interview about this tech, Bosch said that the engine will not be
allowed to run as hard if the system detects there is no water - so you
basically have a non-water enhanced system when you're out of water.

------
ahh
I'm not an engine expert, but I thought a substantial disadvantage of water
injection was incomplete combustion (see for example the billowing smoke here:
[https://en.wikipedia.org/wiki/File:Boeing_KC-135_J57_wet_tak...](https://en.wikipedia.org/wiki/File:Boeing_KC-135_J57_wet_takeoff.jpg)

They may be more efficient, but is there a pollution concern?

~~~
hausen
I'm no expert either, but according to
[https://en.wikipedia.org/wiki/Water_injection_(engine)](https://en.wikipedia.org/wiki/Water_injection_\(engine\)),
it actually reduces emissions.

~~~
qplex
In turbine aircraft engines that is not the case though.

Injecting water inside turbine engine causes fuel to go unburned, hence the
black smoke.

------
gambiting
People already complain about having to refill AdBlue for their Diesel engines
- and you realistically only have to do that every 6-12 months! MotorTrend did
a review of that M4 GTS and it worked its way through the 5L water tank very
quickly. So how often would the consumer need to refill the tank in a normal,
non-sports car?

~~~
Grishnakh
This system would probably be great for high-end BMW owners (not the regular
ones, just the really rich ones buying $100k models), who can be counted on to
get their car serviced at the dealership very frequently.

For regular Americans, it'd be a disaster. The tanks would run out and the
engines would fall back to their "limping" mode (the safe mode that doesn't
need water injection), which would likely have even worse fuel economy than if
they had just stuck with regular gas-powered engines without water injection.
This would cause the fleet fuel economy to fall greatly.

EVs can't come fast enough. At least almost every American seems to be able to
handle plugging in their phone regularly and keeping it charged up.

~~~
gambiting
Actually, if you watch the review of the M4, they very directly say that in
case the water runs out the engine performs exactly as the same, non water-
boosted engine. So this whole sentence about water-boosted engines that are
worse than non-water boosted ones when without water is garbage.

And evs are still not a solution for everyone. There doesn't seem to be any
good idea on how to own and charge one if you live in an apartment with a
shared parking lot or if you have to park on the street. You say that water-
boosting will work great for people who buy $100k cars, but at the moment, it
looks like EVs are only usable for people who can afford a house with a
driveway.

------
asimuvPR
People barely refill their windshield washer fluid. Asking them to refill a
tank with distilled water is a bit of a stretch. Not that I have anything
about water injection (I use it).

~~~
arethuza
"People barely refill their windshield washer fluid"

Where are you? I find that cars become pretty much undrivable within a very
short time if the windshield washer fluid runs out - particularly in winter.

NB I'm in Scotland.

~~~
fibonachos
California native here. What is this 'winter' you speak of?

In all seriousness, it takes about a month or more worth of dust buildup
before the view out of my windshield can be considered to have been obscured
in any way. Thankfully it rarely gets to that point since I usually clean my
windows when putting gas in my vehicle.

~~~
beamatronic
Not only that, but the windshield washer fluid you can buy in the Bay Area is
NOT the kind that doesn't freeze. Which could lead to a surprise if you head
up to Tahoe for skiing. You can buy the anti-freeze kind up there, but you are
supposed to "promise" not to use it back in the Bay Area.

~~~
fibonachos
I actually discovered this by accident one morning a couple of years ago. We
do get the occasional sub-freezing morning temperatures here during winter.
One such morning I used my windshield washers and wound up with a nice,
blinding sheet of ice on my windshield.

I had to pull into a parking lot and scrape it off with a debit card. Rather
dangerous situation for those of us who don't encounter real winter weather
often.

------
tricky
What keeps a reservoir filled up with distilled water from freezing solid in
cold weather? I bought a texas car off ebay and had it shipped up north. The
day it dipped below freezing was the first day I learned that texas windshield
washer fluid is mostly just colored water.

~~~
gambiting
Absolutely nothing. Which means that the distilled water tank would most
likely be heated. If you have Bi-Xenon headlamps with washers, they most
likely use heated jets already, so it's not an unusual technology in cars.

------
justsomedood
Nissan has a different take on solving this problem by having variable
compression on their new VC-T engines that were on here a few weeks ago. That
approach is nice because you don't have to fill any reservoirs and can still
get high compression ratios when not running under turbo boost thus increasing
efficiency. I really want to see where that one goes, and it is actually in a
production car I think this coming year.

------
rbanffy
Isn't the future electric?

