British Grand Prix Aero Analysis

F1 came back to its home in England with a great race taken place at Silverstone. Most teams have made noticeable upgrades on their cars, although tyre issue caught all the attention by the end of the day. Pirelli states that “a series of different causes led to the failures, including rear tyres mounted the wrong way around, low tyre pressures, extreme camber angles and high kerbs”. Although they could blame a combination of various causes, it’s really the time for them to take a serious look at those tyres they made.

In aerodynamics perspective, Lotus brought out the DRD systems that they’ve been developing since last year, Ferrari modified both their front and rear wing, and Red Bull made some change to their diffuser.

Lotus DRD
I have written about the DRD on Lotus E20 last year – Lotus E20 Drag Reduction Device. DRD is basically a passive air switch that operates by air velocity. Several teams have tried out this device including Red Bull, Mercedes and Sauber. However Lotus was the only one who insisted and has a possibly €12.5m budget on it. Lotus E21 is designed with DRD inlets, however it was mostly closed during the season. In Silverstone, DRD was put on Raikkonen’s car while kept closed on Grosjean’s car. Lotus have also made different modifications to the car body based on DRD.

Lotus E21 without DRD
Lotus E21 without DRD
Lotus E21 with DRD
Lotus E21 with DRD

There is an obvious periscope shape outlet on Kimi’s car with DRD fitted. Romain’s car however, without DRD, features a slimmer body with shark fin on it. And correspondingly a slimmer monkey seat was used on Romain’s car. The slimmer bodywork may improve the performance of diffuser and rear wing without DRD.

Lotus E21 Monkey Seat Variation with/without DRD
Lotus E21 Monkey Seat Variation with/without DRD

The different setup on two cars would enable Lotus to carry out direct comparison between the package with DRD and a whole new package without DRD. And hopefully they’ve got some valuable data from Silverstone so that we can see more of their development on the drag reduction device.

Ferrari’s Front and Rear Wing

Ferrari added a new cascade (green arrow below) on their front wing, which improves the airflow rearward by directing more air over the suspension into the sidepod.

Ferrari's Front WIng at Silverstone
Ferrari’s Front Wing at Silverstone

At the rear end, they added a vertical slot on the side of the rear wing endplate. This could potentially help dealing with the wake come off the rear wheel.

Ferrari's Rear Wing at Silverstone
Ferrari’s Rear Wing at Silverstone

Red Bull

Red Bull modified their diffuser with some additional slotted strakes to seek for more downforce.

Red Bull Diffuser at Silverstone
Red Bull Diffuser at Silverstone

Force India

Another obvious update is from Force India, who added some vortex generators on the front wing as Red Bull did in Canada. They would create more guidance to the air and re-energise the flow to make it better attached to the surface.

Force India - Small vortex generators on the wing
Force India – Small vortex generators on the wing

*Pictures from AMuS


McLaren Spa Updates

With a dominant win from Jenson Button in Spa, McLaren has demonstrated their aerodynamic excellence after two successional win. It’s shame that Lewis was crashed out at the beginning of race, leaving us curious about how those two differently set-up cars would actually do in the race. Instead of seeing huge impact from DDRS, what drew attention is actually McLaren’s rear wing adjustment and sidepod airflow conditioner, while their DDRS remains a mystery.

High Downforce vs Low Downforce – Hamilton’s Deleted Tweets

The hottest topic outside the track is definitely Hamilton’s tweets during the weekend. Three of them get delated in two days, among those ghost tweets, the most famous one is the telemetry chart of the two McLaren cars.

Source: F1Technical

McLaren Overlaid Telemetry Chart

It looks a bit completed as there are lots of information merged into one single chart. However, telemetry chart is simple to read when you know which property each line represents. As a common approach of F1 data collection and analysis, a telemetry chart in fact can’t leak out too much serious information. Here is an example of a telemetry chart from 2010, which as an coincidence, is from Lewis Hamilton again. From the top to the bottom, properties plotted on the y-axis are speed, engine revolutions/gear, throttle/brake usage, lateral/longitudinal G force.

Telemetry chart in Bahrain 2010

As we can guess in Lewis’ leaking out chart, the most fluctuated lines represent his speed and Jenson’s. It’s obvious that on straights, Lewis’ car accelerates slower and has lower top speed compared to Jenson’s. Basically Jenson’s car has a low downforce configuration while Lewis get a high downforce one. The picture below combines Lewis’ and Jenson’s car during qualifying – with lower angle of attack, Jenson’s car has reduced downforce and drag, which gives him huge advantage on straights.

Source: Sutton Image

Comparison between Jenson’s and Lewis’ Car During Qualifying

However, this doesn’t mean lower downforce is always better on high speed circuits like Spa – downforce at severe corners should always be considered; weather condition has vast impact as well. Nevertheless, McLaren has clearly found the best compromise this weekend for Jenson.

McLaren New Sidepod Airflow Conditioner

The most evident change on MP4-27 in Spa is these airflow conditioners added on top of the sidepods.

McLaren Sidepod Airflow Conditioner

Now the airflow conditioner is connected to the cockpit and runs all the way over the sidepod. It’s expected to further regulating flow around the sidepod and towards the exhaust channel. In Hungry before the summer break, McLaren was using 3 fins on top of the sidepod as vortex generator to improve airflow.

McLaren Sidepod in Hungry

These fins would help smoothing the air by generating controlled vortex flow:

Effect of Vortex Generator

Although vortex generator is a good idea, McLaren seems to find those L-shaped covers over the sidepod working better in controlling the air.

Curiosities – Flexible Front Wing? DDRS?

An interesting picture of McLaren front wing in Spa indicates that it’s flattened during the race:

McLaren Flattened Front Wing

There was suspicion from ScarbsF1 that McLaren use flexible front wing to achieve better aero balance last year in Valencia – McLaren European GP Wing Movement. However although the suspicion was broadly argued, this picture still arise doubts on McLaren tricking on their front wing. Theoretically flexible front wing uses a joint rather than a rigid structure that allows the wing to tilt slightly backwards at high speed. The reduction of angle of attack would reduce front downforce/drag so that it corresponds to the reduction of rear downforce when DRS is activated. Because of the increasing limitation on rear part design, McLaren has actually focused a lot on the front part this season, as reflected in their lifted nosecone earlier this season.

Source: F1Technical

McLaren Nosecone Update

Although the so-called McLaren DDRS was buzzing before the race, there was no clear technical sources leaking out regarding this part. Some says there’re strange bumps on the rear endplates, which could mount in tubes like the Mercedes DDRS. However we still need to wait for more information to make judgement.

Bumps in McLaren Endplate

Besides McLaren, most teams have noticeable updates in Spa. There were more information of Lotus DDRS leaking out though it was not used in this race and is expected to be used in Japan Grand Prix. Also closed cockpit looks favourable in the future considering the huge crash in this race. These topics are hopefully covered in my future posts.