Gwo Chung Tsai

Transient Flow Analysis for Horizontal Axial Down-Wind Turbine

This study is to carry out a transient flow field analysis on the condition that the wind turbine is working to generate turbine, the wind turbine operating conditions change over time. Purpose of this study tries to find out the rule from the wind turbine changing over time. In transient analysis, the wind velocity on inlet boundary and rotation speed in the rotor field will change over time, and an analytical process is provided that can be used for future reference. At present, the wind turbine model is designed on the concept of down-wind horizontal axis type. The computer engineering software GH Bladed is used to obtain the relationship between the rotor velocity and the wind turbine. Then the ANSYS engineering software is used to calculate the stress and strain distribution in the blades over time. From the analytical result, the relationship between the stress distribution in the blades and the rotor velocity is got to be used as a reference for future wind turbine structural optimization.

Structural Analysis for the Blades of a Small Horizontal-Axis Wind Turbine

This study discussed the structural analysis of blades of a small horizontal-axis wind turbine (HAWT). The computational fluid dynamics (CFD) is combined with the computational solid mechanics (CSM) into the one-way fluid-solid interaction. The aerodynamic force calculated by CFD is loaded on the structure, and the structural deformation and stress distribution are calculated using CSM. The physical model in the study is a HAWT blade with the rated power output of 500 W, and the material is engineering plastics. The Youngs modulus of material is estimated according to the result of blade static load test. The accuracy of structural analysis is verified, and the blades in rated operating state are analyzed for fatigue failure. The blades in no-load running and rotor parked state are analyzed for ultimate strength. The blades of a wind turbine have large length-to-diameter ratio, and the structure approximates to a cantilever. The accuracy of linear analysis is good under a small load. However, as the load increases, the effect of geometric deformation should be considered to improve the precision of analysis. Therefore, the geometrical nonlinearity is used in this study to analyze the structure of blades in three operating states. The results showed that the safety of blades can meet the IEC 61400-2 international standard. In addition, the required safe distance between blades and tower is estimated at 157 mm according to the critical deformation analysis. According to the natural vibration modal analysis, the blades should be prevented from running at the rotating speed of 744 rpm that causes resonance for long.

Finite Element Analysis for Double Anterior Cruciate Ligament Reconstruction Analysis

This paper will take five male patients who performed a double-bundle anterior cruciate ligament (ACL) reconstruction to do finite element analysis and compare the stress distributions with each other. In order to lead this paper to reality, a model of the original bone tunnel according to CT is created and transformed into a finite-element model based on the reverse engineering method. The double-bundle ACL graft in the bone tunnel simulates the interference screw which screwed the ACL under the limit of friction and fix of contact. The dynamic analysis is performed with the femur flexion-extension axis which is under the limit of a fixed rotation angle (100°) and two degrees of freedom of motion in flexion. In the postprocess, the ACL graft is divided into several parts to get the stress distribution which will be easily to discuss the results. The result shows that max stress can be found on the top of the ACL or at the start point of the ACL because of the fixed position of the interference screw. The stress in PL bundle is greater than the stress in AM bundle. The angle of flexion will affect the stress and the stress might be higher at a specific angle.

Stress Analysis of Transmission System and Blade for Offshore Wind Power Generator

This article will perform the stress analysis of transmission system and tower of offshore wind power generator . It first utilizes the computer engineering software GH Bladed to get the load on the offshore wind power generator, then ANSYS software is used to get the stress distribution in the structure. From the analytical results, the stress distribution in the structure can be a basic data to perform a new design or strengthen the structure.

Impact Experiment and Analysis of the Carbon Fiber Composite Plate with the Central Hole

The composite material plate with the central hole is made by the composite prepreg. During the laying, the circle Teflon sheet is installed into the center of the composite plate. After curing, the center circle area was cut-out and the composite plate with the central hole was observed. Three different central holes are designed by the diameter of 12 mm, 14 mm, and 16 mm. The composite plate with central hole is stroke by the impact-or to measure the absorption energy, and acceleration to compare their impact resistance. The finite element analysis is also used to analyze the mechanical behavior of the plate during and after the impact. The results showed that the energy absorption capability is lower when the central hole became bigger.

13° Impact Test Analysis of Aluminum Alloy Wheel

Light alloy disc wheels are used in daily transportation very extensively, wheels need not only an artistic external, but an excellent performance that up to standard. According to Chinese National Standard-CNS 7135 [1], this paper study about 13° impact test by using finite element software – ANSYS, applying theory of elasto-plastic mechanics, and considering the effect of tire absorption. So we estimate the absorption percentage of tire effect in three cases, 0%, 20%, and 40%. By Reducing the striker kinetic energy to compensate for tire absorption, and after the analytic results compared with the experimental results, the analytic results can put to the proof.

CFD Analysis and Blade Optimization of a Small Horizontal Axis Wind Turbine

This paper aims to do blade design of a small horizontal axis wind turbine and perform wind tunnel test to conform its efficiency. In this research Bladecalculator, Pro/E and ANSYS/CFX are used to find the relationship between the blade rotating speed with torque. The analytical results of wind turbine completely match with that of test data. Comparison with data of generator, new design blade gets more power. The power of new design blades is about ten times as the original blades.

Stiffness and Nature Vibration Analyses of Linear Guideway Type

This study investigated the solution of the rigidity and structural vibration for system of linear guideway type based on ANSYS workbench. By comparing the results derived from the simulation of the model and the corresponding theoretical results, the validity of the theoretical solution can be verified. The analysis includes the system rigidity and the natural vibration frequency in the direction of vertical slider (Vertical), rolling (Rolling) and swing (Pitching), the structural vibration frequency for system of linear guideway type is carried out, the model is built according the true dimensions, what is more, the rollers are not necessary replaced by springs, because there is not so much difficulties by using ANSYS workbench and more accurate results can be obtained in this way. Two different types of simulation are carried out, and the simulation results show that different geometric sizes of slider, which mean different numbers of rollers, will change the resonance frequencies and mode shapes, and more rollers can enhance the stiffness of the LGT model, then reduce the possibility of resonance happening.

Kinematics Simulation and Optimization for the Mechanism of 5R-P

This study first establishes a mathematical model of 5R-P kinematics with the closed-loop vector method, then the corresponding M functions are written, at the same time, the 5R-P kinematic simulation model is built by virtue of Matlab/Simulink. From the simulation, the displacement, velocity and acceleration curves of slider can be obtained on condition that the appropriate initial conditions are set beforehand. Finally, Taguchi method is introduced to this mechanism to optimize the design of each link’s length, and a more reasonable combination of each link’s length allows the 5R-P mechanism to perform better. Most kinds of complicated linkages can be commonly designed in this method, which is parametrized more efficiently. What is more important is that this method can also be introduced to deal with the dynamic analysis of the linkages for the purpose of carrying out a more comprehensive design and optimization.

Direct Electro-Magnetic Mechanical Analysis of U-Shape Coil

This research to carry on the 3D model of electro-magnetic-mechanical forming analysis, its goal is lies in discusses the magnetic force which electric current produces the influence which creates to the plate, like distortion, stress and so on aspects. But before the analysis, establishes the 3D model first, in converges in ANSYS, gives the material parameter, the boundary condition and so on, then carries on the solution, subsequently obtains the analysis result. Knew by the analysis result, in approaches corner on the U shape coil dull position, its amount of deformation is the maximum value, and stress maximum value also in corner.