Cooling System Drag variability (some examples)

[ME_Andy]

To the author of several aero books:

We got in a discussion about grille size and cooling load here. The F150 EV was unveiled last night. Here's a side-by-side comparison with the grille of a conventional F150. I marked the grille openings in red. EV is on the left.

Do you still think that size of the grille opening is not an indicator of cooling load? Any comments?

Keep in mind, the F150 ev is probably both more powerful and heavier than its ICE counterpart.

[JulianEdgar]

Originally Posted by ME_Andy

To the author of several aero books:

We got in a discussion about grille size and cooling load here. The F150 EV was unveiled last night. Here's a side-by-side comparison with the grille of a conventional F150. I marked the grille openings in red. EV is on the left.

Do you still think that size of the grille opening is not an indicator of cooling load? Any comments?

Keep in mind, the F150 ev is probably both more powerful and heavier than its ICE counterpart.

I am not sure what point you are trying to make. I am interested in cooling drag as a proportion of total aero drag, and on the BEV cars for which we have the data, the cooling drag proportion is not at all low. Unprompted, an expert car aerodynamicist I have been working with said much the same to me the other day - the cooling drag of electric cars isn’t actually low, as had been expected. If you have data on cooling drag as a proportion of total drag, please share it.

[ME_Andy]

Well, where does all of that cooling come from? It can't be that tiny slot in the grille, right?

[JulianEdgar]

Originally Posted by ME_Andy

Well, where does all of that cooling come from? It can't be that tiny slot in the grille, right?

No idea. I don’t guess and make up theories. I go on measured data.

[Piotrsko]

The volt batteries dump maybe 700 watts of heat into my battery coolant tank during a 30 minute freeway trip from my ex-job to home or vice versa, giving a 10 degree rise above ambiant. The Kostov / soliton is radiating an average of 1.5 k watt because that's what I planned on cooling and do not overtemp limit. The truck uses an average of 450 wh/mile with the high being 2.5kw on a 6% hill.

One would think the F-150 is much more efficient than my 30 year old technology in a bumpy brick shaped non aerodynamic vehicle.

[aerohead]

Originally Posted by ME_Andy

Well, where does all of that cooling come from? It can't be that tiny slot in the grille, right?

You're on the right track. Thermodynamics clearly supports your line of thinking.
Virtually cherry-picked quanta, from two sources, cannot possibly represent the entire spectrum of BEV cooling system drag percentages.
Expect context. Conditions. Thinking people demand no less.

[aerohead]

Originally Posted by Piotrsko

The volt batteries dump maybe 700 watts of heat into my battery coolant tank during a 30 minute freeway trip from my ex-job to home or vice versa, giving a 10 degree rise above ambiant. The Kostov / soliton is radiating an average of 1.5 k watt because that's what I planned on cooling and do not overtemp limit. The truck uses an average of 450 wh/mile with the high being 2.5kw on a 6% hill.

One would think the F-150 is much more efficient than my 30 year old technology in a bumpy brick shaped non aerodynamic vehicle.

* When the official specifications are provided for the electric F-150, we'll be able to do a side-by-side comparison with the EcoBoost F-150, converting everything to Btu or Joules.
* With the current Ford Mustang MACH-e test comparison with Tesla Model Y, we already know how more efficient Tesla is than Ford, so we'll also have a feel for the upcoming F-150 / Cybertruck shootout.
* Right now, Tesla is around 300% more efficient than ICE. About 570%, on a well-to-wheels basis.
* The Btu / Joule content of the battery packs and fuel tanks, compared to hourly consumption rates, under similar load, will tell the tale about cooling system heat flux rejection requirements. Dimensions. Drag.

[Autobahnschleicher]

I just don't get why the electric model doesn't come with some kind of aeroshell for the bed and a more optimized front.
Many users here have seen quite significant improvements in fuel economy from an aeroshell here, wich would give the truck a longer range.
The CDA of that thing must be insanely high, resulting in a lot of energy wasted to aerodynamic drag.

[aerohead]

Originally Posted by Autobahnschleicher

I just don't get why the electric model doesn't come with some kind of aeroshell for the bed and a more optimized front.
Many users here have seen quite significant improvements in fuel economy from an aeroshell here, wich would give the truck a longer range.
The CDA of that thing must be insanely high, resulting in a lot of energy wasted to aerodynamic drag.

My opinion is that, to include any type of aeroshell, would be an admission as to the superior design of Cybertruck. It's nemesis. Not good PR.
Technically, a RAM 1500 BEV, could easily take the Cd 0.357 of the ICE variant, and with the clean underbody of the electric, plus the minimized cooling requirement of the BEV power train, easily come in at Cd 0.30, to match Cybertruck, IF it keeps the OEM full tonneau cover.
General Motors 'invented' the aeroshall, and military HUMMERs have used a variation of it. We'll have to wait and see if it becomes available as a high-performance option, as our own Brett Herndon tried for FoMoCo.
AeroStealth owned one of Brett's F-150 'Cybertrucks' in 2014, although it did require Brett's aero boat tail to get Cd 0.3.

[Autobahnschleicher]

Originally Posted by aerohead

My opinion is that, to include any type of aeroshell, would be an admission as to the superior design of Cybertruck. It's nemesis. Not good PR.
Technically, a RAM 1500 BEV, could easily take the Cd 0.357 of the ICE variant, and with the clean underbody of the electric, plus the minimized cooling requirement of the BEV power train, easily come in at Cd 0.30, to match Cybertruck, IF it keeps the OEM full tonneau cover.
General Motors 'invented' the aeroshall, and military HUMMERs have used a variation of it. We'll have to wait and see if it becomes available as a high-performance option, as our own Brett Herndon tried for FoMoCo.
AeroStealth owned one of Brett's F-150 'Cybertrucks' in 2014, although it did require Brett's aero boat tail to get Cd 0.3.

The big issue with trucks isn't just their bad CD, it even gets multiplied by their large frontal area.
And since electric motors don't gain efficiency under load like internal combustion engines do, the issue will be more significant with electric trucks.
If you compare the CDA of a Tesla Model S with that of such a truck without a cover, you will see that the truck will get less range out of a certain sized battery on a highway driving the speed limit.
And that's where range matters the most to the average consumer.