PRUETT: Inside the development of IndyCar's Aeroscreen

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PRUETT: Inside the development of IndyCar's Aeroscreen

Insights & Analysis

PRUETT: Inside the development of IndyCar's Aeroscreen

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A problem reported by Dixon and Newgarden in testing, involving an eddying effect as air passed over the top of the Aeroscreen prototype and pushed their helmets forward, has been addressed in 2.0.

“One of the problems is now the head sits in this completely cocooned atmosphere,” Belli said. “The positive pressure that we normally get on the front of the helmet, which… let’s take the AFP for example: we discovered a couple of weeks ago, you reduce that positive pressure, which is like just between the eyes and above the eyes, which pushes the helmet back. Once that moves away, the helmet tends to get pushed forward by the air going over the top and gets in between the headrest.

“The slots that you see at the base of the windscreen are mainly to try and inject some airflow back at the helmet to push it back a little bit against the other aerodynamic forces that are trying to push the helmet forward. So they’re not really for driver ventilation, because they are aimed quite high at the helmet, and of course, you don’t cool the driver on his helmet. You need to cool the driver on his torso.

“Then you have the effect, [that] now there is very little air spilling over the cockpit rim down onto the torso of the driver. We have to provide a bit more air into the cockpit, so where we have a hole where the anti-roll bar is, and we’re going to try to push some air down there and push that air over the whole body. It basically goes from the driver’s feet all the way up over his body and then out of the car.”

Designed to withstand a blow of 150 kilonewtons – nearly 34,000 pounds – Belli and RBAT will pivot from the Indy 500 press conference and begin work on testing Aeroscreen 2.0 in the lab and on the racetrack in the coming months.

“We’ve been really pleased,” he said. “All the calculations done by Dallara and Red Bull show that the tub with this type of mounting can take the 150 kilonewtons, and we’ve just gone from there. Obviously we have tried to make a step forward in having the halos constructed, and we are trying to make it look a little bit nicer too.

“The project has three phases. Phase one was to make sure that the idea was feasible. So that was really FEA analysis of the tub with a pretend top frame, and to do some basic aerodynamics studies, although the aerodynamic studies go all the way through to the end of phase two. So phase one is complete, and we’re probably about one-third of the way into phase two, which is to start designing the top frame in mind for detail manufacturing.”

The final version of the Aeroscreen will incorporate additional tweaks for practicality.

The new Aeroscreen will carry a few practical improvements missing on the prototype.

“We’ve had to take into account some other things like fogging, so the screen will have a heating element in it,” Belli added. “We’re looking at tear-offs and reflections and all sorts of other possible issues that we get. Driver cooling we’ve mentioned. Helmet forces take a lot of effort, and Red Bull has done the first FEA analysis on the top frame production, phase one production design top frame, and they’re now going through a second iteration, because we want to minimize the weight of the top frame. So we don’t want to put material where we don’t need it, and we want to maximize material where it is needed.

“We are a couple of weeks to three weeks away from making a rapid prototype version of the top frame, which we will recheck in the Dallara simulator for sight lines. There are certain things that have happened with the screen, so in putting the heating element in, you need a certain amount of thickness top and bottom where what they call the bus bar, which was where the main copper comes along to the heating elements that go down the screen, and you can’t see through those areas. So, we’re just tuning, and next week we’ll start manufacturing parts so we can go in and make sure the sight lines are OK on the top frame and the bottom frame.”

Managing the dozens of smaller projects that comprise the greater Aeroscreen program will continue through the summer.

“Then we’ve got to get into the detail design phase that goes through the end of July,” he said. “We have to obviously decide who’s going to manufacture the windscreen, and we have to start deciding who’s going to manufacture the top frame and the bottom frame. Then we have to take the prototype frames and put them into a fixture and do the load test on the first frames that we make. We’re going to make three to five frames to start.

“We have to do ballistic testing. We plan to fire a weighted wheel assembly like you see in the FIA, the whole assembly, but we also plan to do ballistic tests. We’re firing a one-kilogram piece of aluminum at a 220 mph. These materials, the design criteria and the windscreen material, have all passed these sort of tests in the past.”

Franchitti, speaking for the racers who will benefit from the Aeroscreen 2.0 program, welcomes the arrival of a generational evolution to IndyCar. In looking ahead, it’s time to leave exposed helmets to the past.

“Everybody has their own opinion about it, and I’m not going to tell anybody what to think,” he said. “But Christian Fittipaldi used to have a great saying. He would turn around and say, ‘Well, [five-time F1 champion Juan] Fangio used to race in a leather helmet. Doesn’t mean we should.’”

Hear more insights from Belli, Franchitti and Horner in the full podcast interview below:

 

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