Taiwan Association of Engineering and Technology Innovation: E-Journals
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Design and Analysis of a Water Channel for Characterization of Low Reynolds Number Flows
Get PDFA water channel for performing flow visualization and studying scale models in fluid mechanics was designed, analyzed, and manufactured with commercially available components. The material cost of the channel is 10% of the leading educational units, and the manufacturing processes required for channel construction are basic and typical of local craftsmen in developing countries.Both structural analysis and flow rate calculations were performed to verify the functionality of the tunnel. Hand calculations and Finite Element Analysis were used to model stress and deflection in the channel floor under hydrostatic loads. These were used to select a polycarbonate panel thickness that will withstand the hydrostatic and hydrodynamic loads on the channel floor and walls for a projected useful lifespan of 40 years.The water channel has a test section area that is 30 cm by 42 cm and up to 1 m long. The system pump is capable of generating incident flows of up to 7.1 cm/sec in the test section. The channel is also designed to be upgraded with a tow carriage, allowing for flow visualization as well as fully submerged and partially submerged models with Reynold’s or Froude’s number dependent studies
A Study on Aluminum Pad Large Deformation during Copper Wirebonding for High Power IC Package
Get PDFIn this paper, a 3-D finite element prediction on aluminum pad squeeze during copper wirebonding process for high power IC package is presented. ANSYS Parametric Design Language (APDL) has been implemented on modelling, mesh density, boundary condition (BC), impact stage and contact mode for first bond process. The ANSYS/LS-DYNA solver is applied to solve dynamics and LS-PREPOST is used to observe the predicted large plastic deformation on bond pad and stress on microstructure under pad. In view of high power IC package, larger diameter of copper wire is required for electric loading for its low cost. In this research, a large diameter of 2 mil (50 um) uncoated pure copper (4N) wire is applied to simulate first bond impact-contact process. As the scale double enlarged, the problems encountered in simulation are usually evident. Preliminary results on impact stage demonstrate that negative volume/hourglass on large distortion can be solved by tune-up inertial contact settings and mesh density. However, sever hourglass defect would occur on ultrasonic stage and remain a pending problem. A series of prediction has been conducted on first bond process during impact stage and the results can then be applied to the dynamic wirebonding assembly process
Investigation of Slug Flow Characteristics for Energy Harvesting Applications
Get PDFThe purpose of this research work is to study the characteristics of air-water slug flow for energy harvesting applications. It involves an investigation and analysis of the liquid hold-up, slug frequency and the translational velocity from conductivity rings. The experimental test was carried out with a different flow rate of the air-water slug flow in 2-inch rig horizontal pipe using a ring type conductance probe. The conductivity rings were used to obtain the slug flow characteristics. Forces were generated as a result of the fluctuating pressure of the slug flow on the entire cross-sectional area of the pipe. The acquired signal of the pressure fluctuation was used to simulate the expected outcome. The result shows that a maximum forward slug force of 30N per cross-sectional area of the pipe was obtained and 26N force of the fluctuating pressure through the cross-section was generated at the flange-end. The obtained forces can be applied to using electromagnetic or piezoelectric harvester to generate the electrical output in order to energize electro-mechanical devices
Distributed Database Semantic Integration of Wireless Sensor Network to Access the Environmental Monitoring System
Get PDFA wireless sensor network (WSN) works continuously to gather information from sensors that generate large volumes of data to be handled and processed by applications. Current efforts in sensor networks focus more on networking and development services for a variety of applications and less on processing and integrating data from heterogeneous sensors. There is an increased need for information to become shareable across different sensors, database platforms, and applications that are not easily implemented in traditional database systems. To solve the issue of these large amounts of data from different servers and database platforms (including sensor data), a semantic sensor web service platform is needed to enable a machine to extract meaningful information from the sensor’s raw data. This additionally helps to minimize and simplify data processing and to deduce new information from existing data. This paper implements a semantic web data platform (SWDP) to manage the distribution of data sensors based on the semantic database system. SWDP uses sensors for temperature, humidity, carbon monoxide, carbon dioxide, luminosity, and noise. The system uses the Sesame semantic web database for data processing and a WSN to distribute, minimize, and simplify information processing. The sensor nodes are distributed in different places to collect sensor data. The SWDP generates context information in the form of a resource description framework. The experiment results demonstrate that the SWDP is more efficient than the traditional database system in terms of memory usage and processing time
