MIT students adapt regenerative braking principles to shock absorbers

[Fern]

Originally posted by: TheSnowman
You mean there are cars which run off partially off electricity, WTF?

Cars?

They're also talking about military Humvees and Walmat's semi's (trucks).

I was unaware that those were hybrids?

Fern

 

[Moonbeam]

Originally posted by: Fern

Originally posted by: CallMeJoe

Originally posted by: Fern

The regenerative shock absorbers developed by the students use a hydraulics system to smooth the ride and capture the lost energy by forcing hydraulic fluid through a turbine that generates electrical power.

It's not clear to me how using the shocks to generate electricity increase gas mileage, unless they're claiming it somehow reduces the load from the alternator. I.e., the electricity generated from the shocks means less horsepower used to turn the alternator, resulting in better gas mileage.
I wasn't aware the alternator had such a large impact on gas mileage?

Fern

They're using the system to recharge the battery pack on a hybrid vehicle...

That's not what the article says, at least the way I read it.

Looks like they're saying all vehicles.

I still think my alternator question is valid...

Fern

As I stated above, the alternator in a car uses 1 to 2 horse power, a larger vehicle and larger alternator will use more or about one horsepower per 12 amps.

From the web:

Amps x Volts = Watts
Watts / 745.7 (one HP) = Electrical HP Produced by the Alternator
HP x 15% Efficiency Loss = HP Loss
HP + HP Loss = Total HP Used

57A x 14.9V = 849.3 Watts
849.3 Watts / 745.7 = 1.14 HP
1.14 HP x 15% = 0.17 HP
1.14 + 0.17 = 1.31 HP Total

 

[Doc Savage Fan]

Originally posted by: Moonbeam

Originally posted by: Fern

Originally posted by: CallMeJoe

Originally posted by: Fern

The regenerative shock absorbers developed by the students use a hydraulics system to smooth the ride and capture the lost energy by forcing hydraulic fluid through a turbine that generates electrical power.

It's not clear to me how using the shocks to generate electricity increase gas mileage, unless they're claiming it somehow reduces the load from the alternator. I.e., the electricity generated from the shocks means less horsepower used to turn the alternator, resulting in better gas mileage.
I wasn't aware the alternator had such a large impact on gas mileage?

Fern

They're using the system to recharge the battery pack on a hybrid vehicle...

That's not what the article says, at least the way I read it.

Looks like they're saying all vehicles.

I still think my alternator question is valid...

Fern

As I stated above, the alternator in a car uses 1 to 2 horse power, a larger vehicle and larger alternator will use more or about one horsepower per 12 amps.

From the web:

Amps x Volts = Watts
Watts / 745.7 (one HP) = Electrical HP Produced by the Alternator
HP x 15% Efficiency Loss = HP Loss
HP + HP Loss = Total HP Used

57A x 14.9V = 849.3 Watts
849.3 Watts / 745.7 = 1.14 HP
1.14 HP x 15% = 0.17 HP
1.14 + 0.17 = 1.31 HP Total

Damn Moonbeam...I've seen a new side to you...clear and rational discourse...I'm impressed! Hope to see more.

 

[Harvey]

Originally posted by: CADsortaGUY

I wept while reading this thread.... one reason is because I nodded in agreement with Harvey, and the other was because I hit myself too hard due face-palm...

BUAHAHahahahaha!!! While CAD and I disagree about a lot of things, we both know we're all subject to the laws of physics. We may have to band together and report those who still don't get it to the Newtonian police. :laugh:

 

[Fern]

Originally posted by: Moonbeam

Originally posted by: Fern
-snip-

As I stated above, the alternator in a car uses 1 to 2 horse power, a larger vehicle and larger alternator will use more or about one horsepower per 12 amps.

From the web:

Amps x Volts = Watts
Watts / 745.7 (one HP) = Electrical HP Produced by the Alternator
HP x 15% Efficiency Loss = HP Loss
HP + HP Loss = Total HP Used

57A x 14.9V = 849.3 Watts
849.3 Watts / 745.7 = 1.14 HP
1.14 HP x 15% = 0.17 HP
1.14 + 0.17 = 1.31 HP Total

Thanks,

Yes, I saw that and other similar type info back when I first posted my alternator question several days ago.

