This weekend begins the most famous solar-powered car race : the World Solar Challenge 2015 in Australia. ONERA will closely follow “Punch One”, a prototype car of KU Leuwen student team (Belgium), which benefitted from aerodynamic testing in the wind tunnel L2 Lille.
“Punch One” in the wind tunnel L2 at Lille. The vehicle is designed to travel as faster as possible, over a distance of 3,000 km using solar energy alone.
The most efficient solar devices in the world will participate in this race, from North to South of Australia (about 3,000 km). So this race is a real technological challenge for the teams. With an average speed of around 90 km / hour for the fastest, aerodynamics plays an important role, especially in headwind or crosswind conditions.
Tests were run in the L2 wind tunnel at ONERA in August 2015 : the speed range available in this facility corresponds to the conditions of the race. The ONERA specialists were able to measure the aerodynamic forces for different driving conditions (crosswind or headwind, at different speeds), study zones of turbulence (transition) on top of the vehicle, identify key vortices, and finally, compare with the numerical simulations that were used in the design of this vehicle.
Some shape optimizations were found in order to gain some drag reduction. Without waiting for the result of the race, it is a great achievement that ONERA has adapted its experimental equipment to tests such a land vehicle, and have been able to propose improvements.
Wind Tunnel Testing at ONERA by the Punch Powertrain Solar Team
A few links :
