lorenfb
Posts: 1181
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: Aeromod nissan leaf improved aerodynamics increased range

Thu Feb 16, 2017 9:11 pm

GetOffYourGas wrote:When the vehicle is coasting, it has some kinetic energy that has already been put into the system via the motor. It will slowly lose that energy to rolling resistance and to aero drag..


The goal is to measure the energy consumption while just moving at various speeds, and not the initial
energy to obtain each speed. That more effectively determines the energy efficiency of the aerodynamic mods.

GetOffYourGas wrote: The rolling resistance is constant (independent of speed) and the drag is related to speed by a well known equation.


The energy consumed by a vehicle's rolling resistance is:

Energy = K m V, where K is a constant & wheels related, m is the weight of the vehicle, V is the velocity of the vehicle


The energy consumed by a vehicle's drag resistance as it moves thru the air is:

Energy = K A V^2, where K is the coefficient of drag, A is the frontal area of the vehicle, V is the velocity (it's squared)
of the vehicle.

As can be noted from above, the vehicle's speed does affect both the rolling resistance energy loss and the drag
energy loss.

VitaminJ
Posts: 358
Joined: Tue Jan 03, 2017 11:46 am
Delivery Date: 07 Jan 2017
Leaf Number: 415775
Location: Morrison, CO
Contact: YouTube

Re: Aeromod nissan leaf improved aerodynamics increased range

Thu Feb 16, 2017 9:45 pm

lorenfb wrote:The goal is to measure the energy consumption while just moving at various speeds, and not the initial
energy to obtain each speed. That more effectively determines the energy efficiency of the aerodynamic mods.

That's your goal. My goals are less strict and I put my ideas into practice. I encourage you to do the tests yourself. You can make a grill block out of a piece of cardboard, there is no excuse not to try it.
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- Leaf Box
- 2lb 5Ah LiFe 12v battery

lorenfb
Posts: 1181
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: Aeromod nissan leaf improved aerodynamics increased range

Thu Feb 16, 2017 9:58 pm

VitaminJ wrote:
lorenfb wrote:The goal is to measure the energy consumption while just moving at various speeds, and not the initial
energy to obtain each speed. That more effectively determines the energy efficiency of the aerodynamic mods.

That's your goal. My goals are less strict and I put my ideas into practice. I encourage you to do the tests yourself. You can make a grill block out of a piece of cardboard, there is no excuse not to try it.


I commend you for your perseverance!

GetOffYourGas
Posts: 1506
Joined: Tue Dec 20, 2011 6:56 pm
Delivery Date: 09 Mar 2012
Location: Syracuse, NY

Re: Aeromod nissan leaf improved aerodynamics increased range

Fri Feb 17, 2017 7:41 am

lorenfb wrote:
GetOffYourGas wrote:When the vehicle is coasting, it has some kinetic energy that has already been put into the system via the motor. It will slowly lose that energy to rolling resistance and to aero drag..


The goal is to measure the energy consumption while just moving at various speeds, and not the initial
energy to obtain each speed. That more effectively determines the energy efficiency of the aerodynamic mods.

GetOffYourGas wrote: The rolling resistance is constant (independent of speed) and the drag is related to speed by a well known equation.


The energy consumed by a vehicle's rolling resistance is:

Energy = K m V, where K is a constant & wheels related, m is the weight of the vehicle, V is the velocity of the vehicle


The energy consumed by a vehicle's drag resistance as it moves thru the air is:

Energy = K A V^2, where K is the coefficient of drag, A is the frontal area of the vehicle, V is the velocity (it's squared)
of the vehicle.

As can be noted from above, the vehicle's speed does affect both the rolling resistance energy loss and the drag
energy loss.


Yes. We are both correct. You are talking about energy loss and I am talking about force. The amount of energy consumed by rolling resistance is proportional to the velocity of the vehicle. But then again, so is the distance traveled. Consider two vehicles: A and B. A is traveling twice as fast as B, but they go the same distance. Vehicle A loses energy to rolling resistance at twice the rate of vehicle B, but for half the time. In the end, they both lost the same amount of energy for the trip.

My point still stands. Rolling resistance is independent of speed. And you just supported that claim.
~Brian

EV Fleet:
2011 Torqeedo Travel 1003 electric outboard on a 22' sailboat
2012 Leaf SV
2015 C-Max Energi (302A package)

GetOffYourGas
Posts: 1506
Joined: Tue Dec 20, 2011 6:56 pm
Delivery Date: 09 Mar 2012
Location: Syracuse, NY

Re: Aeromod nissan leaf improved aerodynamics increased range

Fri Feb 17, 2017 7:43 am

VitaminJ wrote:
lorenfb wrote:The goal is to measure the energy consumption while just moving at various speeds, and not the initial
energy to obtain each speed. That more effectively determines the energy efficiency of the aerodynamic mods.

That's your goal. My goals are less strict and I put my ideas into practice. I encourage you to do the tests yourself. You can make a grill block out of a piece of cardboard, there is no excuse not to try it.


