A major challenge hindering the advancement of the automotive industry is finding a way to reduce the aerodynamic drag of transport vehicles, thereby promoting fuel saving and environmental pollution control. The advanced bio-inspired CRF considerably reduced the drag coefficient of the 15-ton by approximately 20%. The side force was also reduced by up to 8% for the 15-ton at a yaw angle of ϕ = 3°. The bio-inspired CRFs significantly reduced the regions of separated shear flow and turbulent kinetic energy level on the side surfaces of the vehicle models. The findings prov...   내용 보기

Some winged seeds exhibit autorotation flight during their descent to migrate far away from the parent trees by oncoming wind. In this study, several prominent features of the autorotation flight were investigated experimentally. Velocity fields of the flow around an autorotating maple samaras model were measured by PIV technique with controlling wind speed to be similar to the descending velocity. As a result, a highly stable LEV is attached on the leeward side of the autorotating seed.   내용 보기

Nowadays people spend lots of time in their car. With increasing living standards, there is a trend to pursue for a comport environment inside the car. However, since most previous studies were performed using CFD or scale-down models, the ventilation flow results are different from that in the passenger compartment of a real car. In this study, a real Hyundai NF SONATA was modified slightly to visualize and analyze quantitatively the ventilation flow inside the passenger compartment under real operation condition using a PIV system which has specially designed to measure veloc...   내용 보기

Windbreak forest has been used for centuries for various purposes including reduction of wind speed, control of heat and moisture transfer and pollutant diffusion, improvement of climate and environment, or increase of crop yields. These functional effects of windbreaks are directly related to reduction of oncoming wind speed. However, systematic studies on the shelter effects of windbreaks have been performed only recently. Most previous experiments contain little quantitative flow information, either in laboratory wind tunnel experiments or in the field studies, because experim...   내용 보기