Fast statistical methods of interconnect delay and slew in the presence of process fluctuations are proposed. Using an optimized quadratic model to describe the effects of process variations, the proposed method enabl...Fast statistical methods of interconnect delay and slew in the presence of process fluctuations are proposed. Using an optimized quadratic model to describe the effects of process variations, the proposed method enables closedform expressions of interconnect delay and slew for the given variations in relevant process parameters. Simulation results show that the method, which has a statistical characteristic similar to traditional methodology, is more efficient compared to HSPICE-based Monte Carlo simulations and traditional methodology.展开更多
This study investigates the effects of a novel passive flow control mechanism,a flexible leading edge(LE),on the aerodynamic performance of a NACA 0018 airfoil and a scaled vertical axis wind turbine(VAWT)model.Wind t...This study investigates the effects of a novel passive flow control mechanism,a flexible leading edge(LE),on the aerodynamic performance of a NACA 0018 airfoil and a scaled vertical axis wind turbine(VAWT)model.Wind tunnel experiments were conducted on 2D airfoil sections under steady flow and dynamic pitching conditions,and a scaled VAWT model was tested in an open-field environment.The flexible LE airfoil demonstrated significant improvements in delaying static stall angles and enhancing lift generation during dynamic pitching by inducing earlier and prolonged high suction pressures.The scaled VAWT model with flexible LE blades showed increased rotational speeds and higher voltage outputs compared with the rigid blade VAWT,particularly at higher wind speeds.Both rotational speed and electrical voltage data suggest that the flexible LE structure enhances the aerodynamic efficiency of the VAWT.The findings suggest that the flexible LE structure is an efficient and cost-effective method to improve VAWT aerodynamic efficiency.展开更多
文摘Fast statistical methods of interconnect delay and slew in the presence of process fluctuations are proposed. Using an optimized quadratic model to describe the effects of process variations, the proposed method enables closedform expressions of interconnect delay and slew for the given variations in relevant process parameters. Simulation results show that the method, which has a statistical characteristic similar to traditional methodology, is more efficient compared to HSPICE-based Monte Carlo simulations and traditional methodology.
文摘This study investigates the effects of a novel passive flow control mechanism,a flexible leading edge(LE),on the aerodynamic performance of a NACA 0018 airfoil and a scaled vertical axis wind turbine(VAWT)model.Wind tunnel experiments were conducted on 2D airfoil sections under steady flow and dynamic pitching conditions,and a scaled VAWT model was tested in an open-field environment.The flexible LE airfoil demonstrated significant improvements in delaying static stall angles and enhancing lift generation during dynamic pitching by inducing earlier and prolonged high suction pressures.The scaled VAWT model with flexible LE blades showed increased rotational speeds and higher voltage outputs compared with the rigid blade VAWT,particularly at higher wind speeds.Both rotational speed and electrical voltage data suggest that the flexible LE structure enhances the aerodynamic efficiency of the VAWT.The findings suggest that the flexible LE structure is an efficient and cost-effective method to improve VAWT aerodynamic efficiency.
