Deep understanding on the impacts of leading edge erosion on the performance and flow characteristics of wind turbines is significant for the blade design and wind farms management. Pitting erosion and three levels of delamination are considered in the present study. The results show that the degrees of leading edge erosion have great influence on the flow separation, tangential force coefficient, normal force coefficient as well as the power output of the wind turbine. Leading edge erosion has the greatest impact on aerodynamics of the wind turbine at 15 m/s, where the maximum loss in the power output can reach up to 73.26%.

Abstract. In order to test the dynamic characteristics of the shock test bed for gun breechblock system expediently, the dynamic model was established based on the virtual prototype technology. The three-dimensional solid model of each part was established and assembled by software Pro/Engineer. Then the whole model was imported into the dynamic software MSC.ADAMS through the interface, Mechanism/Pro, between the two software. Then the constraints, contacts or spring force between each two parts were added in the model according to the relation in practice. The force outside was imposed on the bearing part. After that, the virtual prototype model was established. With the model, simulation was processed and the dynamic characteristics of the parts of the shock test bed were tested under different conditions. The test results show that the model is tallies with the physical prototype and can be used to analyze the dynamic characteristics of the shock test bed parts.

Abstract. For it is hard to develop experiments for the gun breechblock system, a shock test bed is designed for it. During designing, the breechblock operating force is one of the key test parameters of the shock test bed for gun breechblock system. In order to choose a reasonable value to open breechblock, influence of breechblock operating force on breechblock operating works of shock test bed is analyzed. With the design principle determined, the dynamics principle model of the shock test bed is established based on the virtual prototype technology. According to the minimum theoretical force F, a standard value for shock test bed to open breechblock. As both the mass of breechblock operating cam and the breechblock operating distance are fixed, the simulation experiments are performed based on the principle model when the breechblock operating force is F, 1.5F, 2F, 2.5F and 3F separately. The results show that the greater breechblock operating force is, the more total work, useful work and useless work have been done. But the wasted energy of work will increase. By the research, it is better to choose a less value of breechblock operating force.