Top is TJI, bottom is this rapid combustion: TJI/ HCCI / whatever you want to call it hybrid combustion concept, where a shockwave? causes combustion to start at the periphery as well as exit the TJI jets. Just shows the flame propagation. When you take the information of Ferrari using up 5 injection events per cycle /cylinder, you can get a feel for how the fuel is delivered to the chamber prior to being combusted.
Audi started using a Miller Cycle concept in 2015, of which, the current F1 engines are as well.
As for the pistons, you can imagine most of the chamber volume is in a bowl, especially to achieve the rules limited 18:1 geometric compression ratio. Audi in their diesel LeMans engines calls the bowl shape a "Mexican hat" with a central nipple. To quote "this is a key area of development in which we really save fuel". You can read plenty more in this issue:
https://www.highpowermedia.com/Product/ ... -issue-100
I like to think of the current F1 engines as gasoline, spark assisted, Miller Cycle "diesels" than anything. I think that's a pretty fair take.