SingaporeGP Tech Updates

After going through two low downforce cicuits Monza and Spa, F1 came to Singapore, a narrow street circuit requiring high downforce. Correspondingly, most teams brought new setup for this track, while some of them gives a speed boost, others don’t seem to benefit anything. Successful examples are Red bull’s new break ducts and Mercedes Coanda effect exhausts. However Ferrari, using Alonso’s word, had a development error again, while Lotus expierenced a lack of grip throughout the weekend.

Mercedes

They’ve finally joined the group of ‘Coanda’ Exhaust after it was introduced by McLaren early season and used by Ferrari, Sauber, etc. The new exhaust utilise sidepod bulges to improve airflow passing through the sides of the car to the floor. Coanda effect basically describe the tendency of fluid attaching to the nearby surface. The bulge would help bending the flow at exhaust area down to the diffuser, therefore seal and speed up the airflow to create a low pressure area underneath the car. This effect increases downforce at the rear and gives advantage at low speed corners – that’s why it’s preferred in Singapore.

Mercedes Coanda Exhaust

Red Bull

The narrow street circuit indicates huge pressure on the brakes and cooling system. Red Bull came with new brake discs and ducts made of CER, a new material whose wear resistance feature is about 4 times better than the old CCR.

Source: F1 Official Site

Red Bull Singapore Front Brake Duct Detail

They’ve also modified their front wing with slots in the front of wheel area to reduce wake behind and seperate flaps to decrease drag induced by the high downforce setup.

Red Bull Singapore Front WIng

Williams

Williams was in quite good pace in Singapore actually with Maldonaldo hitting 2nd in qualifying, although hydraulic problem for Maldonaldo and KERS problem for Senna leave both drivers nothing in this race. They’ve introduced a much more rounded nosecone with centre bulge in this race, quite similar to the Lotus one.

Source: F1 Technical

Williams Singapore Nosecone

Ferrari

They brought two sets of wings into Singapore with the new one having more louvres on the endplates and deeper cuts on the top flap. There’s also 8 gills added to the side of the diffuser, wishing to generate more downforce. However, testing result on Friday was rather frustrating so that the team decided to use the oler version for Singapore race. This happened quite a few time throughout the season, which makes Alonso quite worried – Ferrari focused on understanding ‘development errors’

Source: F1 Official Site

Ferrari Singapore Rear Wing – Not Used

McLaren

They’ve modified their rear wing for Singapore and here is a nice flow viz picture of it.

McLaren Singapore Rear WIng Flow VIz

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Lotus E20 Drag Reduction Device

There’re quite a few comprehensive analysis on Lotus E20 Drag Reduction Device, however I’m trying here to put on a simple explanation to the system so that everyone can understand.

Lotus DRD, we call it DRD instead of DDRS as this system is nothing related to DRS, although the function is the same – reducing drag. It’s completely passively controlled by car speed to achieve drag reduction. The benefit of isolating from DRS (compared to the Mercedes DDRS system) is that it’s not limited use to the specific DRS area on the circuits and does not have a delay over activation – the Mercedes DDRS needs to go all the way from the rear wing to the front wing, causing delay.

The whole structure of this device looks like this:

Source: ScarbsF1

It basically contains two inlets – the airbox and the ‘ears’ and two outlets – the periscope/L duct and the mini diffuser/monkey seat. I’m not going through the internal ducting as it’s purely speculation going into this area, for which I’m not very sure about.

Inlet

Besides the normal airbox inlet, Lotus places two additional inlets along each side of it like two ears. Those ears help directing excess flow into the rear part, thus reducing turbulence from air spillage and help generating more downforce when DRD is not activated. In addition, it’s suspected that the air that goes into the ears and airbox subsequently flows into different route through internal ducting to the rear outlets. However, as I’ve mentioned, I’m not going into detail on this.

Source: Sutton Image

Airbox and ‘Ears’ On Lotus E20 Airbox

Outlet

There are two ways that the air can goes out of the car, either through the mini diffuser or the L duct. The path that the air goes depends on the speed, or air pressure.In a relatively low speed, i.e. off throttle condition, air mainly goes through the mini diffuser since higher pressure is required to push air through the narrow L duct. As the critical speed reaches, air can pass into the L duct then exit through 2 slots on each side of the duct, causing stall on the main plain of rear wing.

The structure of both the mini diffuser and the L duct is quite tricky if you look into the detail.