My 'real question' was always about the claimed mileage savings of 10%; that seems too high to me based on your formula and others I've seen if the savings is resulting from the decreased dependance on the alternator. Even if the need for the alternator was completely obviated by the new shocks, I still don't see 10%; I have trouble accepting that an alternator requires 10% of our gas consumption.

Fern

 

[Moonbeam]

Originally posted by: Fern

Originally posted by: Moonbeam

Originally posted by: Fern
-snip-

As I stated above, the alternator in a car uses 1 to 2 horse power, a larger vehicle and larger alternator will use more or about one horsepower per 12 amps.

From the web:

Amps x Volts = Watts
Watts / 745.7 (one HP) = Electrical HP Produced by the Alternator
HP x 15% Efficiency Loss = HP Loss
HP + HP Loss = Total HP Used

57A x 14.9V = 849.3 Watts
849.3 Watts / 745.7 = 1.14 HP
1.14 HP x 15% = 0.17 HP
1.14 + 0.17 = 1.31 HP Total

Thanks,

Yes, I saw that and other similar type info back when I first posted my alternator question several days ago.

My 'real question' was always about the claimed mileage savings of 10%; that seems too high to me based on your formula and others I've seen if the savings is resulting from the decreased dependance on the alternator. Even if the need for the alternator was completely obviated by the new shocks, I still don't see 10%; I have trouble accepting that an alternator requires 10% of our gas consumption.

Fern

From the web:

One Kilowatt = 1.33 horsepower.
.75 Kilowatt = 1 horsepower. Both are units measuring power. most small economy cars are around a 100 hp (75 kW). cruising down the highway may only take 20 hp (15kW).
------------

So the key is that you only use 20 hp to drive down the highway, not the total hp the car is capable of. Therefore 2 hp would be 10% of that.

 

[PaperclipGod]

Originally posted by: CADsortaGUY

So where is the issue then? I don't see why "bandwagon-jumpers" are getting called out when you were the one confused.

I was confused about how the system was engineered. Since you read the thread, you should see that no one was saying "dued OF COURSE you can create energy from nothing!1" or explaining why some property I was basing my argument on was incorrect.

I'm not saying my knowledge of physics is uber, or even decent, it's not. Hell, I'm embarrassed at my own ignorance when it comes to the sciences... but I also find it ironic that as lowly as my knowledge of physics is, my (AFAIK) correct interpretation of the principles involved was rebuked with "LOL LRN2FYZUCKS NOOB." If i'm ashamed of my physics education, but at least have a rudimentary understanding of classical mechanics, what does that say about the folks who are apparently both ignorant of physics and arrogantly ignorant of their own ignorance?!

It's like laughing at Isaac Newton for not understanding how an internal combustion engine works. The guy knows classical physics, but he's not a mechanical engineer with 200 years of relevant experience, so it'd be kind of dumb to assume he'd immediately recognize how to apply his knowledge of physics to the engineering of an engine.

 

[CADsortaGUY]

Originally posted by: PaperclipGod

Originally posted by: CADsortaGUY

So where is the issue then? I don't see why "bandwagon-jumpers" are getting called out when you were the one confused.

I was confused about how the system was engineered. Since you read the thread, you should see that no one was saying "dued OF COURSE you can create energy from nothing!1" or explaining why some property I was basing my argument on was incorrect.

I'm not saying my knowledge of physics is uber, or even decent, it's not. Hell, I'm embarrassed at my own ignorance when it comes to the sciences... but I also find it ironic that as lowly as my knowledge of physics is, my (AFAIK) correct interpretation of the principles involved was rebuked with "LOL LRN2FYZUCKS NOOB." If i'm ashamed of my physics education, but at least have a rudimentary understanding of classical mechanics, what does that say about the folks who are apparently both ignorant of physics and arrogantly ignorant of their own ignorance?!

It's like laughing at Isaac Newton for not understanding how an internal combustion engine works. The guy knows classical physics, but he's not a mechanical engineer with 200 years of relevant experience, so it'd be kind of dumb to assume he'd immediately recognize how to apply his knowledge of physics to the engineering of an engine.

Ah, you were ranting at the people who didn't post anything constructive - just laughing. Got it.