There are amounts of issues to be resolved in the process of designing the fiber placement trajectory of the cylindrical component,such as the interference between the machine and the component and the over-travel of ...There are amounts of issues to be resolved in the process of designing the fiber placement trajectory of the cylindrical component,such as the interference between the machine and the component and the over-travel of the axis of rotation on the fiber placement head.When the pressure on the cylinder surface inclines in a certain direction or at an angle within the normal plane,the motion characteristics of the rotation axis will be different.This paper analyzes the pressure angle effect of the concave cylinder surface on the motion features of a fiber placement machine.The placement area is enlarged by tilting pressure with the same lifting stroke,which is significant in preventing interference and selecting post-processing algorithm.展开更多
The turbulent wakes behind trailing edge are analyzed for understanding of the flow mechanisms responsible for the generation of trailing edge noise. The TILS （turbulence integral length scale） of the turbulent wake...The turbulent wakes behind trailing edge are analyzed for understanding of the flow mechanisms responsible for the generation of trailing edge noise. The TILS （turbulence integral length scale） of the turbulent wake of hydrofoil with blunt trailing edge is calculated from TR-PIV （time-resolved particle image velocimetry） data. The temporal auto-correlation method based on Taylor hypothesis and spatial correlation method are used to get the TILS information of the turbulent wake of hydrofoil, respectively The comparison of results by two methods indicates that the spatial correlation method is independent on Taylor hypothesis and suitable to strong turbulence and non-isotropic turbulence.展开更多
基金supported by the Equipment Development Department Project of China(No. 41422010401)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘There are amounts of issues to be resolved in the process of designing the fiber placement trajectory of the cylindrical component,such as the interference between the machine and the component and the over-travel of the axis of rotation on the fiber placement head.When the pressure on the cylinder surface inclines in a certain direction or at an angle within the normal plane,the motion characteristics of the rotation axis will be different.This paper analyzes the pressure angle effect of the concave cylinder surface on the motion features of a fiber placement machine.The placement area is enlarged by tilting pressure with the same lifting stroke,which is significant in preventing interference and selecting post-processing algorithm.
文摘The turbulent wakes behind trailing edge are analyzed for understanding of the flow mechanisms responsible for the generation of trailing edge noise. The TILS （turbulence integral length scale） of the turbulent wake of hydrofoil with blunt trailing edge is calculated from TR-PIV （time-resolved particle image velocimetry） data. The temporal auto-correlation method based on Taylor hypothesis and spatial correlation method are used to get the TILS information of the turbulent wake of hydrofoil, respectively The comparison of results by two methods indicates that the spatial correlation method is independent on Taylor hypothesis and suitable to strong turbulence and non-isotropic turbulence.
