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Engineers invent way for cars to harvest energy from bumps in the road

Enginasters to the fore!

The 255 million cars on the road in the United States account for 40 percent of the country's fuel consumption. Most of that fuel is wasted.

Lei Zuo, an associate professor of mechanical engineering in Virginia Tech's College of Engineering, may have a partial solution: harvesting energy from the car's suspension.

Zuo explained that only 10 to 16 percent of the fuel a car consumes is actually used to drive—that is, to overcome road resistance and air drag. Most of the rest is lost to heat and other inefficiencies.

With clever engineering, however, that deficit can be reduced.

Three major opportunities exist for recovering or generating energy while driving: the waste heat given off by the engine, the kinetic energy absorbed during braking, and the vibrational energy dampened by the shock absorbers, he said.

Such things bring me to tears. If any of my professors/tutors/lecturers had brought up such things I'd have laughed out loud because they would have been joking.

Alas, it seems that Zuo has no working understanding of:

  • how heat engines work

  • how the total road vehicle suspension works

  • conservation of energy

  • rolling resistance

  • road construction

  • the primary function of road vehicle braking

The simple solution to reducing the energy required to overcome rolling resistance is smoother, stiffer road surfaces. Such would immediately benefit all road users, reducing fuel consumption for all vehicles using such roads.

Re: Engineers invent way for cars to harvest energy from bumps in the road

I seem to recall the late James Hunt saying of tyre pressure that the harder the tyre the faster you roll. The harder the pressure, the more sensitive to bumps and thus the need for extra smooth road surface.
This would also mean that the suspension worked less.

Seems to me that this would be a better approach, to reduce the lost energy rather than converting it.

No doubt our intrepid researcher envisions the converse, roads converted from flat surfaces to one long sequence of sleeping policemen.

But maybe there are some nice grants in this research.

Re: Engineers invent way for cars to harvest energy from bumps in the road

I joyfully purchased a mountain bike a long time ago. It had "suspension" making the ride "smoother". I learned the first time I rode a distance further than the end of the block a simple, simple lesson. YOU DO NOT WANT suspension on your bike if you want to get somewhere efficiently. If you are going to go down a mountain, suspension is a wonderful thing. If you are pushing down on a pedal, that suspension absorbs part of your downward thrust.

The simple solution is don't have suspension...

Re: Engineers invent way for cars to harvest energy from bumps in the road

The simple solution is don't have suspension...

That's fine as long as you don't count the energy required to fix things broken by the rough ride.

Drive/braking torque also tends to produce suspension movement in conventional cars. And unconventional cars on drag strips.

Re: Engineers invent way for cars to harvest energy from bumps in the road

I'm considering buying a mountain bike with front suspension. A lot of the front suspension systems now feature a "lockup" mode, where they lock themselves rigid. You can use this whilst riding on the road, then switch back to a suspension system off road.

Obviously you are still carrying around excess weight of the suspension system whilst it is locked up, and therefore wasting energy, but it's a fashion thing!

Re: Engineers invent way for cars to harvest energy from bumps in the road

Narrower tyres would also help reduce rolling resistance. Indeed solid wheels would be even better.

As for the road surface the obvious answer would be to make all roads with an ice like surface although I would hazard a guess that some people might see a few negative attributes to such a suggestion, especially taking into account the need for globalisation of standards.

Clearly the imposition of the need for ice roads would negatively impact most of the so called "freedom of movement" rights in developing countries where the demands of the ice road creation and maintenance process would likely far exceed the national budget and power generation capabilities.

Which reminds me ....

I see Steorn is still around.