With the Bridgestone World Solar Challenge (BWSC) drawing closer, Cambridge University Eco Racing (CUER) has embarked on the first stage leading up to one of the greatest automotive challenges in the world. Their entry Mirage – which will shortly arrive in Australia – will have to endure a gruelling 3,000 km marathon from Darwin to Adelaide on 8th – 15th October 2017, facing some of the harshest conditions imaginable.
Mirage will be the seventh car designed and built by the CUER team, a group of 60 ambitious students from the University of Cambridge. Now celebrating their 10th anniversary, the team’s knowledge of automotive engineering and aerodynamics has enabled them to utilise cutting-edge technology to push the boundaries of what is possible for solar-powered cars.
Tony Purnell, Head of Technical Development at British Cycling and a member of CUER’s Steering Committee, comments that his endevours to achieve greater efficiency at British Cycling are not disimilar to that of the CUER team. He says:
“A bicycle has one human-horse power (300W), and Mirage has just four human-horsepowers. A bicycle on the Tour de France can achieve more than 25 mph over 2,200 miles, and Mirage will travel more than 60 mph over 1,870 miles. However, my road car needs 1,500 human-horse powers to get me from A to B and produces toxic gases. In that respect, it really is incredible just how efficient transport can be.”
Mirage has an ultra-light, teardrop profile that places aerodynamics at the forefront. With optimum performance in mind, the team has created a much smaller car than most other teams, with a smaller surface area of solar cells. These cells are made with satellite-grade high efficiency Gallium Arsenide, and for further efficiency the team have developed a solar tracking array which follows the sun’s trajectory and optimises the capture of sunlight through the day.
The team have also identified the battery as a crucial area where energy savings can be made. By developing and manufacturing a custom Battery Management System housed within the car, the team is able to regulate everything from battery temperature to power output.
Xiaofan Zhang, Project Manager at CUER, says that while a lot of hard work has gone into getting Mirage shipped to Australia, there are many more challenges to come:
“We have a built in passive cooling system this year, but nonetheless temperatures are expected to soar as high as 40°C. In addition to the drivers, a group of 20 CUER team members will follow the car each day, providing engineering support as required. It’s a massive achievement for us to get to Australia, and we couldn’t have done it without all our supporters, but it’s not over yet!”
Tom Nash, a spokesperson from Europe’s leading product and technology consultancy TTP, announces: “We are proud to once again support the CUER team at the World Solar Challenge 2017. We are delighted to support initiatives such as this which encourage engineers of the future to put their skills into practice to develop real world applications. We wish all those involved the very best of luck.”
Tony Purnell concludes: “Every time the CUER team enters the WSC it staggers me that a group of students, working in their spare time whilst doing one of the most challenging degrees going, can get to the start of the challenge with all the major components engineered by themselves save the battery and motor.
It's no surprise so many CUER alumni have gone on to start up their own businesses – once you’ve taken part in the WSC whilst completing a degree at The University of Cambridge, nothing can possibly daunt you!”