Big Car - PokeTube

Big Car
4 days ago - 236 likes

Get the new Big Car video 5 days early as a podcast! Excellent to listen to.

Apple Podcasts: podcasts.apple.com/us/podcast/big-car-bitesized-ca…
Spotify: open.spotify.com/show/1tEQK1WPlF9hknD2dhdInn
Amazon Music/Audible: music.amazon.com/podcasts/cf15574a-9d87-4a9c-89ad-…
PlayerFM: player.fm/series/3556286
iHeartRadio: iheart.com/podcast/156870118
ListenNotes: www.listennotes.com/podcasts/big-car-bitesized-car…
Podchaser: www.podchaser.com/podcasts/big-car-bitesized-car-h…
Boomplay: www.boomplaymusic.com/podcasts/93546
Google Podcasts: podcasts.google.com/feed/aHR0cHM6Ly9mZWVkLnBvZGJlY…

Big Car
1 month ago - 746 likes

Get the Vauxhall Vectra Story as a podcast now! Video will follow on Friday.

Apple Podcasts: podcasts.apple.com/us/podcast/big-car-bitesized-ca…
Spotify: open.spotify.com/show/1tEQK1WPlF9hknD2dhdInn
Google Podcasts: podcasts.google.com/feed/aHR0cHM6Ly9mZWVkLnBvZGJlY…
YouTube Podcasts: www.youtube.com/playlist?list...
Amazon Music/Audible: music.amazon.com/podcasts/cf15574a-9d87-4a9c-89ad-…
PlayerFM: player.fm/series/3556286
iHeartRadio: iheart.com/podcast/156870118
ListenNotes: www.listennotes.com/podcasts/big-car-bitesized-car…
Podchaser: www.podchaser.com/podcasts/big-car-bitesized-car-h…
Boomplay: www.boomplaymusic.com/podcasts/93546

Big Car
1 month ago - 121 likes

Is the "ski pass through" option any use to you? If so, what do you use it for?

Big Car
1 month ago - 347 likes

What video would you like to see in the future?

Big Car
1 month ago - 62 likes

Why The Gas Turbine engine failed

On the back burner has been a video about Gas Turbine cars. Viewer Will Poundstone recently sent me some interesting research he'd done about why this engine failed. I thought you'd also find it interesting:

"After fairly exhaustive research, I think I can explain why gas turbine engines never succeeded in surface transportation.

The adiabatic flame temperature of kerosene is 2,093°C (3801°F). Gasoline is slightly hotter. Such a temperature is beyond the capability of all but the most exotic materials. This is not a problem in piston engines for 2 reasons

1. Combustion is intermittent and the time that the engine is exposed to those temperatures is short

2. The design makes it inherently easy to cool the pistons by circulating coolant through the engine walls.

In turbine engines, things are not nearly as simple

1. Combustion is continuous and so the turbine wheels are constantly exposed to this extreme heat

2. Cooling the turbine wheel with coolant is much harder as you'd have to pump liquid into the blades while the turbine is moving

So that turbine engines don't melt down, engineers are forced to dilute combustion with lots of excess air. This brings temperatures down to tolerable levels but results in lots of heat being wasted in the exhaust, especially at part throttle. Adding a regenerator to use the exhaust heat to warm up the inlet air helps some, but not enough.

The same issues apply to the turbine engines used on aircraft and power stations. The difference being that the relative advantages over piston engines are greater. Over the years, engineers have developed exotic (and expensive) alloys, thermal barrier coatings, and, more recently, turbine blades made out of ceramic matrix composites. These allow turbines to operate at higher temperatures and therefore improve efficiency.

If someone had developed a ceramic that wasn't brittle and could be made relatively cheaply, then turbine cars probably would've caught on, given their advantages in terms of weight, size, vibration, simplicity, torque, and multifuel capability, but that didn't happen and given the arrival of EVs, it probably never will."

Sources:
https://youtu.be/bKLWS_73TJk?si=IbuU1... how jet engines need to run very lean in order to not melt down)
www.jstor.org/stable/44562855?seq=7 (Fig. 8 shows how the exhaust of a typical two shaft gas turbine gets hotter as the load decreases, meaning more energy wasted as heat)
www.jstor.org/stable/44631888?seq=4 (Fig. 1 shows how increases in inlet temperature especially improves efficiency at part load)

Big Car
2 months ago - 394 likes

Patrick le Quément has written an article talking about the inspiration for the Audi TT, and the Renault Sport Spider, the Argos concept. Fascinating read.
driventowrite.com/2024/04/03/concept-cars-mon-amou…