5 ms·
Air density and temperature should both have an influence on the performance of electric vehicles, and both change with elevation.
by etendue 10y ago
Air density and temperature should both have an influence on the performance of electric vehicles, and both change with elevation.
- thescriptkiddie 10y agoMaybe on a very hot day cooling would become a factor on the track, but for a single 0-100 run air temperature should be irrelevant. Electric cars don't need to ingest hundreds of grams per second of air to make high power outputs. Unless you're referring to the impact of air density on aerodynamic drag, which should be negligible at such low speeds.
- function_seven 10y agoHome runs travel further at Coors Field. Field goals are longer at Mile High. Sprinters turn in faster times at higher altitudes. You can bet that the air density will affect vehicle acceleration tests significantly.
- thescriptkiddie 10y agoDrag scales with the square of velocity. A 110 mph home run experiences vastly more drag than a car traveling 30 mph on its way to 60 mph. The ball might fly 18% faster in Denver than it will at sea level, but the car isn't going to accelerate 18% faster.
- NamTaf 10y agoThere's a whole raft of other aspects. Temperature will affect traction, for example. Similarly, the pressure differential between the tyres and the atmosphere will change their performance similarly to pressurising tyres to a different pressure at sea level. There's a whole raft of influences that altitude may have that aren't immediately apparent. To say it has 'absolutely no impact' is simply wrong.
- function_seven 10y agoYou ignored the sprinter and the football in my list of examples.
- mikeash 10y agoAerodynamic drag is hugely significant. It dominates at highway speeds. Reduced drag will be very much noticeable on a 0-60 run.
- yincrash 10y agoDrag is definitely not neglible at those speeds.
- MagnumOpus 10y ago> the impact of air density on aerodynamic drag, which should be negligible at such low speeds The impact air density on aerodynamic drag is huge even in human athletic events - on the order of 1% or more [1]. The impact increases quadratically with speed so it should be 3-5 times more significant in the final stretch of a 0-60 than at the 25mph speed of a sprinter. [1] http://www.ingentaconnect.com/content/nrc/cjp/2003/00000081/00000007/art00001 http://www.ingentaconnect.com/content/nrc/cjp/2003/00000081/...
- etendue 10y agoI'll add to the other responses that downforce is also something to be considered and air density is a factor there as well. The person I was responding to said "absolutely no impact", which is absolutely incorrect. I don't have a great intuition of how significant these factors are on the model, but I would not dismiss the terms without careful consideration when we're measuring results in fractions of a second.