Applied Mechanics and Materials Vols. 479-480

Abstract: Some previous studies have demonstrated that electromagnetic valve (EMV), which uses permanent magnet and electromagnetic coil (PM/EM) hybrid actuator, has some benefits about actuator control, energy consumption, time response compared with conventional EMVs. In this paper, a new EMV with PM/EM actuator, which significantly differs from existing EMVs, has been proposed. The EMV design has been examined and analyzed by finite element. The results conclude that the EMV satisfies the requirement of dimension space limit. Moreover, the optimal EMV design meets the requirements of transition time and holding force. The holding force can reach about 719 N and drop 42.22% for valve releasing if desired current is supplied to the coils. Therefore, the EMV can fully control the closed and open of valve timings at maximum speed in SI engines.

Abstract: The main objective of this paper is to provide the methods and techniques to improve the design and manufacturing ability of electric scooter. The loads of some structure parts and the steering mechanism of the electric scooter are analyzed with RecurDyn. The stress distribution of steering mechanism and transmission mechanism can be calculated and performed with finite element analysis software. By using the computational ability and simulation of modern computer softwares, the factor of material fatigue can be found. The results of this research can be used to improve the design of electric scooter in the future.

Abstract: This study applies the finite element method (FEM) to predict maximum forging load and effective strain in bevel gear forging. Maximum forging load and effective strain are determined for different process parameters, such as modules, number of teeth, and die temperature of the bevel gear forging, using the FEM. Finally, the prediction of the power requirement for the bevel gear warm forging is determined.

Abstract: Ultrafiltration (UF) process has been widely used in many industrial applications to separate or concentrate macromolecular solution such as the making of fruit juice, the separation of oil-water emulsions, the treatment effluents from the pulp and paper, and environmental protecting applications. However, this process exhibits a limiting flux behavior caused by concentration polarization and consequently reduces the life of the membrane module. Concentration polarization can be especially severe in macromolecular solutions due to low diffusivity in membrane separation. In this study, we introduce an interrupted pulsatile flow to improve the performance of the membrane and decrease the concentration polarization layer. This method involves pulsing the feed flow discontinuously. Our results show that this method can be applied to membrane module regardless of it geometry and materials. Also, when comparing with un-pulsatile module, this could further leader to the improvement of membrane life. Keywords: ultrafiltation, interrupted - pulsating flow, concentration polarization, limiting flux behavior

Abstract: The porous aerostatic conveyor bearings are used to feed large substrates such as the flat panel display glass sheets and the silicon wafers by supporting them with compressed air in a non-contact condition. Due to unevenly distributed pressure in the air film between the substrate and the porous aerostatic conveyor bearing, the soft substrate often deforms and tilts on the bearing pad during the feeding process. In order to investigate the pressure distribution in the air gap, the CFD software, FLUENT, was employed to simulate the operation of the porous aerostatic conveyor bearing during the feeding process. In addition, the load capacity of the conveyor air bearing was calculated. The results show there is low vacuum pressure around the air discharge holes. The high pressure above the air supply holes forms two paraboloidal distributions in the air film. For design modification, the air supply and the air discharge holes need to be rearranged and/or relocated to improve the pressure distribution in the air film for more stable feeding of the substrate.

Abstract: The purpose of this study is to propose a new quadruped walking machine and investigate its dynamics. This paper first proposes a new quadruped walking machine and introduces its structure. The basic theory behind the equation of motion is briefly introduced. The dynamic characteristics of the walking machine, including the position, velocity, acceleration, support leg sequence, foot trajectory and pitch angle, are investigated and compared with the existing design. The results show that better transmission efficiency is achieved when the driving torque of the walking machine acts on the shaft of the crank. Compared to the existing design, the design proposed in this study has fewer changes in pitch angle during movement and exhibits less skidding while changing support leg.

Abstract: The aim of this paper is to analyze the magnetostatic field of disk-type permanent-magnet motors by utilizing the 1-D equivalent magnetic circuit approach and the finite-element method. A 1-D equivalent magnetic circuit model, which is analogous to an electric circuit model, of the disk-type permanent-magnet motor is proposed. The accuracy of the analytical model is verified by a commercial 3-D finite-element analysis (FEA) package. The result shows that the air-gap flux density is in good agreement with an acceptable error of about 1.66%. The presented magnetic circuit approach is not only an accurate technique in predicting the magnetostatic field of disk-type permanent-magnet motors, but also effectively reduces the computing time. It is especially suitable for the preliminary design and optimization of permanent-magnet motors with axial-flux topologies.

Abstract: Aerospace industry or manufacturing industries might demand high class more-axis CNC machine tools for the high accuracy needs for machining. The multiaxis CNC machine development in simulation of the new model application seems to be necessary for the market. The main purpose of this paper is to study the mechanisms of new model multiaxis CNC machine tools and build process to develop the characteristics of machine tools. Through the computer simulation and graphic animation, users can observe their relationships of each movement on the new model multiaxis CNC machine tools. Using ADAMS to realize the motion commands and coordinate the kinematics is proposed. The prototype demonstrates the feasibility and kinematics analysis of new model five-axis CNC for real machine.

Abstract: This study analyzes the flow flied and the guide vane associated with an in-line fan by an integrated numerical and experimental investigation. At first, the flow field associated with the fan is simulated by using a commercial CFD code Fluent with the finite volume method. In addition, the guiding vane profile is imposed and modified by examining characteristics of flow field. An appropriate guiding vane with high-performance and low-noise feature can be achieved after several design iterations. To manufacture the mock-up for experimental verification, the designed fan is expressed in the CAD/CAM format for the rapid-prototype technique. Moreover, a set of relations correlating the performance and noise of this fan prototype are executed with the aids of AMCA test chamber and semi-anechoic chamber, respectively. Consequently, the feasibility of design scheme and numerical system can be verified according to these experimental results. In summary, this work provides a systematic scheme for designing and analyzing the in-line fan.

Abstract: The accelerometer and gyroscope are used to identify the postural control disease as regards to the posturographic or sway analysis. For example, a gyroscope attached on the waist or head provides the several information such as sway area, sway velocity and others. However, prevalent methods did not describe the optimal position or reliable sensor for analysis. The purpose of this study is to observe and compare characteristics of accelerometers and gyroscopes according to attached positions because it can give the different results. We are assuming a pendulum model when the body sway, the 3-axis calibrated sensor accelerometer and gyroscope were attached on the different positions. From the experimental results, we have confirmed that the reliability of the accelerometers is depends on the position of the pendulum model contrast for the gyroscopes.