This year's Daytona 500 was the first points paying outing for the Generation 7 Cup car. This particular generation of NASCAR Cup Series cars has been designed to appear more symmetrical and more like the road going counterparts which these cars purport to market, even though in practice, they bear absolutely no relation to what is on the road at all.
Underneath the car, the powerplants are identical to the Generation 6 Cup Series car from last year and the several seasons previous. The engines are still the same 360 cubic inch V8s that they were before. The gearbox/differential however, is an entirely brand new piece of kit and is a single unit transaxle at the rear of the car instead of a gearbox at the bell housing at the back of the engine and a separate differential at the back.
The aerodynamic devices both on top of the car and underneath it which have been changed significantly. Far more downforce is produced by the undertray of the car, with a diffuser at the rear to channel the air out the back and create an area of low pressure underneath the car. The rear spoiler has been changed slightly and the front splitter has also had changes.
However, one of the headline controversies about this new car was the blowover of Harrison Burton after a series of unfortunate events when he was pushed and tagged from behind. Already people want to blame the aerodynamics of the car for causing the blowover and have compared it to the Gen-5 cars (otherwise known as the Car of Tomorrow or CoT). Back then, people who should have known better and did not, blamed the rear wing for the blowovers and flips of the Gen-5 cars but if you drill down into the data, the actual number of blowovers actually went up after the rear wing of the Gen-5.1 was replaced with the simple rear spoiler of the Gen-5.2. The problem and the lack of understanding has to do with a basic ignorance of physics and vectored forces.
In general a force has both a magnitude and a direction. It is simply not enough to ascribe that a mass being accelerated has a force, that force and the kosmos of other forces which that mass finds itself in, all play a part in determining what happens to that mass. I think that it should be pretty obvious that a thing doesn't exist all by itself in free space with no interaction with any other thing.
The question then is, how do you get a car which weighs several thousand pounds, to lift off of the ground and roll over? How can air of all things do this? Again it should be pretty obvious that when you start applying big forces to things, then big consequences will happen.
This is the actual point in time when Harrison Burton's Mustang begins to lift of the ground. A race car which is designed to go very very quickly and which is pointing nose into the wind is designed from the outset, that the air flow both over and underneath the car should both push and suck it onto the road. Again it should be obvious that when that car is pointed in another direction, that the various forces due to the air flow over and under it, are going to act differently.
It should also be obvious from this particular photograph, that the face of the car which is presenting itself to the wind, is the right hand side of the vehicle. Instead of a relatively pointy nose being presented to the wind, we have a slab side which is more like the flat side of a brick. Air is hitting the side of the vehicle and as the vehicle is moving through the air which has mass, the air has to find a way to be pushed aside. Either the air can go over the car (which nominally has the tendency to to push the car downwards) or it can go under the car (which nominally has the tendency to to push the car upwards).
Already, all of the flaps and baffles which are designed to direct air through the car have opened. At 200 miles an hour (which is no exaggeration here), the sheer volume of air that needs to be redirected when the car is facing sideways is impossible to be redirected as a result of those flaps and baffles.
The only place for the air to go really, is over and under the car and as soon as enough forces in an uncontrolled omnishambles start chaotically acting in all directions every which way, some of them are going to act int the same direction due to the momentum of the vehicle and push it upwards.
It is impossible to blame the diffuser or the rear wing of this particular car to act in any meaningful way because they are not being presented to the air flowing above and below the vehicle. When the car is sideways, wings and diffusers may as well be doing nothing at all (obviously they exist in time and space so their effect is not zero but is negligible). In this respect, this blowover is no fault of the aerodynamic devices which aren't being presented to the airflow. For the same reason, the blowovers occurring in the Gen-5 era were also not being presented to the airflow.
The thing is that this experiment has been repeated over and over and over again and in practically every incident, a car becomes partly airborne at the point when it is sideways. When you compare the area available underneath a car which interacts with the air with the area available with either the diffuser or a rear wing, the area underneath a car is many many times larger than that of those other components. Basic reason should tell you that a big thing has more of an effect than a small thing. Maybe there are individual point vectored forces which are larger but this is like asking someone if they would like a teacup of $100 notes or a bathtub full of $20 dollar notes. I'll take the bathtub, thank you.
I personally think that the biggest culprit in these kind of accidents is the repeated use of pushing by the car behind. This kind of tactic exists in no other form of motorsport and the fact that it is used in NASCAR, I think directly equates with the abnormal number of blowovers. Again, this has to do with vectored forces and a car pushing another car, merely adds vectored forces to other vectored forces needlessly. It is monumentally and chaotically stupid.
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