~~~
ljf
It is - I'm sure of it, but anything we can do to improve the cars people buy
across the next 10 years here in the developed world, and likely 25 years in
the rest of the world. (Plus the X years people will be driving older cars
until petrol/diesel is properly taxed).

------
seansoutpost
Could the need to manually refill water periodically be replaced by a
condenser that constantly pulled ambient moisture out of the air? The total
amount of water they are talking about is not very much. This seems like it
could be solved without constant topping off.

~~~
minikites
I'm no physicist but wouldn't you lose a bunch of energy running a condenser?

~~~
MOARDONGZPLZ
I remember this, and it seems similar. it condenses water at ground level with
solar cells, refilling a water bottle:

[http://www.jamesdysonaward.org/projects/fontus-2/](http://www.jamesdysonaward.org/projects/fontus-2/)

~~~
hidroto
[https://www.youtube.com/watch?v=aPvXnmBIO7o](https://www.youtube.com/watch?v=aPvXnmBIO7o)

------
jagger27
Is it possible to replenish the water reservoir from the exhaust vapours?
Ideally it would never run out, if the water that gets injected comes out the
pipe anyway gets recycled plus what gets generated from combustion.

~~~
ljf
Here in the UK you could just do it from the rain that runs down the
windscreen. Maybe in the US you could run is from condensation from the AC? Or
I'd imagine filling it wouldn't be too hard or take too long. In the winter
here I probably fill my windscreen washer weekly or fortnightly, and it takes
30 seconds at most (pop bonnet, open the cap (drivers side near the top) pour
in 2lt of fluid, close cap, close bonnet - not dirty or difficult to do).

------
mgarfias
There is nothing new here. Lots of WW2 fighters had water (or water/methanol)
injection. All we’ve really learned since then is metallurgy and better
control systems (EFI).

------
6DM
Yes, people probably won't want to maintain a water reservoir, but performance
enthusiasts might.

~~~
lallysingh
That probably comes down to a question of consumption rate, capacity,
performance enhancement, and nagging by the car.

------
sunstone
This all seems so antiquated when compared with electric cars. They could be
flogging a dead horsepower here.

~~~
Eerie
Electric cars are SSDs, ICE cars are HDDs. See what I mean?

~~~
wcunning
I'm contemplating this metaphor, and it really works well. Basically, the
driving range is capacity and the acceleration/low end performance is access
speed. The only problem is that the kg/kJ stored is not accelerating at the
rate that bits/um^2 is accelerating, which makes the time to market domination
by the new technology less than stellar.

------
lightedman
And if not properly (re)designed, this is also a great way to hydrolock your
engine. Water doesn't compress, that's why it effectively increases your
compression ratio. That's also why your engine hydrolocks if it gets water-
logged. Water doesn't compress = pistons can't move.

~~~
dpark
You'd have to be a pretty incompetent automotive engineer to inject enough
water to cause hydrolocking.

Injecting water isn't done to "effectively increase your compression ratio".
If that were the goal, you'd just increase the stroke. Water injection cools
the engine, _allowing_ a higher compression ratio. If you injected enough
water to meaningfully increase the compression ratio on a 3L engine, you'd run
out of water in minutes anyway.

~~~
lightedman
"You'd have to be a pretty incompetent automotive engineer to inject enough
water to cause hydrolocking."

Ever hear of a shadetree mechanic? I've had to fix up after many of them. Two
hydrolocked engines, rusted out radiator (they put deionized water in the
reservoir, straight up) and plenty of failed turbo modifications.

I would not be surprised to see someone try doing this themselves and failing
miserably.

~~~
dpark
No, I've never heard of Bosch or BMW hiring shade tree mechanics to design
engines. I'm relatively confident that this isn't a real issue.

I think your concern about weekend mechanics is also unwarranted because most
of them aren't morons. The ones who are will be morons regardless and manage
to destroy cars regardless.

~~~
lightedman
"I think your concern about weekend mechanics is also unwarranted because most
of them aren't morons."

Go to an AutoX competition or two and I bet you'll be changing your mind on
that opinion very quickly.

