Technical Analysis: Mercedes' internal S-duct trickery

The Mercedes S-duct has already been covered by us on several occasions on the lead-up to the 2016 season proper.

However, more details about its internal operation came to light in Australia.

Mercedes W06 front suspension bay

Photo by: Giorgio Piola

The first time that it became apparent that an S-duct may be on the agenda for 2016 was when Mercedes tested an interim solution in Brazil last season.

The test completed during free practice was done in combination with a revised suspension layout, that required an extensive revision of the pedal box and brake reservoirs, which led to a considerable amount of downtime as the team switched back to their standard configuration for the rest of the weekend.

The S-duct tested in Brazil was an early sighter for the team, a marriage of convenience, which helped it understand if its 2016 concept worked. It was far from refined, as can be seen by the bump needed to house the raised position of the heave element below.

Mercedes W07 new nose

Photo by: Giorgio Piola

The Mercedes-style S-duct is a revelation, as the regulations stipulate no holes, except for driver cooling, can be placed in the nose ahead of a line 150mm forward of the front wheel centreline.

Instead, a clever geometric trick, similar to the one used by Force India with their nose 'nostrils', is employed to beat the single section rule. Meaning that, should a slice be taken through the nose at any point, you still cannot discern a hole.

Mercedes W07 nose, outline

Photo by: Giorgio Piola

The goal to circumnavigate the regulations in this way means the designers have placed the inlets in a more desirable location, taking in airflow at a point where it might otherwise become turbulent and/or help other aerodynamic structures.

This also improves how the airflow moves through the ductwork, from under the nose to the upper surface of the chassis.

Ferrari F2008 "F" wing hole Spain

Photo by: Giorgio Piola

This puts the Mercedes S-duct in closer lineage to Ferrari's F2008 solution than the one adopted by teams post rule change in 2009.

Airflow taken in by the two inlets underneath the nose passes through the pipework, which is split into two, allowing the geometry to circumnavigate the single section rule and miss the pitot tube stack, which is mounted centrally and would otherwise hinder how the airflow is ejected.

Mercedes W07 "S" duct

Photo by: Giorgio Piola

The vanity panel, which also covers the suspension elements, features two holes, fashioned to meet with the internal pipework and allow the airflow passage to the outlet further back, entraining otherwise errant airflow back to the chassis surface, improving performance.

Scuderia Toro Rosso STR11 S duct

Photo by: Giorgio Piola

Toro Rosso is employing a similar tactic with its nose design, which also features inlets in the exclusion zone.

However, it has opted for four inlets, the smaller two of which deal with driver and electronics cooling, whilst the larger inlets pass airflow through ductwork inside the nose box and eject it out of the upper surface of the nose.