Expert analyzes cartoon car aerodynamicsfrom @rfkracing

Transcript

Want me to analyze Lightning McQueen? Are you serious? Hey guys, I'm Seth Dillard, I'm a aerodynamics engineer at RFK Racing, and today we're gonna analyze a CFE simulation of Lightning McQueen. So, this first one here, this is just showing the three d pressure cloud section. Coming around the tires, you good this big, separation zone on the better, which is where the contact patch is hitting the ground. So you get a pretty large separation here. And then also coming over the top, around the edges of the windshield, you better lot of separation here as well. Front fascia here, where Lightning McQueen's mouth is is seeing a high stagnation buildup here. Now this might actually change depending on whether his, mouth is open or closed. And you can actually see on the boiler here that you've only got high pressure on the outer corners, which may be a symptom of the separation coming up front around, I yes, Lightning's eyebrows here. Typically, if you've got a spoiler here, you'll want this pressure buildup to be spilling onto the actual deck lid or the tail of the car right here. You do actually have somewhat of a downward angle, but it's mostly rearward facing. So this vector you're creating from this spoiler here is mostly gonna be a drag increase versus a downforce improvement. You can see the tires are building up stagnation pressure, where the contact patch is. Yeah, there's no underfloor, so there's gonna be a lack of downforce, I think. My girlfriend said this looks like tie dye. I thought that was pretty funny. There is a lot of patchiness here, and it kinda, I rank, just comes from basically the surface quality of what's going on here. There's a lot of separation tier, and it does look like there's kind of flow separating again in this spot, but typically, even unlike a regular race car you will see streamlines kind of going like this, but you will still have sometimes, pressure building up in the center, ideally when you've got good forward. If you want to compare Lightning McQueen to Chick Hicks, just comparing the spoilers, Lightning's got a pretty massive spoiler, so he should be getting a decent amount of downforce from this versus, check Hicks here. So Lightning should have probably a downforce advantage, I would think, over check Hicks here. That can end up giving more downforce and load through the tires and might actually have contributed to why his tires, exploded during the last lap rank. And now if we compare to Jackson Storm here, while his front fascia looks a little more sharp rank this might give him a little bit more drag than lightning, if you go over to the spoiler, he is actually using an airfoil profile, and does have a bit of a smaller, head here or greenhouse as we call it. And might be getting one, more flow to the spoiler, and two, it's not gonna be as draggy as Lightning McQueen's spoiler. So he would probably end up having a top speed advantage as well. This is probably why, Jackson Storm was able to pull away from Lightning McQueen in the third movie. Overall, I think it's a pretty good design. He did, in fact, win seventh Piston Cubs, so I don't think we need to change anything here.