Electrical DesignL' Ran, J'R' Bumby, T'D' Short

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DURHAM UNIVERSITY SOLAR POWERED CAR
Introduction Durham University are developing a
high-performance solar powered car. After touring
the UK in the summer of 2004, visiting secondary
schools to promote science and engineering, it
is planned to compete in the World Solar
Challenge. This is a biannual race across
Australia for solar powered vehicles. The project
is an excellent match for Durhams School of
Engineering because it makes use of the Schools
expertise across the engineering disciplines.
Undergraduate design teams have developed a
number of concept vehicle designs and final year
research projects have considered key aspects in
detail. Vehicle layout Aerodynamic
Design D.B. Sims-Williams   This vehicle is able
to reach motorway speeds and at these speeds the
majority of the electrical energy provided by the
solar cells is consumed in overcoming the
aerodynamic drag. The design of the aerodynamic
body shell has been undertaken using both
computational fluid dynamics and wind tunnel
testing. A set of wind tunnel models were
designed in conjunction with the Department of
Mathematical Sciences in order to systematically
evaluate aerodynamic design parameters using a
minimal number of wind tunnel models. Para
metric wind tunnel models The 2m2 wind
tunnel Contact Opportunities exist for
companies wishing to become involved as technical
partners or as sponsors. For information
contact Dr D.B. Sims-Williams University of
Durham, School of Engineering South Road, Durham,
DH1 3LE Tel [phone] Fax 44(0)191
334 2390 d.b.sims-williams_at_durham.ac.uk
Electrical Design L. Ran, J.R. Bumby, T.D.
Short   The vehicle has a complex electrical
system including 9m2 of solar cells, 8 maximum
power point trackers, 5kWh of battery storage and
the electric drive motor. Vehicle
electrical system The maximum power point
trackers continuously optimise the resistance
seen by the cells in order to obtain maximum
power. The battery storage makes it possible to
drive at a desired speed independent of the
current solar conditions and this level of
battery storage makes it possible to store almost
an entire day of solar energy in the UK.
Conventional mechanical power transmission
systems introduce significant energy losses
therefore a high-torque, low speed direct drive
electric motor has been developed which
eliminates the need for a gearbox. The motor has
been packaged within the single rear wheel of the
vehicle with the tyre mounted directly on the
external rotor. Exploded view of wheel
motor The motor on test Mechanical
Design D.B. Sims-Williams, H. Long   The space
frame chassis has been designed and analysed
using the Strand 7 Finite Element Analysis
System. This makes it possible not only to verify
the strength and stiffness of the chassis through
static analysis but also to investigate
suspension behaviour and even to undertake crash
test simulations. Analysis of chassis
structure using Strand 7

Centre for Automotive Research