Tesla problems

Yeah, but if your input voltage was continuously variable via a large pedal attached to the floor, you might find that a buck-boost converter with discrete steps in its ratio would work just as well.

** Makes no sense.

Turbofan engines are highly efficient and their close relatives turboprop engines are even more so.

.... Phil

Perhaps it does make sense, if you consider that the energy pumped into the compressor is still present in the exhaust to be extracted again. So if 10-20% is true, there's a lot more energy circulating than driving the fan. Seems implausible, but it's possible.

I'm talking about the Civic HYBRID. I think you can STILL get a stick shift Civic, but NOT in the hybrid.

Right, and the manual got much better gas mileage.

Yes, but 100 Hp seems to be enough for modest-sized cars.

Jon

...

...

My error - The dates I mentioned are for the Civic Hybrid.

kevin

Hmm, sounds a lot like perpetual motion.

There's also a lot more energy circulating in a resonant tank than you can take off without killing the Q.

Jet turbines have to be spun really fast to even become self-sustaining, and even at operating speed they don't spool up and down very fast.

That's all good but you can't take the same energy out twice, as suggested.

On Wednesday, December 16, 2015 at 8:19:58 PM UTC-8, krw wrote: ...

Why not?

The energy doesn't know where it came from or how many times it has gone around.

The energy for the compressor has to be continually topped up with energy from the fuel because of losses but energy does recirculate.

A piston engine does similar - it takes energy to compress the inlet charge and some of that gets returned to the piston during the expansion stroke.

kevin

** There is a lot of spinning inertia involved and most of the thrust from turbofan engine arrives in the last 10% or so of the rpm range.

In any case, modern, high-bypass turbofan and turboprop engines operate at 50% to 60% thermal efficiency - meaning that most of the heat energy from combustion is made available as drive power to the fan or prop with a small residual thrust.

... Phil

CoE

Again, you sound like you're selling perpetual motion.

On Thursday, December 17, 2015 at 9:44:42 AM UTC-8, krw wrote: ...

...

All it is doing is extracting the energy from the exhaust gas (which is not as much as was put in) then putting it back into the compressor.

There is no violation of CoE or perpetual motion. At every stage there are losses and they require the energy input from the fuel.

It is no more perpetual motion than an LC circuit transferring energy back and forth between an inductor and a capacitor. To get sustain oscillations requires an amplifier with a power supply to make up the losses.

kevin

You implied there was by extracting the same energy twice. You even said it twice. ;-)

Here is what you said:

"Perhaps it does make sense, if you consider that the energy pumped into the compressor is still present in the exhaust to be extracted again."

Energy "extracted again" *does* violate CoE.

On Thursday, December 17, 2015 at 11:31:24 AM UTC-8, krw wrote: ...

What would you call it when you take energy out of the exhaust and convert to mechanical energy?

Some of this energy is then put back into the gas flow and the cycle repeats. There is no violation of CoE. It is just doing an energy conversion with the various losses both theoretical (Carnot) and practical.

I don't see the problem.

kevin

The first time or the second?

You're doing it again!

Bullshit! You can't take the same energy out twice, without violating CoE.

Obviously. You're a prime candidate for the next free energy scam.

this is a semantics problem

you can take a unit of energy out of the FUEL only once

that unit of energy can then circulate among different parts of the machine

it can come out of one part of the machine and go back into another

and then come out again

but finally go into the load (or waste) only once

so any unit of energy is generated once and consumed once but it can take any convoluted path in between

Mark

You can only use (convert) it once, also.

As long as it's doing no work (though it is, in fact).

As long as it's doing work once.

As long as it didn't do anything while there (it lost energy).

It can only do work, once. Anything you do between converting fuel to heat and converting that heat into work simply loses energy (heat).

Any dicking around simply loses energy.

Work is not the same as losses. Pushing against a spring is doing work and the energy is recoverable by letting the spring push back to restore to it's original position. Compressing a gas is not so much different or spinning a blade. Work is done to transfer energy, not necessarily losing it as waste heat.

--

Rick