엔진 언더커버가 차량의 공력/열적 성능에 미치는 영향

Influence of engine undercover to vehicle aero/thermal performance was investigated by using a current state-of-theart CFD technique based on LBM (Lattice Boltzmann Method) and aerodynamic/climate wind tunnel tests. For the performance evaluation, three driving conditions were considered such as high speed (165 km/h, 20°C), mid speed (60km/h, 35°C, cooling fan on), and idle state (0km/h, 45°C, cooling fan on) for a C-segment passenger vehicle on mass production. CdA effect of the engine undercover estimated by the CFD simulation is 0.012m², which is quite same as the value from the aerodynamic wind tunnel test (0.011m²). For both high speed and mid speed with fan on condition, effect of engine undercover to engine cooling (radiator heat dissipation) and HVAC performance is almost negligible. However, at idle state, engine undercover has a negative effect on HVAC performance due to the increase of engine room temperature.