Aerodynamics of ARTeC's PEC 2011 EMo-C Car

摘要

A formula-type car design with fendered rear tyres is chosen as the ARTeC's design for 2011 Perodua Eco-Challenge. This paper aims at investigating aerodynamics of ARTeC's EMo-C car, measuring drag coefficient in particular and observing airflow around the body. There are two means of measuring the drag, the first is by simulating the air flow via computational fluid dynamics (CFD) suite, and the second is by using wind tunnel experiment. Observation on air flow around the body is also highlighted here with emphasis on the results from CFD simulation. From computational simulation (CFD) and wind tunnel experiment, the Emo-C car's drag coefficient is 0.42 to 0.48, respectively, the difference between the two is around 12.5 percent. The former has lower value than the latter due to inviscid flow modelling which disregard skin friction, hence the existence of boundary layer on the body panel (viscous flow). Tyres accounts for 25.7 percent of profile drag coefficient. Without tyres, the car experiences down force but opposite effect (lift) is observed when tyres are included. At average race speed of 40 km/h, the aerodynamic drag only accounts for no more than 20 percent of the overall power required from the engine and slightly less than six percent of the estimated total fuel consumption of the car.