Electric cars and cooling drag

[JulianEdgar]

Originally Posted by aerohead

I believe you're attempting to be useful, however the limited data you've provided is limited, contextual, and un-actionable.
If you can't fill in the blanks, then we're at an impasse.

Er no, we go on the data that is available.... which completely contradicts what you have written here many times.

If new data appears that then changes that, great.

[aerohead]

Originally Posted by JulianEdgar

Er no, we go on the data that is available.... which completely contradicts what you have written here many times.

If new data appears that then changes that, great.

I repeat, in more understandable terminology. It's useless to us as presented.

[JulianEdgar]

Originally Posted by aerohead

I repeat, in more understandable terminology. It's useless to us as presented.

It may be for you; it's not for me.

I don't have any preconceived notions about what ICE and BEV cooling drag percentages are - I just look at the currently available data.

This shows that:

1) On current BEVs, percentage cooling drag is nowhere near zero.

2) In fact, the sample of two BEV cars for which we have percentage cooling data available shows the cooling drag to be quite high - and higher than many ICE cars.

[aerohead]

Originally Posted by JulianEdgar

It may be for you; it's not for me.

I don't have any preconceived notions about what ICE and BEV cooling drag percentages are - I just look at the currently available data.

This shows that:

1) On current BEVs, percentage cooling drag is nowhere near zero.

2) In fact, the sample of two BEV cars for which we have percentage cooling data available shows the cooling drag to be quite high - and higher than many ICE cars.

There are some areas of information which remain blank and may provide the necessary caveats with which an observer might be empowered to profit from what you've provided in part. Without this additional information, the data presented so, far lacks rigor.
You may be comparing ice cubes to icebergs.

[freebeard]

Perhaps there is a 'cooling coefficient' that is dimensionless like Cd. With Area as a stand-in for total heat load? [ducks and covers]

[aerohead]

Originally Posted by freebeard

Perhaps there is a 'cooling coefficient' that is dimensionless like Cd. With Area as a stand-in for total heat load? [ducks and covers]

It would be the coefficient of heat transfer ( U ), which is the inverse of the R-Factor. Typically it has to do with the material chosen. Aluminum versus cork for instance.
Once the material is chosen, then it you're looking at your delta-T.
Everything will be compared on an equal thickness/per-square-foot, or similar area basis.
Your heat 'sink' is the atmosphere, and we can't control it's enthalpy. It is what it is.
In a liquid-to-liquid heat transfer, as with a nuclear-powered naval vessel in the Arabian Gulf, you may just have to set sail and leave when the water temperature becomes so high you endanger the reactor.
Upping your input temp increases the delta-T, and increases thermal efficiency, however, in an ICE engine, that might mean a burnt valve, molten piston top, or loss of lubricant viscosity, high-pointing, then engine seizure.

[aerohead]

Tesla Model S ( non-aero wheels ) cooling = 0.01976
Tesla Model S ( aero wheels ) cooling = 0.018
2007 Ford Fusion cooling = 0.025
The Ford is a smaller, lighter car.

[JulianEdgar]

Originally Posted by aerohead

Tesla Model S ( non-aero wheels ) cooling = 0.01976
Tesla Model S ( aero wheels ) cooling = 0.018
2007 Ford Fusion cooling = 0.025
The Ford is a smaller, lighter car.

I don't now where you're getting your data from, but I am quite certain it was never measured to five decimal places...

Round them, divide by total car Cd, then multiply by 100.

As I have been saying, the percentage cooling drag of BEVs (at least for cars on which we have data) is not low at all.

[aerohead]

Originally Posted by JulianEdgar

I don't now where you're getting your data from, but I am quite certain it was never measured to five decimal places...

Round them, divide by total car Cd, then multiply by 100.

As I have been saying, the percentage cooling drag of BEVs (at least for cars on which we have data) is not low at all.