For the mini diffuser, there’s actually a small internal part inside which aids downforce generation when device is not activated.

Lotus E20 Mini Diffuser/ Monkey Seat Detail

The L duct is very narrow to ensure that it’s only activated when a certain speed is reached, those tiny air exiting slots make huge difference to the airflow pattern  – cause flow separation to stall the wing. The FlowViz picture can clearly show this effect:

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Lotus E20 Flow Viz Interpretation

Basically Flow Visualization paint is a special liquid sprayed to the car in order to study airflow on the surface. When the car runs, flow pattern is recorded as the paint redistribute due to the air goes over. So as can be seen in the Lotus Flow Viz illustration, there’s a V-shape pattern beneath the main rear plain right in the middle at the exit of the L duct, indicating flow separation, i.e. drag reduction. Also those 3-5 cm slots are shown clearly once zooming in to this area:

Lotus E20 L duct/ Periscope Slots Detail

The device need to be adjusted from race to race to modify the speed of activation, mainly by modifying the cross section of the mini diffuser and the L duct.

So as Mercedes came up with the intelligent DDRS which is activated by DRS, Lotus brought out a entirely passive system DRD. However, neither of the systems has given distinctive advantage to their cars. Regardless of that, it’s still a very clever idea that may inspire engineers for more innovation.

Monza Low Downforce Setup

There is no circuit in F1 that looks simpler than Monza, a typical circuit dominated by long straights. In response to this, downforce is not that favourable here, on the contrary, low downforce setup aiming to reduce drag is the key to win the race.

Front Wing

Front wing is not often changed significantly from race to race as it is the part that determines downstream flow, therefore affecting the design of all following parts. However, for Monza, most teams have adjust their front wing by removing cascades, lower down AoA or reducing chord length.

McLaren has removed all the outer cascades and replaced their 2-section upper flap with one single upper flap.

Source: Formula1.com

McLaren Front Wing Change from Spa to Monza

Source: Sutton Image

McLaren Front Wing in Monza

Another noticeable change on front wing is from Ferrari, who has removed all the small upper cascades and made several changes to the flaps and endplates profile.

Source: Formula1.com

Ferrari Front Wing Comparison from Spa to Monza

Rear Wing

The rear wing design is closely related to exhaust/cooling, sidepod and rear diffuser. Teams have different adjustments based on their cars. Major methods to reduce downforce/drag in Monza includes slimming rear wings, introducing V-shape profile and use gurney flap on diffusers.

With Massa hitting 3rd in qualifying and Alonso finishing on podium from 10th start, Ferrari proved their speed in Monza. They modified the beam wing with a V-cut profile and slimmed outer span, fit gurneys along the trailing edge of the diffuser, and quite uniquely, added flaps above and below the diffuser. The V-cut supplies the car with enough downforce at corners with low downforce setup for straights. Use of gurneys and additional flaps help regulating the flow, correspondingly reducing drag.

farrari monza rear design
Source: ScarbsF1

Ferrari Rear Design for Monza

Similar to Ferrari, Red Bull also used a V-shaped beam wing, in combination with a rear wing of very small AoA. They’re among the teams that suffer the most from the ban of exhaust blown diffuser this year and quite obviously still haven’t found a ideal design for their underbody rear part. In Monza, they’ve also added an additional tier to the diffuser gurneys, though that didn’t seem to give them clear benefit.

Red Bull V-shaped Beam Wing

Source: Sutton Image

Additional Tier on RB8 Diffuser Gurney

As the low downforce rear wing has clearly given Button huge advantage in Spa, McLaren is quite happy using this setup for both cars in Monza with a few modifications to further reduce drag. Instead of slimming the wing as other teams, McLaren cleverly introduced a curved profile at the tip of their beam wing to smooth air flow.

Source: ScarbsF1

McLaren Rear Design for Monza – Note Curved Tips on Beam Wing

Lotus has drawn wide attention because of their so-called DDRS system – It’s still quite confusing how people call this device though. Anyway we’re not seeing it until Singapore since Monza is not a preferable circuit for this system. In Monza, Lotus runs on the shortest chord rear wing, which makes it look quite tiny from behind.

Source: F1 Technical

Lotus Rear Design for Monza

Check this post from ScrabsF1 for more detailed analysis of rear end design based on each car relating exhaust/cooling/sidepod to rear wing assembly.