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One of the issues with using Gas turbines in cars is that they require a constant flow of fuel to keep running. This leads to fuel consumption in a typical car being up to 8 time higher than an IC engine.
I propose the integration of a flywheel Energy storage unit into the rotor of the turbine/compressor.
Then the turbine fuel supply could be shut off when low or no power is needed(much like a modern gas hybrid vehicle regulates the engine) When power is needed the fuel supply is resumed and power is supplied. This allows for extended idling and coasting with no use of fuel thus recovering a great deal of the wasted energy.
This system has the added benefit of near instantaneous power boost by combining the flywheel output and the turbine exhaust output at the same time(see Chrysler Turbine link).
A Hybrid Flywheel Car
http://www.accessto...rchive/s76a3958.htm
A brief discussion of the subject. [drememynd, Aug 28 2007]
Reinventing the Wheel
http://findarticles..._n8_v17/ai_18471043
A 1996 Discover magazine article. [drememynd, Aug 28 2007]
Flywheel Hybrid Promises a Possible 250 MPG
http://www.greencar...dquoextremerdq.html
This is about one company which is actually making a prototype and trying to market the technology. [drememynd, Aug 28 2007]
Chrysler Turbine
http://conceptengin...ceptengine/id4.html
See the diagram, then incorporate flywheel into the compressor/turbine shaft, so that power can be drawn from turbine or from flywheel. [jhomrighaus, Aug 28 2007]
[link]
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This is a great idea, but has been in discussion for years. The idea, I believe, has already even been baked in experimental models. The main drawback to production is that the technology is so different from what we are currently using that the initial expense to mass produce the engine is immense. See Links. |
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Actually [Drememynd] i am well aware of flywheel hybrids that you are describing. |
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THIS IDEA IS NOT THE SAME AS THAT DESCRIBED IN THE LINKS! |
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The difference with this idea is that I want to incorporate the Turbine into the flywheel itself(or flywheel into turbine). The Turbine will spin up to 40000 RPMs or so and then the mass of the rotor will maintain the RPMS during periods without load. |
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Put in simplest terms in this idea the Flywheel IS the Turbine. |
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Sounds practical. Since I'd assume the turbine would create a lot of waste heat, you could run a hybrid system off of it and increase the efficiency even more (or it would at least allow you to run a smaller turbine). |
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Im thinking this would be a smaller size turbine then you might otherwise require, There are a number of reclaimer type systems that can recover a large amount of the heat to increase efficiency of the turbine. |
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See Link for a diagram of a Chrysler Turbine, the goal is to incorporate a flywheel into the compressor/Turbine portion of the engine that can be coupled to the tranny for additional power. |
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I've been thinking of a much more complex hybrid turbine and flywheel powered drive train for at least a few weeks now. I just can't determine the best mechanical linkage between the engine, the flywheel, and the wheels. |
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I see your idea as basically a turbine engine with added weight to it, to allow the fuel to be cut off part of the time. Your engine would take longer to start than a regular turbine. |
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That is true it would take longer to start, but even a simple electric starter would be able to provide sufficient power to get things moving. |
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The Chrylser link shows some images of the way the engine linkage was setup. I suppose it may be a challenge to incorporate the flywheel as a direct power draw source. |
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What type of transmission do you think you might use for this engine? |
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I think flywheels are much better suited to turbine engines than piston engines because they spin much faster which means they can store more energy. And since they take longer to get up to speed, the flywheel could compensate for that, and provide bursts of torque. |
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Considering the speed of rotation of a gas turbine engine, adding a bunch of weight is going to fry the bearings or make them really expensive. |
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I'm not sure that's really the case. What frys bearings is vibration and heat(lack of lubrication). The mass of the spinning object is a tertiary concern I think(within reason) |
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Turbines are dynamically and statically balanced and so experience almost no vibration. The addition of peripheral mass to the system does not change the balance of the system, as long as the bearings are designed for the rotor mass the bearing technology is more than sufficient to the job. |
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[BJS] The Chrysler link only touches on the transmission issue but I believe they utilized a variable secondary rotor(unclear if is moving vane or venting for control) that allowed for infinite control of the RPMs(through a suitable reducer) Initially a down geared CVT would work great but I would guess that internal gear reduction would permit an axial transmission of power from either the secondary turbine or the flywheel turbine to a conventional automotive drive-train(allowing for direct bolt on or conversion of existing designs. |
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Something on the order of say a 2:1 or 3:1 to the power coupling gear then another 2:1 or 3:1 on the output shaft would drop the RPM max in to around 6500 rpms (right in line with modern engines) Available torque would be significant(I would guess well over the 400ftlbs sited in the link if the flywheel mass could be coupled as well) Note that torque is cited at 0rpms so torque curve would be more like an electric motor I would guess than a normal ICE. |
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The Chrysler car used a TorqueFlite automatic transmission. |
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Yes but they gear reduced the turbine output to match the normal ICE output RPMs. |
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If you want the system to idle (with no fuel) for any length of time, you would need to 'feather' the compressor and turbine blades, otherwise your flywheel is trying to drive your compressor, which would use up the stored energy quick smart. |
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Unless this was used with [jhomrighaus]'s other idea for a turbine using a piston engine as an air compressor. Then all you'd need is a clutch. |
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I've already thought about that matter... |
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Myself, I'm envisioning a variation on the hamster wheel, powered by flies. |
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You could just make a turbine-electric hybrid. Charge a battery bank with the turbine and turn the wheels with electric motors. |
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Plug it in overnight to charge the battery. The car runs on the battery and when it discharges to a certain level the turbine kicks in. The speed of the turbine being the average speed of the car, generating less energy than it takes to accelerate the car but continues to charge the batteries when you decelerate. |
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That idea has already been proposed on this site. |
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[bigsleep]: that's basicly what the Prius does but driving the wheels mechanically means the engine has to speed up and slow down with the wheels. Piston and especialy gas turbine engines are most efficent when running at a constant speed. |
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