A urban vehicle with very low fuel consumption: realization, analysis and optimization

The problem of energy saving is, at present, more and more important and the reduction of the consumption of the vehicles is a target that a lot of countries and car manufacturers are searching for. In this scenario Shell organizes a competition called Shell Eco Marathon; the winner of this race is the team that realize the vehicle capable of covering a fixed distance with the lowest fuel consumption. At the Politecnico di Milano a vehicle to participate to this competition has been realized. A high performance aerodynamic shape has been developed starting from the “Morelli's shape” which has been further optimized to reduce the aerodynamic drag. A CFD analysis has been completed to refine the vehicle shape and to reach the final body geometry. To reduce the frontal area the wheels have been connected to the main body by using CFRP wing beams and both suspension system and powertrain, have been integrated into the wheels. A highly efficient powertrain has been developed and an electronic differential has been implemented. All the subsystems have been optimized both to reduce the motion resistance of the vehicle and to maximize the efficiency. A numerical model of the vehicle has been developed in order to aid the design and to simulate the race strategy on different competition tracks. The model has been validated by considering data acquired during the race.