Longitudinal vortex formed at the rear area of the vehicle is one of the main sources of vehicle aerodynamic drag. The boat tail shape is applied to reduce the longitudinal vortex strength of the SUV so that the aerodynamic drag is improved. For this study, a commercially available SUV produced by domestic automobile company, Hyundai Motor Company, is selected as a baseline model. The boat tail shape is modeled on the baseline model using the morphing technique. The effects of boat tail shape on the aerodynamic drag has been numerically analyzed for a SUV with or without undercover. A commercial flow solver, ANSYS Fluent, is used for this study. The driving speed of SUV is 140 km/h. Even though the same boat tail shape is applied to the same vehicle, the aerodynamic drag improvement depends on the flow pattern behind the vehicle. It can be improved when the strength of the longitudinal vortex is weakened by the airflow generated by the boat tail shape.

在车辆后部形成的纵向涡旋是车辆空气动力阻力的主要来源之一。采用船尾形状以降低SUV的纵向涡流强度，从而改善了空气阻力。在本研究中，选择了由国内汽车公司现代汽车公司生产的商用SUV作为基线模型。船尾形状使用变形技术在基线模型上建模。船尾形状对空气阻力的影响已经通过数值分析了带或不带底盖的SUV。这项研究使用了商用流量求解器ANSYS Fluent。SUV的行驶速度为140 km / h。即使将相同的船尾形状应用于相同的车辆，空气阻力的改善也取决于车辆后方的流型。