Baku gamble: Set up and standing waves

Video simulations or not, there are always unknowns when travelling to a new circuit and Baku is a brand new track that will host this weekend’s European Grand Prix. How much downforce will a car need, when and where will it need it? That long, long straight betrays the concept of a Monaco Street circuit and yet there is a tightened section that would be akin to the streets of the Monte Carlo track.

A new tarmac in some places with differing abrasion leaves and this place Pirelli in much the same position as the teams with a new circuit. One of the concerns is the same issue that, according to Motorsport, left Sebastian Vettel with a blown tire at Spa—tire standing waves.

Pirelli boss, Paul Hembery, said:

“Long straights can create standing wave issues,” Hembery said. “It seems to be a circuit that shouldn’t be too dramatic, but it has that straight, so we have to be very careful on that in terms of what’s going on with the standing wave management.

“If you go to a new circuit, it can throw up some surprises. The tendency to new circuits in recent years is smooth surfaces with very low levels of wear, but there is quite an aggressive straight and standing wave is something we have to manage, so there is an aspect of tyre integrity that we have to monitor well.”

The article is certainly interesting as, to be completely honest, I had not heard that a tire standing wave was Vettel’s issue and the article doesn’t explain much about what this condition is.

If a vehicle’s speed exceeds a certain ‘critical velocity’, intensive flexural waves travelling around the circumference of the tire can emerge from the trailing edge of the contact patch. To the observer these waves in the tire appear to be stationary. Here is a quick video that shows a similar, if not dramatic, version of it:

The long straight is certainly a concern in Baku for this type of issue but if the teams dial in a lot of downforce tactically believing that more speed can be gained through the twisty bits rather than the long straight, the critical speed may not be achieved. I guess all that depends on how the cars are set up.

Hat Tip: Motorsport