Some Thoughts for Formula 1 Aerodynamic Elements(01.08.2022)[overall sidepod concepts]

This is nonacademic post containing my own guesses for F1 aerodynamic elements.

Again, this is nonacademic post not including scientific proof.

I'm just doing this for future reference like a diary.

- Ferrari style sidepod 

1. aggressive outwash & downwash of forward portion: 

- clearing the front tire wake: Gotta say it's not "my" thoughts. It's more like one of the fundamental purpose of this season's sidepod.

- strengthening the low pressure area under the front corner of the floor: It seems it is more efficient to converge air with not only converging floor tunnel, but also with guiding the air outward(to the floor edge), which will give much narrower gap between the floor and the ground. The floor upper outwash may cooperate with this and enhance the low pressure underneath it. In addition, such outwashes could help managing the floor edge losses, too.

2. coke bottle area: I think this would be a weak point of this design. Since it is quite rapidly converging inwards, not only the boundary layer will thicken, but it will increase the inward rear tire wake expansion and decrease diffuser effeciency. 

I might add this: According to the simulation result of the Ferrari sidepod CFD article in F1 technical net, it seems the forward portion of the Ferrari sidepod outwashes so much that it can cause separation and generates wake. The article claims that this decreases the rear tire drag and it is indeed observed that the wake structure crashes into the rear tire. Probably this can reduce the rear tire wake. Also, I venture a theory that the rotation of the sidepod wake induces local outwash at the lower portion of the rear tire and might decrease rear tire wake even more. In addition, there seems quite a bit of separation in the coke bottle area as expected.

3. the tub design: Since the upper surface is upwashing, it is obvious that local high pressure will be built up at the upper rear portion of the tub. I'm curious whether this is a good idea for a)cooling outlet, b)rear wing efficiency. For a), since the adverse pressure gradient will worsen the boundary layer thickening and building high pressure at the cooling exit seems like not a good idea(perhaps it's the reason why the new Haas sidepod for Hungary has rather forwarded cooling exit.). Perhaps the forward portion of the tub generates low pressure area for cooling outlet and the upward curvature of the rear portion of the tub offset the boundary layer thickening. For b), we can draw a wing and corresponding lift and drag, and rotate our point of view to see how the upwash will decrease the efficiency. Actually, it is intuitive that it is hard to generate downforce by upwashing device from an airstream already upwashing.

Maybe the configuration is the most neat way to guide the cooling outlet gas in between the rear wing and the beam wing.

From the CFD article, it seems the tub also gives some inwash for the cooling outlet gas. If it is tricky to guide and maintain the exhaust in between the rear wing and the beam wing in various condition(maybe due to the yawing or vehicle slip angle) or if there is any negative effect in letting the gas through between them even though without the gas touching the surface, then it would be better to make the gas be concentrated inward as narrow as possible.

- Redbull style sidepod

1. gentle outwash in the middle and wide front upper surface of the floor: Inwash is going to be built up under the rear portion of the floor and some kind of spill flow loss will be at the floor edge. the out wash in the middle might help managing the loss by inducing outwash at the upper surface. Perhaps this out wash will help rear tire wake management. 

Wide front upper surface of the floor may help gaining the front end downforce in conjunction with the extended sidepod radiator intake. changing the intake design may help shifting the downforce balance easily.

2. downwashing upper surface of the sidepod: This seems to be helpful in many ways: a) low pressure build up for cooling outlet, b) gaining rear wing effiency, c) suppressing rear tire wake. a) and b) have been already mentioned above. Then for c), if the downwash meets the upwashing portion of the upper rear floor surface, it will create local outwash that will help suppressing the rear tire wake. The downwash itself may also suppress the rear tire wake.

3. Easier packaging: it seems much simple to package the radiator stuff with this sidepod compared to others.

- Mercedes style sidepod

1. radiator intake: They seems to be having a hard time clearing some boundary layer building up by the mid chassis and front upper downwashing floor surface as they trying lots of downwashing VGs and downwashing pushrod inward root area. I presume their philosophy is to secure the upper surface area of the floor as wide as possible, so that it can give broad high pressure area at the upper surface and lots of clean mass flow into the rear aerodynamic parts, which seemed to be important in the previous generation cars. Therefore, their radiator package couldn't stick out wide and it become like this. Perhaps, they think it is enough to clear the front tire wake with the floor strakes and floor fences(and the sidepod wing), so maybe they are rather avoiding unnecessary pressure drag by guiding chunk of air using sidepod.

2. sidepod wing: Kyle Engineering(Youtube channel) has already featured some professional insights so.. I'll skip this.

- Aston Martin style sidepod

It's the design that all abandoned..(Alfa Romeo was one of this but now it changed to a kind of Redbull style) Let's guess why.

1. managing cooling outlet gas: Not only it must be tricky to package the radiator in the narrow volume, but the efficiency of cooling will be also affected. Building low pressure area for cooling outlet will be challenging, then it will require more area for the outlet. It is definitely not good for managing the boundary layer and perhaps eventually affect the rear wing more badly. 

2. rapidly inward converging coke bottle area: Not sure whether the air will flow attached there. The rear tire might help it being attached but it seems a bit aggressive.

3. High pressure on the upper floor surface is compensated with the sidepod: I see this design is to provide clean air into the rear upper floor surface, beam wing, and around them. But the upper floor section has another job to do: to build high pressure that can push down the floor. Any high pressure built up on it will be compensated with the lower surface of the sidepod(upper surface of the tunnel formed by the sidepod and the floor), which might decrease floor efficiency.

- Mclaren style sidepod

I would say it's mild version of Mercedes sidepod(securing wide upper floor surface) but now they changed it to Redbull style downwashing sidepod so... no comments