Bluff-body wakes and turbulent flows

“钝体”具有非流线型的形状和非常高的阻力系数。钝体周围的流动是复杂的，其特点是有一个大范围的分离流动，其中的流动不遵循物体的形状。在物体下游的低压尾迹中，可能是非定常的，也可能是湍流的，当漩涡从物体表面周期性地释放出来时，就会发生涡流脱落的现象。在某些条件下，旋涡脱落可能会引起不必要的结构运动，称为“流致振动”。我的研究计划的主要科学目标是促进对钝体尾迹的物理理解，其中重点是绕过表面安装的有限高度钝体的流动，例如有限的圆柱体、有限的方形棱柱和安装在屋顶上的烟囱。我想更好地了解尾迹产生体和局部流场之间的基本关系，以及近尾迹是如何受到物体形状、它与其他钝体的接近程度以及地平面的存在的影响的。对于安装在屋顶上的烟囱(“横流中的高空射流”)，我想更好地了解烟囱喷流流态如何影响烟囱所受的力和烟囱尾流中的流动。

"Bluff bodies" have non-streamlined shapes and very high drag coefficients. Flow around a bluff body is complex, and is characterized by a large region of separated flow, where the flow does not follow the shape of the body. In the low-pressure wake downstream of the body, which may be unsteady or turbulent, the phenomenon of "vortex shedding" occurs as vortices are periodically released from the surface of the body. Under certain conditions, vortex shedding may cause unwanted structural motion known as "flow-induced vibration." The main scientific goal of my research program is to advance the physical understanding of bluff-body wakes, where the emphasis is the flow around surface-mounted, finite-height bluff bodies, such as finite circular cylinders, finite square prisms, and rooftop-mounted chimney stacks. I want to better understand the fundamental relationships between the wake-generating body and the local flow field, and how the near wake is influenced by alterations to the body shape, its proximity to other bluff bodies, and the presence of the ground plane. For the rooftop-mounted stack (an "elevated jet in cross-flow"), I want to better understand how the stack jet flow regimes affect the forces experienced by the stack and the flow in the stack wake.