题目：Sensitivity of forces with respect to surface perturbations in fluid flow
报告人：Xuerui Mao（Durham University）
时间：2016年5月18日14：30
地点：流体力学楼C12-619学术报告厅
主办单位：国际合作交流处、科协、江苏省风力机设计高技术研究重点实验室、航空宇航学院
报告人简介：
Xuerui Mao, Lecturer of Turbomachinery and Fluid Mechanics, Durham University (DU), and going to be Associate professor of materials and manufacturing engineering, Nottingham University, Research in hydrodynamic stability, flow control, stratification of atmosphere boundary layer; dynamic modal decomposition; flow induced deformation of flexible structures; offshore wind energy; computational acoustics; high-order finite element methods. Published 27 papers on journals including Journal of Fluid Mechanics and AIAA Journal.
报告简介：
The sensitivity analysis in fluid dynamics was mainly targeted at the most energetic noise and the induced instability and laminar-turbulence transition. This established methodology is extended to calculate the sensitivity of forces in unsteady flow past a solid body to active, passive and mixed boundary perturbations, all of which are extensively studied in flow control, stability and receptivity investigations. Active perturbations refer to velocity fluctuations on the body surface and involve an energy input; passive perturbations refer to the change of body surface and represent surface roughness; mixed perturbations are the combination of the other two and represent dynamic roughness or surface vibrations. The sensitivity of forces to the three perturbations can be evaluated in the same framework through a continuous adjoint method, which requires the full history of the unperturbed flow. The magnitude of the sensitivity represents the controllability of the flow while the distribution of the sensitivity can be scaled as a control. The algorithms are further applied to two-dimensional and three-dimensional bluff body flow and boundary layer flow.
