Mitsubishi Outlander PHEV Forum

It is currently Fri Nov 24, 2017 6:05 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 33 posts ]  Go to page Previous  1, 2, 3, 4
Author Message
 Post subject: Re: Effect of gradient on fuel consumption...
PostPosted: Wed Jan 20, 2016 4:50 am 
Offline

Joined: Fri Jul 18, 2014 4:46 am
Posts: 2789
Sunder wrote:
My head is now spinning with everyone arguing in every direction. So where does everyone think the missing 15% went? (10% expected compared to 25% actual).

I'm arguing the 15% is the "meaningless" dips and rises. Of any kind of energy conversion, it would most likely be the most efficient - because it's a straight kinetic to kinetic energy conversion. You might gain a kilometer an hour or two, and then lose it on the next micro incline.

Even in Alpine driving, in a perfect ideal situation, you would double your power going up, and spend no power going down. But only in a perfect situation. If you start hitting (non-regen) brakes, you'd lose some of that stored potential energy to heat.

Meh. Way too many variables to track who is arguing what.

Let's just say 25% doesn't surprise me. If it surprises you, that's okay.


Well, let's not get too hung up on exact percentages - I didn't set out to conduct a scientific experiment and simply noticed some figures that surprised me part way through my journey. There would be a variety of other factors to eliminate before we get to a definitive figure. Anko's calculation of 10% is a bit of a "back-of-a-fag-packet" figure - useful to put it into context but not to be considered definitive either.


Top
 Profile  
 
 Post subject: Re: Effect of gradient on fuel consumption...
PostPosted: Wed Jan 20, 2016 5:11 am 
Offline

Joined: Mon Dec 01, 2014 11:30 am
Posts: 2598
Location: Netherlands, Utrecht area
Sunder wrote:
I'm arguing the 15% is the "meaningless" dips and rises. Of any kind of energy conversion, it would most likely be the most efficient - because it's a straight kinetic to kinetic energy conversion. You might gain a kilometer an hour or two, and then lose it on the next micro incline.
Although I doubt it, it might explain 15% difference between a trip in the Netherlands and a trip in a more hilly environment, but how can it explain 15% difference between the first half and the second half of Maby's trip? As both half of the trips most likely have these "meaningless" dips and rises.


Top
 Profile  
 
 Post subject: Re: Effect of gradient on fuel consumption...
PostPosted: Wed Jan 20, 2016 4:16 pm 
Offline

Joined: Fri Nov 13, 2015 3:05 am
Posts: 82
maby wrote:
Anko's calculation of 10% is a bit of a "back-of-a-fag-packet" figure - useful to put it into context but not to be considered definitive either.


Yeah. I would have considered it a textbook answer, not a real world answer. The same way that in a textbook a perfectly elastic ball can bounce forever :)

Anyway. All fascinating, and all relevant. I have been helping a guy on an electric bike forum build a bike that can go 45km/h on the flats, but will not melt the motor on a 15% gradient hill. Not difficult if you can strap a large multi-kilowatt motor to your bike, but much more challenging when you want a stealthy micro motor.

We've been working through the impact of different winds, different stator sizes and lamination thicknesses, different voltages and different methods of commutation. Again, so many things to wrap your head around.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 33 posts ]  Go to page Previous  1, 2, 3, 4

All times are UTC - 8 hours [ DST ]


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
© Mitsubishi Outlander PHEV Forum - part of the MyElectricCarForums.com Group