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Author Topic: Air-powered Peugeot  (Read 6396 times)
spaces
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« Reply #15 on: May 21, 2013, 02:16:17 PM »

You need to get involved,
                            To really understand the complex problems involved in working with either compressed gas or air.
   Even if you managed to build a working model you have to obtain too many different safety certs.Just imagine trying to get an M.O.T on such a vehicle over 4 years old.
  Spaces,I know you are one smart guy and I bet you gave the idea a lot of thought but one thing becomes very clear when working on such a vehicle.It gets heavy,very heavy,No matter how you do it the weight build up to a totally unacceptable level.I discovered this the hard way.Been there and worn the teashirt,
              Biff

Smart? Smart!  faint It would be a lot smarter to accept the status quo and not try and do things for myself - buying into the consumer economy and all that entails. Not throwing things away isn't considered smart by many - I wish I weren't practical, sometimes...  wackoold

I agree with you on the weight argument for a smaller vehicle, hydraulic stuff tends to suit bigger, especially if it's diy - matching hydraulic motors and pumps and accumulators efficiently is something which needs big resources. However, is PSA just finding work for engineers who would otherwise be kicking their heels, I wonder - http://www.psa-peugeot-citroen.com/en/inside-our-industrial-environment/innovation-and-rd/hybrid-air-an-innovative-full-hybrid-gasoline-system-article?

UPS has been running delivery vans with a hydraulic hybrid system for a few years, I believe Bosch is testing refuse trucks with their hydrostatic drive and energy regeneration and buses are using similar systems.
http://www.altairbusolutions.com/BUS-Series-Hydraulic-Hybrid-Drivetrain.aspx

I believe personal transport will eventually grow smaller and much lighter - by rights it ought to have a tiny petrol engined genny powering an electric motor. Larger vehicles would do well to make use of hydraulics and compressed gas energy storage rather than the massive battery cargo which would be required for an electric hybrid with KERS.

Biff, I'd love to hear of your foray into hydraulics and compressing gas - would you enlighten us?

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biff
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« Reply #16 on: May 21, 2013, 10:07:13 PM »

Years ago,
          I had this idea for running a bike on compressed air,I had the drive wheel.I had a miniture flyhte pump which could take the pressure up as high as I liked,10 bar would not have been a problem.I considered storing the air in the frame which would have been a little bigger than the ordinary bike but not any bigger than todays modern designs.The idea was simple,the pump for filling the tank was triggered by the brake lever and when you wanted to acelerate you just turned the handlebar grip.
          I got incredibly good co-operation with both the pump and motor,both were to be eventually spoked into the wheel like the modern Ebike hubs.
   There were serious heat issues around the connection to and from the compressed air tank.A bladder could have solved some of the problems but overall the main problem was still weight with the biggest problem getting a safety cert for the air vessel.That was the clincher the one thing that was way beyond reach.Sir clive was running around on a bike which was powered by a battery on the rear carrier which drove a little roller wheel directly onto the tyre.It actually worked and made fun of anything remotely connected to compressed air.
  One of the things about my Ebike is that it weighs only 22kgs and the battery weighs 2kgs of that so if my battery ever failed and it has never done so yet,I could easily pedal home just like an ordinary bike.Some things are not meant to be and a compressed air bike is one of them.Still it dont stop me thinking about it. facepalm
                                                 Biff
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spaces
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« Reply #17 on: May 22, 2013, 01:23:32 AM »

I love the thinking, shame it never made it - I'm not convinced there isn't some possibility lurking in there.

I'm now thinking hard about this - can't but come to the conclusion bike brakes are used very little compared with car brakes, since you are the one who supplies the energy in the first place. And at 20mph almost all the energy is used in overcoming air resistance with a normal bike - 80 or 90%. Even so, I have this vision of four old propane bottles strapped to a mountain bike instead of the pannier things I have, which not only store energy from the brakes but also the suspension motion. You could even pump 'em all up at the garage air pump to get you going... Mmm. Maybe the answer is reducing air drag. This would benefit a KERS, too.

Being a sailing boat sort of person as well as someone who has ridden a bike for many hundreds of miles into a steady headwind (a crosswind quickly becomes a headwind as your speed rises), I've also often wondered if with a wind at any more than, say, 70degrees to your direction of travel, you couldn't use a sail of some sort.

Reckon a small fairing would be as good as anything on a regular bike, but you never see them - why not? I do quite fancy a velocipede thingy, as shown on the lowtechmagazine site. Even without a leccy motor. Balls. Just seen the time - must have words with this cider maker.  Grin

http://www.notechmagazine.com/2010/05/belgian-recumbent-tricycles.html#more
http://www.lowtechmagazine.com/2012/10/electric-velomobiles.html
http://www.notechmagazine.com/2010/07/wind-powered-trikes.html
http://www.halfbakery.com/idea/Regenerative_20Brake_20Bike#1031850000
« Last Edit: May 22, 2013, 01:33:27 AM by spaces » Logged

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« Reply #18 on: May 22, 2013, 01:34:38 PM »

The side-wind providing forward-thrust concept is what you get with some of those extremely smart-looking carbon fibre bladed wheels on high-end time-trial bikes these days, it does work.
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« Reply #19 on: May 22, 2013, 02:08:25 PM »

The side-wind providing forward-thrust concept is what you get with some of those extremely smart-looking carbon fibre bladed wheels on high-end time-trial bikes these days, it does work.

Got a link to some article that explains how that works, please?
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« Reply #20 on: May 22, 2013, 02:23:21 PM »

Might need a cup of tea and a comfortable chair for this one, but this is the sort of thing.

http://flocycling.blogspot.de/2011/05/flo-cycling-wind-tunnel-results-and.html

You see it in full effect if you see cars with bikes mounted sideways - when they drive, the wheels spin forwards as the sideways air-flow turns the wheels.
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Mk1 ImmerSUN DHW diverter
4kW PowerVault Battery

Tesla Model 3 Long Range
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