I suggest using this on down hill segments only (no matter how small of slope), any energy extracted from the vehicle forward motion will reduce any braking (engine or pedal induced) that might be applied to maintain speed. Since the repeated rise fall pattern will increase suspension movement, might as well consider the extractable energy onboard, too, rather than bleed that off as just heat. -- -Chris
On August 27, 2016 4:02:44 PM CDT, via EV <[email protected]> wrote: >First I have to explain that I am an Agile coach. My job is to teach >companies and their people to treat EVERYTHING as an unproven >hypothesis. Then the work is to either prove or disprove that >hypothesis through conducting experiments. The experiments are to be as >simple and as inexpensive as possible to yield valid results. The >result of each experiment yields new data, and a new set of hypotheses. >New experiments are then set up to either prove or disprove these. The >process is repeated as needed until a clear strategic path forward is >identified. Guessing and assumptions are no longer allowed to be used >to determine decisions because they stifle innovation. > >Therefore, in this case I cannot dismiss the piezo approach until >sufficient experiments are run that prove or disprove whether it >represents a viable approach. > >> The movement of the Piezo elements is not >> instantaneous, in fact they will generate the most energy when they >only yield slowly to the force, such that the largest possible force >over the largest possible time can act on them. > >While this is optimal, it it a requirement? In other words, would the >Piezo element still generate energy of it were forced to act more >quickly? In other words, could there be an optimum reaction response >that balances the energy generated while reducing the "uphill effect"? >Just wondering... > >Also, wouldn't the speed of the vehicle significantly impact your >example? The ratio to time to travel the slab relative to the response >time of the Piezo would see to differ drastically between 15 mph rush >hour traffic and 70 mph off peak traffic flow. If the response time >were forced tom e a constant, some less that ideal response time would >have to be selected based on average speed or some traffic flow/speed >optimization. > >What about only placing the piezo elements at the far end of the >concrete slab? And adjust the static angle of the slab to minimize "the >uphill effect"? Each slab could have the far end higher than the near >end yet the total would actually be level or even a very slight >downhill. Of course, driving the wrong direction would be a very >unpleasant experience. The city just ground down an entire road near my >house because the soil expansion actually produced this effect. I >avoided driving down that section until they fixed it because the ride >was so unpleasant. > >The Piezo I saw demonstrated only had a very small range of motion, say >less that 1/16" and could react nearly instantaneously by only >compressing it between your fingers while generating enough energy to >light a led. > >Put a set if these at the far end supporting a 30' slab of concrete. >The rise would be 1/16" over 30'. That comes out to something like >0.00017 degrees of rise. Let's say a 4000 lb vehicle is on that slab. >If the slab were perfectly level, all 4000 lbs would result in a pure >downward force to deflect the Piezo element with no additional rolling >resistance due to a rise. The force vector changes with the 0.00017 >degree rise. Now 3999 lbs of force are available to deflect the Piezo >element and 1 lb of force is wasted due to the rise. The difference in >force vectors is more than 3 orders of magnitude! Off the top of my >head, 3 orders of magnitude seems insignificant enough to dismiss as >"noise". I would guess that friction in general and the rolling >resistance of the tires are larger that that. I wonder what the drag of >disk brakes is? I would be willing to wager that I could attach a rope >to that vehicle and manually pull it against that load for an entire >day. Again, experimen >ts would need to be run to prove or disprove this, but being able to >use 3999 lbs to generate energy at the cost of only 1 lb seems like a >pretty good trade off to me. Obviously not perpetual or free energy but >awfully close. At least enough to warrant investigation through >experimentation before dismissing the idea completely. >_______________________________________________ >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >http://lists.evdl.org/listinfo.cgi/ev-evdl.org >Read EVAngel's EV News at http://evdl.org/evln/ >Please discuss EV drag racing at NEDRA >(http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
