F1 Racing UK – August 2019

Fittingducts

tocoolthe

brakesonF1

carsseems

simplein

theory,but

inrealitythis

isared-hot

aerodynamic

andregulatory

battleground

PRO

RACING

05 Engineering

BRAKE DUCTS

WORDSJAKE BOXALL-LEGGE

48 F1 RACING AUGUST 2019

Ferrarihasaggressivelyshapeditsbrakedrumsatthe

front(top)andrear(bottom)tochannelairflowoutwards

PICTURES

ILLUSTRATIONS

Brake ducts? They’re justholes, aren’t they?

When it comes totalking technical in F1, thepowe rtrain

and aerodynamics always take centre stage. It’s only natural

that attention will be drawn to the audio-visual elements

• noise and aesthetic appeal have long beenthe sensory
  stimuli that can turn any motorsport fan’s knees to jelly.
  But this season has offered new areas of intrigue, with a
  more radical approach to suspension design, and included
  within that is a completely renewed focus on brake ducts,
  which have undergone considerable change over the off-
  season. In a move designedto stamp out the increasing
  number of flicks and protrusions from the front brake duct
  area, the FIA restricted thegeometryto fit purelywithin
  the radius ofthe wheel rim. That included the duct itself,
  meaning that brake cooling required something of a rethink.
  At the rear, things are a little different because there are
  far fewer restrictions. The space available for bodywork
  means that, from the rear, an array of stackedwing lets
  resemble small DVD racks.
  In the age of streaming,
  DVDs lurch closer to the
  pits of obsolescence, butthe
  continued development of the
  brake duct-mountedwing lets
  shows little sign of abating.
  For 2020, F1’s brake ducts
  are slated to become a listed
  part – that is, the bodywork
  associated with the braking
  assembly and suspension
  upright must be produced by
  each team in-house. Teams are
  currently able to buy them in
  from competitors, something
  that Haas takes advantage of
  by purchasing the Ferrari-
  designed ducts and drums.
  Cooling for brakes and
  the usual dissipation of the
  ensuing hot air has changed
  with the thinner-gauge Pirelli
  tyres, which have theoretically
  become easier to heat up – but
  also easier to cool down. The
  fluctuation in tyre temperatures throughout a race have
  been a lot for the teams to get their respective heads around,
  and only Mercedes has truly got to gripswith it.
  A lot of that is downto the suspension kinematics,
  which seem naturally equipped to getthe tyres within the
  right working range, coupled with the overall downforce
  generating the right amount of load inthe tyres. But in its
  brake duct design, Mercedes also has another trick - not
  only does it have the traditional opening to provide the

much-needed brake cooling, but it’s also got a small channel

built into the “cake tin” - thecarbon fibre shroud around the

brake assembly.

This isfed by an opening that’s set back fromthe whee l

rim once attached and, as airflow meandersthrough it is

pulled out through the centreof the wheel. This is an attempt

to recapture the effectofthe blown axle, somethingthat

appeared on many cars in 2018and wasbanned for2019.

Ferrari has a different approach, and has been running

asymmetrical ducts this season. For a circuitwith

predominantly right-handed corners, Ferrari has put a

second aperture on the right-hand upright, aiming to kick

out a bit more heat from the brakes. For anti-clockwise

circuits, such as Baku, those designs are reversed. At the

inside wheel, its deceleration is greater than that of the

outside, aided by the Ackermann steering geometry (the

offset betweenthe r otation of the left and right front wheels

to aid cornering), and so there’s a lot more heat to expel.

Those ductschannel airflow

out aggressively,through a

small opening into an areafor

expansion – akin to a diffuser

• to accelerate itoutwards. It’s
  the design Haas uses, but next
  year it’s expectedthe American
  team will havet o develop
  its own. That’s perhaps not
  such a bad thing, give n the
  complications it hasstruggled
  with in2019.By developing
  a bespoke product it could
  divert some of the excessheat
  into the tyre, should it suffera
  recurrence of its current tyre
  conundrum in 2020.
  In the banning of the
  majorityof aerotricks used to
  eke the most outofthe duct
  geometry,some teams have
  come across a loophole. At
  the front, any non-suspension
  components can onlyprotrude
  from the insideface o f th e
  upright by 5mm.But b y
  sinki ng in that inside face, there’smorearea to play with.
  This opens a space for a number of sma ll fins, w hich ar e
  sharplyangled downwards. Able topick upthe rotationa l
  flow from the wheel,the fins can turn it awayand towards
  the bargeboardgeometry. In that, F1 teams havethe outward
  jet of airflow andthe conditioningof rotational flow at both
  sides to minimise the disruption produced behind.
  With ‘listed’ status there’ll be more variations, and when
  F1 gravitates to 18”wheels in 2021,it’ll be all-change again.