Papers by Author: Ying Xue Yao

Abstract: Duck wave energy converter has the advantages of high conversion efficiency, simple construction, low cost relative to other wave power device. In the paper, the numerical simulation of the response of the converter was calculated by the AQWA software which based on the three dimensional potential flow theories. The results show that the pitch angle appear the peak when the incident wave frequency is 1rad/s and the maximum of the pitch angle come out as the linear wave normally incident the duck body, which means duck wave energy converter can absorb more wave energy in this angular frequency. The above research can provide reference for the design of the duck wave energy converter.

Abstract: A tool path planning algorithm that generates contour-parallel tool paths for 2D pockets is proposed. 2D pockets with islands bounded by line and arc segments can be handled. The algorithm first generates raw offset loops by vertex offset, then based on the concepts of offset region and invalid edge, local invalid edges are removed. By the character of direction vectors at the intersections of offset tool paths, the invalid sup-loops are removed. The offset tool paths are linked by depth-first traversal algorithm after constructing a single-parent tree. Experimental results are given to verify the proposed algorithm.

Abstract: The DGZX - 1425 high-speed milling motorized spindle which is made and designed independently by Hao Zhi electrical and mechanical company in Guangzhou China is made as the research object, the method of establishing numerical simulation model for the spindle units dynamic performances is established, and the design of the spindles structure has been verified reasonable. Modal analysis of the spindle has been completed in ANSYS Workbench to get the first six natural frequencies and mode shapes. Harmonic analysis of the spindle is also completed to obtain the dynamic stiffness at the highest speed. Modal test and vibration test of the assembled spindle are also processed, which have verified the accuracy of the finite element method. The paper has provided a theoretical basis for the motorized spindles design, structural optimization and the improvement of the dynamic performances.

Abstract: The method of texting a blade’s aerodynamic performance used for traditional wind turbine airfoils was making pressure measurement holes on surface of the blade, but Magnus wind turbine blade must rotated at a certain speed to generate lift and drag force, so the method was inapplicable. A novel experimental device for testing aerodynamic performance of Magnus wind turbine’s cylindrical blades had been investigated. This device, which consists of three parts: cylindrical blade, controlling system and testing system, could measure the lift and drag force generated by the Magnus effect on the blades. This paper mainly studied the testing system,including dynamometer and amplifying circuit. At last, the testing system was used in the experiment to test aerodynamic performance of the Magnus wind turbine blade. The results showed that the system could conduct the experiment on testing the lift and drag force on the Magnus wind turbine blades efficiently, and the system could also be used to measure the lift and drag force on traditional wind turbine airfoil.

Abstract: A low-speed spindle running on air bearings is presented, it is used on rotary viscometer based on velocity attenuation of rotating cylinder. Principle of spindle is introduced, it is composed of a low speed motor and an air bearing. The low speed motor is a coupling of two motors. Design of the spindle shows the structure of it. Materials of the spindle are selected. The spindle is machined and operation process of it shows it is suitable for driving part of rotary viscometer based on velocity attenuation of rotating cylinder.

Abstract: This paper analyzed the advantages of traditional Savonius (S-type) turbine and the reasons of its low efficiency, proposed a new type of turbine with self-rotating blades and surrounded by a rectifier, and studied the aerodynamic performance by numerical simulations. The turbine is composed of a rectifier and a rotor, the rectifier consists by straight and arc segments which can accelerate the wind speed and adjust the inflow wind angle. The self-rotating blade can reduce the impacted area acting on the leeward blade by wind and arm of the impact torque, therefore reduces the resistant torque of the blade, and the driving torque acting on the windward blade is almost the same with traditional S-type turbine, which can increase the overall driving torque. The result shows that the new turbine has the advantages as below: wide range of wind speed for effective working, high power coefficient (Cp), suitable for low wind speed aera etc. Although the flow field in S-type turbine is complex separating flow, the performance of the turbine proposed in this paper is improved and is better than traditional S-type turbine in numerical simulation which is worth for spreading.

Abstract: This paper summarizes the research results of the structural parameters which have effects on the performance of Savonius wind turbine. Savonius wind turbine being used in wind power and tidal power belongs to vertical axis wind turbine (VAWT). Recently, more and more research have placed on it for its advantages such as: being able to accept wind from any direction, long fatigue life of the blades, high starting torque, wide working wind speed range, easy to install, manufacture and maintain and low noise etc. The performance of Savonius wind turbine is affected by many factors. Different structural parameters can bring huge differences in turbine performance. Especially the differences in the maximum wind energy utilization (Cp-max) can be more than 30% with different structure. Many new turbines get higher Cp-max by improving the structural parameters. In this paper, the structural improvement information of Savonius wind turbine is summarized in order to provide useful knowledge for the researchers in the structural design and improvement.

Abstract: Particle reinforced metal matrix composites (SiCp/Al composites) have proved to be extremely difficult to machine with traditional cutting processes due to serious tool-wear and high machining cost, which lead to the low machining efficiency. This paper presents the results of an experimental research on mill-grinding of SiC particle reinforced aluminum matrix composites. Based on the Taguchi experimental design method, study on the material removal rate was carried out to gain the optimal processing parameters combination by using the analysis of S/N ratio. The detailed effect of wheel speed on material removal rate through single factor experiment was also studied. Though analysis of S/N ratio and variance, the depth of cut has greatest effect on the material removal rate, followed by feed rate. And grinding wheel speed has least effect on it. But the depth of cut and feed rate affect on the material removal rate nonlinearly. In the range of machining parameters applied, the optimal processing parameters combination gained is A2B3C3, namely, v_s=11.77m/s, v_w=100mm/min, a_p=0.8mm. Material removal rate increased at first and then there was a decreasing trend with increasing wheel speed.

Abstract: This paper explains and demonstrates the machinability of dry and wet machining of SiC particle-reinforced aluminum metal matrix composites based on the experiments. The plunge surface experiments with mill-grinding method under wheel peripheral speed of up to 14.13m/s, feed rate 80mm/min and depth of cutting 50μm were carried out on a vertical CNC milling machine. The comparisons of dry and wet machining on the force composites and surface roughness (Ra) versus material removal volume were studied. The material removal volume was gained with the same machining parameters after an equal period of time. In most cases, the tangential mill-grinding force values are greater in wet machining condition than that in dry condition. But for normal mill-grinding force, the Fn values are much greater in dry machining condition than that in wet condition. And the normal mill-grinding force in wet machining increased quickly with increasing material removal volume. A better surface finish can be produced in dry machining than that produced by wet machining. The surface roughness decreased slowly with the increasing material removal volume and the surface roughness shows an insignificant decreasing trend in wet machining.

Abstract: Uniform molten metal droplet stream from jet break-up provides potential technology for metal parts rapid prototype manufacturing. In this study an experimental device capable of producing uniform metal droplet stream has been developed. Monosize spherical powders of 180m in diameter can be obtained after cooling and solidification. Then the droplets were electrostatically charged and deflected during flight to deposit onto a revolving substrate to form a 3D metal part.