And it's an overly restrictive goal. It is not the only way to measure the effect of wind resistance. I'm not sure why lorenfb is requiring it to be - physics certainly doesn't.
~Brian

EV Fleet:
2011 Torqeedo Travel 1003 electric outboard on a 22' sailboat
2012 Leaf SV
2015 C-Max Energi (302A package)

2011RedLeaf
Posts: 24
Joined: Tue Jan 03, 2017 8:49 pm
Delivery Date: 10 Oct 2012
Leaf Number: 3999

Re: Aeromod nissan leaf improved aerodynamics increased range

Fri Feb 17, 2017 10:58 am

It seems to me that the discussion about windtunnels vs observed improvements in daily driving range is similar to medical journals which divide data into POEMs and DOEs.
DOE is Disease Oriented Evidence - if I take this pill, my blood pressure will go down about that much. If I take a different pill, the results of my cholesterol lab tests will show a change in the good cholesterol and bad cholesterol concentrations or an ultrasound of my carotid artery will show less thickening.
POEM is Patient Oriented Evidence That Matters. Review of numerous patients shows that those taking some pills live longer with fewer heart attacks than those that don't.
Patients are more interested in POEMs. Researchers tend to study DOEs.
Some interesting results occur from contrasting results. Zetia was looking really good when DOE results showed lowered concentrations of bad cholesterol & less thickening of carotid arteries. Unfortunately, with more experience, the POEM showed no reduction in heart attacks or improvement in longevity. It turned out the medications (statins) effective in the DOE and POEM research were having an improvement in oxidation of cholesterol, which had been missed in early DOE research.
In this case, the information most interesting to me is - having purchased a 2011 Leaf & missed the battery lottery by 2 months - will pizza pans, beer-cooler Styrofoam, pilfered political posters & some Zip ties allow me to continue to commute to and from work without having to stop & charge my car on the way home? An extra five miles of range per charge, whether from driving more carefully, decreased wind resistance, or invisible unicorns pushing the car will save me a bunch of hassle.

lorenfb
Posts: 1181
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: Aeromod nissan leaf improved aerodynamics increased range

Fri Feb 17, 2017 11:24 am

GetOffYourGas wrote:
lorenfb wrote:
GetOffYourGas wrote:When the vehicle is coasting, it has some kinetic energy that has already been put into the system via the motor. It will slowly lose that energy to rolling resistance and to aero drag..


The goal is to measure the energy consumption while just moving at various speeds, and not the initial
energy to obtain each speed. That more effectively determines the energy efficiency of the aerodynamic mods.

GetOffYourGas wrote: The rolling resistance is constant (independent of speed) and the drag is related to speed by a well known equation.


The energy consumed by a vehicle's rolling resistance is:

Energy = K m V, where K is a constant & wheels related, m is the weight of the vehicle, V is the velocity of the vehicle


The energy consumed by a vehicle's drag resistance as it moves thru the air is:

Energy = K A V^2, where K is the coefficient of drag, A is the frontal area of the vehicle, V is the velocity (it's squared)
of the vehicle.

As can be noted from above, the vehicle's speed does affect both the rolling resistance energy loss and the drag
energy loss.




Read it again! There're two factors affecting energy loss while the vehicle is moving:

1. the rolling resistance energy loss - not affected by any aero mods & contributes the most below 45 - 50 MPH, increasing tire pressure beyond normal has minimal effect
2. the drag energy loss - has the most effect at highway speeds greater than 50 MPH, without major body
re-designs and when driving at speed limits, aero mods have little to no REAL effects.

Without any real data, e.g. using a scientific methodology, the results provided in this thread are no better than conjecture!

VitaminJ
Posts: 358
Joined: Tue Jan 03, 2017 11:46 am
Delivery Date: 07 Jan 2017
Leaf Number: 415775
Location: Morrison, CO
Contact: YouTube

Re: Aeromod nissan leaf improved aerodynamics increased range

Fri Feb 17, 2017 11:29 am

lorenfb wrote:Read it again! There're two factors affecting energy loss while the vehicle is moving:

1. the rolling resistance energy loss - not affected by any aero mods & contributes the most below 45 - 50 MPH, increasing tire pressure beyond normal has minimal effect
2. the drag energy loss - has the most effect at highway speeds greater than 50 MPH, without major body
re-designs and when driving at speed limits, aero mods have little to no REAL effects.

Without any real data, e.g. using a scientific methodology, the results provided in this thread are no better than conjecture!

10/10 brilliant trolling sir.
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- Leaf Box
- 2lb 5Ah LiFe 12v battery

GetOffYourGas
Posts: 1506
Joined: Tue Dec 20, 2011 6:56 pm
Delivery Date: 09 Mar 2012
Location: Syracuse, NY

Re: Aeromod nissan leaf improved aerodynamics increased range

Fri Feb 17, 2017 11:41 am

lorenfb wrote:Read it again! There're two factors affecting energy loss while the vehicle is moving:

1. the rolling resistance energy loss - not affected by any aero mods & contributes the most below 45 - 50 MPH, increasing tire pressure beyond normal has minimal effect
2. the drag energy loss - has the most effect at highway speeds greater than 50 MPH, without major body
re-designs and when driving at speed limits, aero mods have little to no REAL effects.

Without any real data, e.g. using a scientific methodology, the results provided in this thread are no better than conjecture!


Yes, and might I suggest you read my comment again?

Your assertion that "aero mods have little to no REAL effects" is what is pure conjecture.
~Brian

EV Fleet:
2011 Torqeedo Travel 1003 electric outboard on a 22' sailboat
2012 Leaf SV
2015 C-Max Energi (302A package)

VitaminJ
Posts: 358
Joined: Tue Jan 03, 2017 11:46 am
Delivery Date: 07 Jan 2017
Leaf Number: 415775
Location: Morrison, CO
Contact: YouTube

Re: Aeromod nissan leaf improved aerodynamics increased rang

Fri Feb 17, 2017 11:53 am

Almost exactly 2 years ago lorenfb had different ideas about the validity of the aero mods we're doing:

lorenfb wrote:
TomT wrote:Ford published statistics on the fuel efficiency improvement that came about from the shutterstats that they incorporated in to some of their vehicles... When they were completely closed, blocking off the grill entirely, the efficiency improvement was approximately 5%...


That sounds about what one might expect.


5% isn't real. It's FAKE efficiency!
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- Leaf Box
- 2lb 5Ah LiFe 12v battery

Return to “Accessories / Mods”