R.A.T. (Ram Air Turbine) for Battery charging

[FlipOne]

Not sure if this is in the right section or not but here goes. When I was in the Air Force there was an auxiliary system that we use for hydraulics as well as power generation called a rat or ram air turbine there's a company that makes a low rpm alternator/ wind turbine it puts out 12 V I just 6 mile an hour wind so has anyone thought about using one of these especially on a trike for charging the batteries I want to say the thing puts out like it's like 40 V and 10 A at 20 miles an hour
http://www.windbluepower.com/Permanent_Magnet_Alternator_Wind_Blue_Low_Wind_p/dc-540.htm

 

[Chalo]

First, that thing takes a pretty big set of blades to deliver its rated power. I doubt you could find room for them on a personal vehicle.

Second, the energy comes from drag on your motion, fundamentally. That works directly against the whole point of a vehicle. You'll incur much more of an energy penalty as drag than whatever energy you could recover while underway. That's the case even with a jet's ram air turbine, but a jet has a huge surplus of energy to work with and the RAT gives it critical system redundancy.

If you had a small lightweight windmill on your trike that you could raise when it was parked, and it didn't cause the trike to be blown over, then that might be of some value in a windy location.

 

[FlipOne]

Ah good point I didn't think about the exsesiv* drag. I was thinking about putting like 6" blades on it or mounting it to the trailer I use to haul stuff

 

[spinningmagnets]

When I was studying wind turbines for generating electricity, I learned a bit about the Betz limit (sp?).

It's the max amount of air that can flow through a turbine to generate electricity. If you add too many blades, or make a few blades wider...both increase the "solidity" of the turbine. That's a fancy way of saying that air starts to flow around the turbine, instead of through it.

So, you make a portable turbine as big as you dare, while adjusting the number of blades and the blade width, and you arrive at a design that produces the maximum watts you can harvest from the bikes forward motion. Since you are going to go forwards anyways, it may seem like free energy just flowing past you, and you have only reach out to get some.

When a wind turbine at a farm is not connected to a load, it seems to spin freely, and very fast. But once tbe farms storage battery gets low enough that it is connected to the battery to charge it, the turbine will slow down, due to the resistance of charging the battery. As stated in a post above, as soon as you deploy the turbine from a bicycle, you will immediately feel wind resistance. The bikes motor will draw more amps to maintain speed, than the turbine could possibly generate.

 

[nutnspecial]

Unless using the turbine for downhill additional brake regen, what might be cool is seeing how much power and added fun could be had when in conjunction with a wingsuit. Usable for less fall, more control . . .? https://www.youtube.com/watch?v=rnvvsjstveM

I noticed the title turbine, and wanted to mention the 'tesla turbine' I'd been checking out lately. http://auto.howstuffworks.com/tesla-turbine4.htm page 6 and 7
http://www.instructables.com/id/Build-a-15,000-rpm-Tesla-Turbine-using-hard-drive-/
Interestingly enough, 100+ yrs later it could be considered for replacement of some reciprocating ice engines. I've yet to see it setup with fuel, but the mini versions are neat running from just compressed air. Could be handy for someone somewhere.

 

[maydaverave]

What about using a small jet engine to spin said turbine to recharge batteries?

 

[Chalo]

In that case, why not use a more efficient, cleaner running small piston engine to drive the wheels directly?

Because it's disgusting, that's why.

 

[amberwolf]

See this thread (among dozens of others):
https://endless-sphere.com/forums/viewtopic.php?f=1&t=76337
for many explanations of why it won't do what you want.

 

[FlipOne]

Thanks for the informative replys

 

[tiny_n_terrible]

Unless using the turbine for downhill additional brake regen, what might be cool is seeing how much power and added fun could be had when in conjunction with a wingsuit. Usable for less fall, more control . . .? https://www.youtube.com/watch?v=rnvvsjstveM

I noticed the title turbine, and wanted to mention the 'tesla turbine' I'd been checking out lately. http://auto.howstuffworks.com/tesla-turbine4.htm page 6 and 7
http://www.instructables.com/id/Build-a-15,000-rpm-Tesla-Turbine-using-hard-drive-/
Interestingly enough, 100+ yrs later it could be considered for replacement of some reciprocating ice engines. I've yet to see it setup with fuel, but the mini versions are neat running from just compressed air. Could be handy for someone somewhere.

