Post on 28-Jul-2015
March Newsletter
As a result of finishing 3rd in the UKand 9th overall at Formula StudentUK in 2014, Cardiff Racing qualifiedto apply for a large financial awardby the IMechE. Earlier this month,Mr Anthony Chowings from theIMechE, came down to awarded uswith £3000.The money will be spent on thefuture development of the car,particularly to improve reliabilityand performance. The donatedmoney will contribute towards thecost of tooling and further testingand development for a new carbonsandwich panel chassis.
Big thanks to the IMechE
A carbon composite chassis on the horizon?
The switch to a carbon chassis has numerous obstacles
to overcome before the use of this method becomes
viable. Due to the potential change in material the
current inserts can no longer be used. This is because
the ductile nature of the aluminium panel allowed a
“crush” type insert to be used. These gain strength
through the plastic deformation of the chassis around
the insert . However as composite materials are
somewhat brittle this technique is not suitable and an
alternative method for gaining insert performance
must be considered.
In the search of weight reduction, and therefore performance, a switch to a
carbon composite chassis for the 2015-16 season has been proposed.
Given that the insert system was beingcompletely re-designed this was a goodopportunity to improve the performance whencompared to the previous design. The insertscurrently used in the aluminium honeycombchassis have a tested pull-out strength of 11kN,requiring the use of three inserts per roll hoopattachment point to satisfy the FS structuralequivalency spreadsheet which states thateach attachment point must be capable ofcarrying a load of 30kN in any direction. Anincrease in insert strength would allow for areduction in the required number of insertssaving weight, a key factor in vehicleperformance. However, the spreadsheet alsostates that an attachment point may contain nofewer than two inserts. Therefore the targetinsert strength was set at 15kN (to satisfy the30kN requirement).
Tests were performed with different insertconfigurations in both shear and normaldirections to find the optimum insert systemthat was as light as possible but still met therequired strength target.
A few possible configurations were found tomeet the rules and therefore the lightest onewas chosen for recommendation for the finalchassis, which will be made over the comingmonths.
A carbon composite chassis cont…
EESW visitCardiff Racing was glad to returnto the Big Bang Fair event for thethird time. As always, there waslots of interest in our simulator,and the Ultimaker. We have alsostarted collecting drawings ofdragons from children. Thesewill be converted to digital imagesready to go on CR10’s vinyl, whichwill soon be transformed into ourtesting and show car.
Techniquest Visit
On the 8th March, Cardiff Racingattended the Brain Games held atNational Museum and Gallery ofWales. The whole day was basedaround how the brain works. We setup CR07 as a simulator in the mainhall, reversing the controls. This wouldcreate confusions to the built-in senseof direction in one's brain. The daywent well with lots of interest from thepublic. We look forward to returning.
We took our simulator down toTechniquest in Cardiff bay, as part ofthe national science andengineering week. Children andparents alike enjoyed it. We werealong side exhibits such as theBloodhound land speed racers.
Brain Games
Do wings really work?Do wings work? This is the question that has been asked year on year since wings were
first seen on a Formula Student car. This year with the new aero rules severely restricting
the size of allowable wings this question has become even more poignant.
At Silverstone in 2014 Cardiff Racing’s CR10 was the fastest car without an aero package,
so we are now assessing whether an aero package will give us what we need to improve
our score in the dynamic events.
But any potential improvements in dynamics would come at a disadvantage in the cost
event, as a result Cardiff Racing is carrying out a full cost benefit analysis of an
aerodynamics package.
Extensive modelling in CFD has been carried out to create an aero package, made up of
front and rear wings and a floor and diffuser, to test on CR10.
Physical testing will be carried out
on CR10 to acquire lift and drag
coefficients with and without aero.
This data will be fed into the
simulator we have been
developing that is capable of
simulating all the dynamic events.
Track times with and without aero
can be calculated and an adjusted
score for the 2014 UK event can be
calculated, this increase in points
will be compared to the decrease
in points seen in the cost event.
Soon Cardiff Racing will be able toanswer the real question teamsshould be asking “Are wingsactually worth it?”
More machining, more!Over the past month the machinesat Cardiff have been full timemanufacturing parts for the newcar. With the help of ourtechnicians we now have newwheel nuts, a new pedal box,ARB’s and the space frame isnearly fully finished.