风荷载是输电线路设计的主要控制荷载,规范中导地线风荷载计算采用了风荷载调整系数,但规范并未给出物理含义。以风工程理论为基础,推导了导地线风振系数计算公式,并选取参数进行了风振系数计算,将计算结果与中国规范、ASCE 74、BS EN 5...风荷载是输电线路设计的主要控制荷载,规范中导地线风荷载计算采用了风荷载调整系数,但规范并未给出物理含义。以风工程理论为基础,推导了导地线风振系数计算公式,并选取参数进行了风振系数计算,将计算结果与中国规范、ASCE 74、BS EN 50341和IEC 60826的风振系数进行比较,结果表明:推导公式的风振系数与国外规范规定数值比较接近,中国线路规范导地线风荷载计算未考虑脉动风影响,导致其计算结果偏不安全。展开更多
Owing to the advantages of wire-driven parallel manipulator, a new wire-driven parallel suspension system for airplane model in low-speed wind tunnel is constructed, and the methods to measure and calculate the aerody...Owing to the advantages of wire-driven parallel manipulator, a new wire-driven parallel suspension system for airplane model in low-speed wind tunnel is constructed, and the methods to measure and calculate the aerodynamic parameters of the airplane model are studied. In detail, a static model of the wire-driven parallel suspension is analyzed, a mathematical model for describ- ing the aerodynamic loads exerted on the scale model is constructed and a calculation method for obtaining the aerodynamic parameters of the model by measuring the tension of wires is presented. Moreover, the measurement system for wire tension and its corresponding data acquisition system are designed and built. Thereafter, the wire-driven parallel suspension system is placed in an open return circuit low-speed wind tunnel for wind tunnel tests to acquire data of each wire tension when the airplane model is at different attitudes and different wind speeds. A group of curves about the parameters for aerodynamic load exerted on the airplane model are obtained at different wind speeds after the acquired data are analyzed. The research results validate the feasibility of using a wire-driven parallel manipulator as the suspension system for low-speed wind ttmnel tests.展开更多
文摘风荷载是输电线路设计的主要控制荷载,规范中导地线风荷载计算采用了风荷载调整系数,但规范并未给出物理含义。以风工程理论为基础,推导了导地线风振系数计算公式,并选取参数进行了风振系数计算,将计算结果与中国规范、ASCE 74、BS EN 50341和IEC 60826的风振系数进行比较,结果表明:推导公式的风振系数与国外规范规定数值比较接近,中国线路规范导地线风荷载计算未考虑脉动风影响,导致其计算结果偏不安全。
基金National Natural Science Foundation of China (50475099)
文摘Owing to the advantages of wire-driven parallel manipulator, a new wire-driven parallel suspension system for airplane model in low-speed wind tunnel is constructed, and the methods to measure and calculate the aerodynamic parameters of the airplane model are studied. In detail, a static model of the wire-driven parallel suspension is analyzed, a mathematical model for describ- ing the aerodynamic loads exerted on the scale model is constructed and a calculation method for obtaining the aerodynamic parameters of the model by measuring the tension of wires is presented. Moreover, the measurement system for wire tension and its corresponding data acquisition system are designed and built. Thereafter, the wire-driven parallel suspension system is placed in an open return circuit low-speed wind tunnel for wind tunnel tests to acquire data of each wire tension when the airplane model is at different attitudes and different wind speeds. A group of curves about the parameters for aerodynamic load exerted on the airplane model are obtained at different wind speeds after the acquired data are analyzed. The research results validate the feasibility of using a wire-driven parallel manipulator as the suspension system for low-speed wind ttmnel tests.
