ElectricMotorcycleForum.com

Tech => Tech Help => Topic started by: Richard230 on November 27, 2016, 04:44:15 AM

Title: Aerodynamic & rolling resistance calulator
Post by: Richard230 on November 27, 2016, 04:44:15 AM
Someone might find this site useful - or at least interesting. Apparently, you can plug in various values for your vehicle (if you can figure out what they are) and it will calculate its rolling resistance and power needed to achieve various speeds: http://ecomodder.com/forum/tool-aero-rolling-resistance.php (http://ecomodder.com/forum/tool-aero-rolling-resistance.php)
Title: Re: Aerodynamic & rolling resistance calulator
Post by: BrianTRice@gmail.com on November 27, 2016, 09:04:37 AM
Yes, and I've managed to adapt it into a spreadsheet for calculating optimal travel strategies for Zeros. I made sure to duplicate the results that DoctorBass got, although shuffling between metric and imperial units was trickier than I expected!

I'm hoping to make a simple interactive visual webapp that illustrates how it all works, that is, how charging upgrades or windspeed or aerodynamics each add up.

There's definitely some kind of lesson about an airspeed limit beyond which going faster makes you go slower because you incur more charging time than you save by going faster while traveling! I'm just trying to pin it down so I don't make a BS claim.
Title: Re: Aerodynamic & rolling resistance calulator
Post by: Richard230 on November 27, 2016, 08:44:32 PM
I might add that that link was sent to me by a friend who owns a motor home.   :o
Title: Re: Aerodynamic & rolling resistance calulator
Post by: ctrlburn on November 29, 2016, 12:41:43 PM
This is the type of calculation I expected in the "EV Range" or "PlugShare" smartphone app for routing.

I feel shouldn't have to pick "AVOID HIGHWAYS" when my range can make it between the charging locations at highway speeds.

HOWEVER when stretching the range - I should find myself on "B" roads.

Programs should do things better then I could guess and round - but these EV routing Applications are missing this key calculation.

So What numbers are best plugged in to get Zero like results from:
http://ecomodder.com/forum/tool-aero-rolling-resistance.php (http://ecomodder.com/forum/tool-aero-rolling-resistance.php)

Because I think "EV Range" would add Zeros to the "Favorite Vehicle" if I sent him the drag information.
Title: Re: Aerodynamic & rolling resistance calulator
Post by: BrianTRice@gmail.com on November 29, 2016, 04:04:29 PM
This is the type of calculation I expected in the "EV Range" or "PlugShare" smartphone app for routing.

I feel shouldn't have to pick "AVOID HIGHWAYS" when my range can make it between the charging locations at highway speeds.

HOWEVER when stretching the range - I should find myself on "B" roads.

Programs should do things better then I could guess and round - but these EV routing Applications are missing this key calculation.

So What numbers are best plugged in to get Zero like results from:
http://ecomodder.com/forum/tool-aero-rolling-resistance.php (http://ecomodder.com/forum/tool-aero-rolling-resistance.php)

Because I think "EV Range" would add Zeros to the "Favorite Vehicle" if I sent him the drag information.

I used these to replicate DoctorBass' and ProtoMech's figures (http://electricmotorcycleforum.com/boards/index.php?topic=1929.msg6557#msg6557 (http://electricmotorcycleforum.com/boards/index.php?topic=1929.msg6557#msg6557)):

   Empulse R   Zero S
Constant Load   0.1   0.1
Crr   0.03   0.02
Cd   0.65   0.65
Dry Weight   500   400
Rider/Extra Weight   120   120
Weight   620   520
Battery (kWh)   8   11.4
Aero Area (m^2)   0.7   0.8
CdA   0.455   0.52
Parasitic Load (kW)   0.1   0.1
Engine Efficiency   0.92   0.90
Drivetrain Efficiency   0.85   0.94
Title: Re: Aerodynamic & rolling resistance calulator
Post by: BrianTRice@gmail.com on November 29, 2016, 04:06:53 PM
This is the type of calculation I expected in the "EV Range" or "PlugShare" smartphone app for routing.

I feel shouldn't have to pick "AVOID HIGHWAYS" when my range can make it between the charging locations at highway speeds.

HOWEVER when stretching the range - I should find myself on "B" roads.

Programs should do things better then I could guess and round - but these EV routing Applications are missing this key calculation.

So What numbers are best plugged in to get Zero like results from:
http://ecomodder.com/forum/tool-aero-rolling-resistance.php (http://ecomodder.com/forum/tool-aero-rolling-resistance.php)

Because I think "EV Range" would add Zeros to the "Favorite Vehicle" if I sent him the drag information.

FWIW there is a promising app in rough beta that I'm trying out: http://www.evtripn.com/ (http://www.evtripn.com/)

I need to write up my feature/UI suggestions for them to chew on.
Title: Re: Aerodynamic & rolling resistance calulator
Post by: ctrlburn on November 29, 2016, 09:16:40 PM
I like EVtripn - it is definitely getting closer. $0.99 well spent.

Little odd with the UI (some options are off screen for me) but expected to be in active development so I look forward to updates.

I don't know what you are going to send for issues.
            - When it puts me on a ferry across Lake Michigan.... I run out of range but ferry transport doesn't use range.  (which can easily be fixed)
            - SWIPE to change models is still offered while editing settings... but you need to SAVE then swipe... unavailable option shouldn't present (which can easily be fixed)


It still recommends un-achievable routes (which is the bane of all so far).

Only uses one number for range when different roads have different speeds.

(i like that it has a weather overlay - (and again highest form... headwind (like elevation) range))

Title: Re: Aerodynamic & rolling resistance calulator
Post by: BrianTRice@gmail.com on November 30, 2016, 03:18:52 AM
I like EVtripn - it is definitely getting closer. $0.99 well spent.

Little odd with the UI (some options are off screen for me) but expected to be in active development so I look forward to updates.

I don't know what you are going to send for issues.
            - When it puts me on a ferry across Lake Michigan.... I run out of range but ferry transport doesn't use range.  (which can easily be fixed)
            - SWIPE to change models is still offered while editing settings... but you need to SAVE then swipe... unavailable option shouldn't present (which can easily be fixed)

It still recommends un-achievable routes (which is the bane of all so far).

Only uses one number for range when different roads have different speeds.

(i like that it has a weather overlay - (and again highest form... headwind (like elevation) range))


So, the author lives in Monterey, and I got the notice on Facebook and asked for contact info. The "report" link on the website links to a gmail address of the same name.