Papers by Author: Bo Wun Huang

Abstract: Due to the rise of biological and MEMS technology in recent years, some micro flow system components have been paid attentions to developed by many investigators. The importance of micro-pumps manufactured is higher than the other part of micro flow system since it is the power source of the entire micro-flow system and responsible for driving working fluid in the microfluidic system. In actual operation, the instability and bad dynamic characteristics of the micro-pump will cause larger fluid flow mobility error, such as transport behavior and response procedures failure, etc., and even damage the microfluidic system. Therefore, to investigate the stability and dynamic characteristics of a micro pump is necessary. The miniature piezoelectric film micro-pump, made by Microjet Technology Co., Ltd., is employed to study in this work. The computer graphics software SolidWorks is used to build the model of the micro pump. Then, The Finite element analysis (FEA), ANSYS Workbench, is also employed to analyze the dynamic characteristics of this micro pump.

Abstract: Finite element analysis on natural properties of a micro drill with ultrasonic vibration is considered to study. Because getting smaller aperture in the printed circuit board (PCB), it tends to be more severe due to vibration. The vibration has adverse effects to machining accuracy and surface roughness which will increase tool abrasion and further accelerate the destruction from material fatigue. There are many ways to produce perforations, such as laser micro-machining and micro-drilling. The industry still adopts micro drill piercing process due to the cost and technical considerations. In order to enhance the cutlery life and the quality of the drilling process, the cutting characteristic of bur is important. Hence, the vibration during drilling must be suppressed. This study is to investigate the natural properties of a micro drill under ultrasonic vibration (50 kHz) excited with a piezoelectric-driven actuator and numerically by using finite element analysis.

Abstract: Sun intensity and angle on efficiency of solar cell System is considered to study. Solar energy is a clean, non-polluting and renewable resource; it uses the photovoltaic effect to convert sunlight into a free and available energy source. However, solar energy output is highly affected by the temperature and intensity of sunlight. As the temperature of the solar module rises, energy output will decrease, if the intensity of sunlight is stronger, there will be more output energy. With adequate heat sink and proper ventilation, a module’s temperature will be decreased, and also increase output energy. This study uses 10 kilowatt grid-connected photovoltaic system and a solar tracker to measure the direction of the sun, to find out the relationship between solar intensity and angle effects on energy output.

Abstract: Viscoelastic damping isolator (VDI) is a new way to reduce the vibration of punch press in automobiles, motorcycles, IT, aerospace, mold and other industries. It not only reduces the vibration of large punching machine and equipment, but also decreases its maintenance costs and avoids endangering the surrounding environment. VDI is composed of partitions, damping fluid, steel springs and level adjusters. Different number of the partitions are welded on upper and lower rectangular steel plates, respectively. Steel springs are placed at the edges between the plates to support up to 150 tons of weight of the punch press. Screw level adjusters are place between lower and thick bottom plates to adjust the horizontal level of the isolator. The damping fluid is filled in the space between interlacing partitions approximate 60% of the height of the composed isolator. The impact energy produced by the presser is dissipated by shear deformation between the damping fluid and partitions. This article used 3D graphing software and finite element method (FEM) to investigate the dynamic characteristic of the damping isolator after impacted by the puncher. The normal mode analysis of the VDI is obtained. The isolator is settled within 0.3 seconds after 300,000 N shock impact and satisfies industrial specification of large punchers with loading frequency of 100 cycle/min.

Abstract: In recent years, microdrill becomes a very important element in the process of drilling apertures of PCB integrated circuits. But different material property will often generate collapse or fracture of the drill tip. This study is about to establish a finite element model (FEM) and to get the buckling stress analysis of the microdrill by ANSYS software. Since the microdrill is a structural brittle material and easy to be broken, force over buckling critical load is employed to explore the structural weakness and to analyze its stress damage. In addition, vibration, occurred at high-speed micro drilling, could easily lead to the excessive deflection or feeding amount of the drill tip, cause the collapse or rupture of the microdrill, and lower the quality by reaming the machining object. Poor geometric aspect ratio of the drill tip will generate different loads in different parts. How to manage the pressure for the microdrill to apply the force stably and to avoid the breakage and destruction is very important both for the tool life and the cost control. Therefore, how to overcome the buckling of tiny structure component under loading becomes a great issue to be explored.

Abstract: Hydrogen energy fuel cell is one of the clean/green energy solutions for the environmental pollution, global warming, and petroleum energy shortage. This study investigates the dynamic characteristic of the green hydrogen energy fuel cell: Proton Exchange Membrane Fuel Cell (PEMFC). PEMFC has been adopted to be the power supplier of the vehicle, small train, etc. A lot of researchers aim on pure electrical property analysis. However, to put PEMFC power system on the road, some mechanical properties of the system should also been examined. In this paper, the dynamic characteristic of a single PEMFC is studied. A single PEMFC (L112×W82×D6 mm) is set up and measured for the time and frequency response. Several fundamental modes are found experimentally which should be avoid during operation period of PEMFC especially in a moving vehicle.

Abstract: Vibration of a tube with the fluid and axial load is focused. In a heat exchanger, the tubes are frequently affected by external force and fluid shock waves. Thus, tubes are often found to be vibrated. This vibration may alter the performance of the tubes and global heat exchanger. That a heat exchanger system is weakly coupled as the each tube is coupled to the adjacent one through the fluid is found. To understand the global system dynamics, the dynamics of a tube must be investigated first. In this work, the dynamic properties of a tube with the axial loads are investigated. The Galerkin method employed, the equation of a tube with the fluid effect can be to derive. Numerical results reveal that the axial load and fluid effects may affect the dynamic properties of a tube with fluid significantly.

Abstract: An investigation of the residual vibration of a round tapered hollow metal beam is considered in this article. To improve the tapered hollow metal beam performance and capabilities, it is necessary to understand the dynamic characteristics, residual vibration, of this above Beam. The properties of a tapered hollow beam bring about some investigations to study. It attempt to design and manufacture a high performance sporting ball rod. More high precision and performance sporting ball rod require more stable, small residual vibration. Besides, most important of all, a small residual vibration sporting rod results in the stable sweeping and comfortable sporting for a sportsman. To design and manufacture a high performance sporting ball rod, the dynamic characteristic and residual vibration must be study. Most investigations pay attentions to the sweeping, damper and material properties. Few studies focus on dynamic characteristics and residual vibration of a tapered hollow beam. It is the aim to study in this article.

Abstract: This paper studies the elevated-temperature sweep characteristics of wire bond during transfer molding process for semiconductor package. A set of sweep experiments is also conducted to acquire the sweep stiffness of wire bond for several bond spans and bond heights. The results show the increase of the sweep deflections is more delicate to bond span than bond height. The main objectives of this research are to obtain elevated-temperature material properties of gold wire experimentally and to predict the wire sweep of various bond spans and bond heights subjected to drag force in the compound flow during transfer molding. Based on the analysis results of ANSYS, the effects of bond span and bond height on wire sweep in the elevated-temperature environment can be obtained. Then, the elevated-temperature deflections of wire sweep can be predicted.