Verification Study toward the Strategic Drag Reduction Control of Practical Bluff Boies

我们在这个项目中涉及的六个研究课题如下：（1）作用在简化车辆模型上的涡流结构和气动阻力的机理，（2）动态流动控制的数学模型，（3）后缘涡流的不稳定性，（4）减阻控制的建议，（5）减阻控制对道路条件的影响，（6）真实的车辆减阻的战略技术。首先，通过对简化的车辆模型施加动态俯仰、偏航和换道运动，我们揭示了这些瞬态气动力是如何由车辆模型周围的非定常流结构引起的。将简化模型所获得的知识应用到真实的轿车外形上，阐明了阻力和升力如何通过车身上和车身周围的边界层和涡流结构而变化的机理，并研究了通过控制涡流结构来减小阻力的可能性。

The six research topics we have involved in this project are as follows: (1)Vortex structures and the mechanisms of the aerodynamic drag acting on simplified vehicle models, (2) Mathematical models for the dynamic flow control, (3) Instability of trailing edge vortices, (4) Proposal of the drag reduction control, (5) Effect of the drag reduction control on the on-road conditions, (6) Strategic technology for the drag reduction of real vehicles. First, by imposing dynamic pitching, yawing and lane-change motions on simplified vehicle models, we have revealed how these transient aerodynamic forces are caused by unsteady flow structures around the vehicle models. Applying this knowledge acquired by the simplified models to real sedan-type vehicle shapes, we have clarified the mechanisms of how drag and lift forces changes through the boundary layer and vortex structures on and around the vehicles, then examined possibility of reducing the drag by controlling eddy structures.