* The Tesla data is from you.
* The Ford/Buckeye, Fusion 999 data is from FoMoCo.
* You also gave us Hucho's 0.025 cooling, on an estimated Cd 0.40 car of 1981.
* Your Joseph Katz gave us 13.5% for a generic Cd 0.355 vehicle in 2017.
* The 1999 Audi A2 is 10.27%.
* Gary Eaker has personally measured cooling drag from 0.05, to 0.100
* The 1963 Corvette Stingray was 12%.
* Ford of Cologne's 'Lamellar' grille was good for delta-12%.
* The 1936 Adler-Jaray was 15.78%.
* 2016 Jaguar XJ Supercharged 8.62%, from you.
* 2016 Land Rover Range Rover, 10.29%.from you and me.
* 2004 Jaguar, Cd 0.30, 125-mph car, 15.66%. from you.
* 2008 Ford of Australia, Falcon sedan, 8.0%. from you.
* 2008 Ford of Australia, Falcon wagon, 13.48%. from you.
--------------------------------------------------------------------------------------
1) The two examples given are for a 160-mph car, and a 155-mph car.
--------------------------------------------------------------------------------------
2) The only valid scientific comparison we could make, would be for cars of identical CdA and Rolling-Resistance at 160-mph and 155-mph.
------------------------------------------------------------------------------------
3) Considering Vekke's 2021 VW ID3 of top-speed= 99.4-mph, operating the same car at 155-mph would require the aero load portion of the radiator area to be increased by a factor of 379%.
4-a) At 160-mph, the radiator's aero portion area would have to increase by 417%.
4-b) The Rolling-Resistance portions would only have to increase arithmetically, assuming zero-standing wave.
--------------------------------------------------------------------------------------
5) You haven't mentioned that 1/3rd of an ICE engine's waste heat is lost through the exhaust system!
------------------------------------------------------------------------------------
6) You haven't mentioned that, in the 'AGE of Thermal Management', that thermal loads may be separated out to dedicated systems for:
a) Radiator
b) transmission
c) oil
d) intercoolers
e) differential
f) brakes
g) electronics
h) climate control
i) tire cooling
j) solar insolation
k) thermal conduction
l) thermal radiation
m) electronic noise cancellation
n) electronic noise introduction
o) 'Track-Mode'
p) 'Super' Mode
-------------------------------------------------------------------------------------
* Even at the time of Hucho's December, 1986 publication, there were 'passenger' cars with top speeds which exceeded 'racing' cars.
--------------------------------------------------------------------------------------
If we're going to compare cooling systems, we need a single variable to do it.
CONTEXT
CONTEXT
CONTEXT

[JulianEdgar]

Originally Posted by aerohead

* The Tesla data is from you.
* The Ford/Buckeye, Fusion 999 data is from FoMoCo.
* You also gave us Hucho's 0.025 cooling, on an estimated Cd 0.40 car of 1981.
* Your Joseph Katz gave us 13.5% for a generic Cd 0.355 vehicle in 2017.
* The 1999 Audi A2 is 10.27%.
* Gary Eaker has personally measured cooling drag from 0.05, to 0.100
* The 1963 Corvette Stingray was 12%.
* Ford of Cologne's 'Lamellar' grille was good for delta-12%.
* The 1936 Adler-Jaray was 15.78%.
* 2016 Jaguar XJ Supercharged 8.62%, from you.
* 2016 Land Rover Range Rover, 10.29%.from you and me.
* 2004 Jaguar, Cd 0.30, 125-mph car, 15.66%. from you.
* 2008 Ford of Australia, Falcon sedan, 8.0%. from you.
* 2008 Ford of Australia, Falcon wagon, 13.48%. from you.
--------------------------------------------------------------------------------------
1) The two examples given are for a 160-mph car, and a 155-mph car.
--------------------------------------------------------------------------------------
2) The only valid scientific comparison we could make, would be for cars of identical CdA and Rolling-Resistance at 160-mph and 155-mph.
------------------------------------------------------------------------------------
3) Considering Vekke's 2021 VW ID3 of top-speed= 99.4-mph, operating the same car at 155-mph would require the aero load portion of the radiator area to be increased by a factor of 379%.
4-a) At 160-mph, the radiator's aero portion area would have to increase by 417%.
4-b) The Rolling-Resistance portions would only have to increase arithmetically, assuming zero-standing wave.
--------------------------------------------------------------------------------------
5) You haven't mentioned that 1/3rd of an ICE engine's waste heat is lost through the exhaust system!
------------------------------------------------------------------------------------
6) You haven't mentioned that, in the 'AGE of Thermal Management', that thermal loads may be separated out to dedicated systems for:
a) Radiator
b) transmission
c) oil
d) intercoolers
e) differential
f) brakes
g) electronics
h) climate control
i) tire cooling
j) solar insolation
k) thermal conduction
l) thermal radiation
m) electronic noise cancellation
n) electronic noise introduction
o) 'Track-Mode'
p) 'Super' Mode
-------------------------------------------------------------------------------------
* Even at the time of Hucho's December, 1986 publication, there were 'passenger' cars with top speeds which exceeded 'racing' cars.
--------------------------------------------------------------------------------------
If we're going to compare cooling systems, we need a single variable to do it.
CONTEXT
CONTEXT
CONTEXT

Sorry, but that's back to your usual mix of irrelevant data, incorrect data (nowhere in my book do I quote Tesla's cooling drag to five decimal places) and weird extrapolations.

The only relevant data is cooling drag as a percentage of total drag on current BEVs - a dataset to which you have added nothing.

And all in a scrambling defence of the fact that, again, you have been writing stuff here that is demonstrably incorrect.