Tesla and others could Not find a material that would work for the turbine blades. Not even single crystal modern turbine blades can withstand the forces involved.
Maybe some day!

Couple Tesla'a turbine with his serpentine inlet valve running on solar or catalyticly cracked water . Now your talking about clean power.

 

[Chalo]

I built an LP gas fueled Tesla turbine at one of my tech jobs, for a stationary power application. We used nickel alloy for the rotor. It worked fine; it just wasn't terribly efficient.

There's nothing very outstanding about a Tesla turbine. It's chief advantage is that it delivers meaningful power at a much lower shaft speed than a traditional gas turbine. In the application I was building it for, that meant being able to couple the rotor directly to the motor/generator shaft without a reduction gear.

 

[maydaverave]

Unless using the turbine for downhill additional brake regen, what might be cool is seeing how much power and added fun could be had when in conjunction with a wingsuit. Usable for less fall, more control . . .? https://www.youtube.com/watch?v=rnvvsjstveM

I noticed the title turbine, and wanted to mention the 'tesla turbine' I'd been checking out lately. http://auto.howstuffworks.com/tesla-turbine4.htm page 6 and 7
http://www.instructables.com/id/Build-a-15,000-rpm-Tesla-Turbine-using-hard-drive-/
Interestingly enough, 100+ yrs later it could be considered for replacement of some reciprocating ice engines. I've yet to see it setup with fuel, but the mini versions are neat running from just compressed air. Could be handy for someone somewhere.

Tesla and others could Not find a material that would work for the turbine blades. Not even single crystal modern turbine blades can withstand the forces involved.
Maybe some day!

Couple Tesla'a turbine with his serpentine inlet valve running on solar or catalyticly cracked water . Now your talking about clean power.

That Tesla turbine is cool. Time to start the compressed air power vehicle debate again?

 

[tiny_n_terrible]

I built an LP gas fueled Tesla turbine at one of my tech jobs, for a stationary power application. We used nickel alloy for the rotor. It worked fine; it just wasn't terribly efficient.

There's nothing very outstanding about a Tesla turbine. It's chief advantage is that it delivers meaningful power at a much lower shaft speed than a traditional gas turbine. In the application I was building it for, that meant being able to couple the rotor directly to the motor/generator shaft without a reduction gear.

Chalo I love your helmet.
I think we are talking about two separate things.
A Tesla turbine as designed by Mr Tesla used viscosity to impart force to the many parallel thin rotors. The working medium entered from the outside edge of the rotor and was exhausted to the center of the device.
There is no way it could be used direct drive but needed to be geared down.

Perhaps if I am in error that is why no one has built a working model as I believe my version is correct.

 

[Chalo]

That's exactly the kind of turbine I'm talking about. I know this because I built one.

Yes, it runs slower than a vane-and-stator axial flow turbine or a turbocharger type impeller turbine. Thus it may require high temperature materials, e.g. nickel alloy, but it does not require inordinately strong materials.

The rotor on the one I built was less than a foot in diameter and it ran at between 5 and 10k RPM if I remember correctly.

 

[dogman dan]

In some places, you could plausibly carry a very small wind turbine, and charge while you parked. But in general, carrying about 100w worth of solar panel seems to work best. And you do see people carry more than that.

I just find that carrying 60 miles range worth of battery works well, about 48v 30 ah. 25 pounds or so.

 

[maydaverave]

In some places, you could plausibly carry a very small wind turbine, and charge while you parked. But in general, carrying about 100w worth of solar panel seems to work best. And you do see people carry more than that.

I just find that carrying 60 miles range worth of battery works well, about 48v 30 ah. 25 pounds or so.

What speed do you cruise at?

 

[dogman dan]

18mph is a good cruise speed for me, for getting that 60 mile range. That range can include over a large mountain pass too, or lots of rolling hills. It's slow, but above 20 mph you tend to spend the whole ride just looking for the next debris in the road. 15-20 mph, you then have lots of time to look around, seeing for the first time a road you looked at hundreds of times at 60 mph.

But if I need less, I can of course cruise much faster.