Spiral Magnus is a unique wind turbine system that rotates with cylinders which have spiral-shaped fins coiled around them （instead of using the more common propeller-type blades）. In the present study, three models...Spiral Magnus is a unique wind turbine system that rotates with cylinders which have spiral-shaped fins coiled around them （instead of using the more common propeller-type blades）. In the present study, three models （cylinder with no fins, cylinder with straight fins and cylinder with spiral fins） were installed, and fluid force measurements were performed by a strain gauge force balance. A PIV （particle image velocimetry） system was used to better understand the flow fields around the cylinder. Considering the results of the experiment, it was confirmed that, the aerodynamic performance of the rotating cylinder can be improved by the fin. However, the straight fin makes the flow close to the cylinder surface ineffective. The rotary cylinder with the spiral fins was able to generate the greatest lift among three models, because the spiral fin effectively influences the vicinity of the cylinder surface.展开更多
Based on the critical gap phenomenon of the intestinal capsule robot,a variable-diameter capsule robot with radial gap self-compensation is developed in this paper.With the functional variation principle,a fluid dynam...Based on the critical gap phenomenon of the intestinal capsule robot,a variable-diameter capsule robot with radial gap self-compensation is developed in this paper.With the functional variation principle,a fluid dynamic pressure model satisfying the boundary conditions of the outer surface of capsule robot with screw blades is derived.The critical gap phenomenon is studied theoretically and experimentally based on the end effect and the dynamic balance characteristics of the fluid on the surface of capsule robot.The concept of start-up rotation speed is defined,the relationship between the start-up rotation speed and the spiral parameters of capsule robot is investigated.The strategy for implementing drive and control on several capsule robots under the same rotational magnetic field is proposed,and by defining the start-up curves of several capsule robots with the similar motion regulation as the objective functions,genetic algorithm is employed to optimize the spiral parameters of several capsule robots.Experiments have shown that the proposed drive and control strategy for several capsule robots can be implemented effectively.It has a good prospect of application inside intestine to realize the drive and control on several capsule robots for different medical purposes.展开更多
文摘Spiral Magnus is a unique wind turbine system that rotates with cylinders which have spiral-shaped fins coiled around them （instead of using the more common propeller-type blades）. In the present study, three models （cylinder with no fins, cylinder with straight fins and cylinder with spiral fins） were installed, and fluid force measurements were performed by a strain gauge force balance. A PIV （particle image velocimetry） system was used to better understand the flow fields around the cylinder. Considering the results of the experiment, it was confirmed that, the aerodynamic performance of the rotating cylinder can be improved by the fin. However, the straight fin makes the flow close to the cylinder surface ineffective. The rotary cylinder with the spiral fins was able to generate the greatest lift among three models, because the spiral fin effectively influences the vicinity of the cylinder surface.
基金supported by National Natural Science Foundation of China(Grant Nos. 60675054, 60875064)Self-Planned Task of State Key Laboratory of Robotics and System (HIT) (Grant No. SKLRS200903B)
文摘Based on the critical gap phenomenon of the intestinal capsule robot,a variable-diameter capsule robot with radial gap self-compensation is developed in this paper.With the functional variation principle,a fluid dynamic pressure model satisfying the boundary conditions of the outer surface of capsule robot with screw blades is derived.The critical gap phenomenon is studied theoretically and experimentally based on the end effect and the dynamic balance characteristics of the fluid on the surface of capsule robot.The concept of start-up rotation speed is defined,the relationship between the start-up rotation speed and the spiral parameters of capsule robot is investigated.The strategy for implementing drive and control on several capsule robots under the same rotational magnetic field is proposed,and by defining the start-up curves of several capsule robots with the similar motion regulation as the objective functions,genetic algorithm is employed to optimize the spiral parameters of several capsule robots.Experiments have shown that the proposed drive and control strategy for several capsule robots can be implemented effectively.It has a good prospect of application inside intestine to realize the drive and control on several capsule robots for different medical purposes.