MFO Ptimized Fractional Order Based Controller on Power System Stability
Get PDFThis paper presents a novel idea of designing the Fractional-Order PID (FOPID) type static synchronous series compensator (SSSC). A power system stabilizer(PSS) is installed to enhance the system transient stability by damping the oscillations. Also, the superiority of the proposed method is verified by comparing with conventional PI, PI-PD and PID controllers. The determination of the controller parameters has been considered as an optimization problem using Moth Fly Optimization (MFO). It is shown that MFO is more effective as well as giving robust response than Differential Evolution (DE) optimization. The superiority of the controller is tested on Single-Machine Infinite-Bus (SMIB) power system at various operating conditions and fault locations
A Study on the Development of Game-based Mind Wandering Judgment Model in Video Lecture-based Education
Get PDFAlthough video lecture materials are very efficient learning materials, they are likely to be unilateral learning materials by the lecturer. It is easily degraded to be one-sided learning, which has been considered as a problem of online education, and it is difficult to judge whether learners are actually learning. Therefore, in this paper, a minimum learning activity judgment model that can automatically determine if they actually learn through mind wandering judgment was proposed to overcome the limitations of previous learning materials, and educational effect verification experiment was performed. Experiment results show that the video lecture class using the minimum learning activity judgment system was effective in improving the academic achievement
Energy-effective Predictive Temperature Control for Soy Mash Fermentation Based on Compartmental Pharmacokinetic Modelling
Get PDFCompartment modelling has been successfully used in pharmacokinetics to describe the kinetics of drug distribution in body tissues. In this study, the technique is adopted to describe the dynamics of temperature response and energy exchange in a soy mash fermentation system. The objective is to provide a precise temperature-controlled atmosphere for effective fermentation with the premise of energy saving. In analogy to pharmacokinetics, water and mash tanks are treated as compartments, energy flow as drug delivery, and the temperature as the drug concentration in a specific compartment. The model allows us to estimate the time of injecting a certain amount of energy to a specific tank (compartment) in a cost-effective way. Thus, model-based temperature control and energy management can be possible
Flowfield Analysis of a Pneumatic Solenoid Valve
Get PDFPneumatic solenoid valve has been widely used in the vehicle control systems for meeting the rapid-reaction demand triggered by the dynamic conditions encountered during the driving course of vehicle. For ensuring the safety of human being, the reliable and effective solenoid valve is in great demand to shorten the reaction time and thus becomes the topic of this research. This numerical study chooses a commercial 3/2-way solenoid valve as the reference valve for analysing its performance. At first, CFD software Fluent is adopted to simulate the flow field associated with the valve configuration. Then, the comprehensive flow visualization is implemented to identify the locations of adverse flow patterns. Accordingly, it is found that a high-pressure region exists in the zone between the nozzle exit and the top of iron core. Thereafter, the nozzle diameter and the distance between nozzle and spool are identified as the important design parameters for improving the pressure response characteristics of valve. In conclusion, this work establishes a rigorous and systematic CFD scheme to evaluate the performance of pneumatic solenoid valve
Feasibility Study of a Reconfigurable Fiber-Wireless Testbed Using Universal Software Radio Peripheral
Get PDFFiber-wireless (FiWi) network is still improved ongoingly and there are a number of testbeds for the FiWi network available nowadays. However, most of them are hardware-based, making them not easy to reconfigure to perform architecture or protocol studies. This paper first proposes a reconfigurable FiWi testbed using software-defined radio, particularly universal software radio peripheral (USRP) with LabVIEW as the simulation platform. To evaluate the testbed, wireless range and power output were tested to optimize the best output for the USRP. With the range of 100 m, it was found that the best output power is 30 dB. Then, the study evaluated the performance of the upstream FiWi testbed transmission in terms of throughput, transmission time, and jitter. To test the testbed reconfigurability, the testbed architecture and transmission type were altered, and the performance was scrutinised. The experimental results indicate that USRP is suitable for a reconfigurable FiWi testbed
Applicability of Various Load Test Interpretation Criteria in Measuring Driven Precast Concrete Pile Uplift Capacity
Get PDFThis paper presents a comprehensive analysis of load test interpretation criteria to determine their suitability to driven precast concrete (PC) pile uplift capacity. A database was developed containing static pile load tests and utilized for the evaluation. The piles were round and square cross-sections under drained and undrained loading. To explore and compare their behavior, the stored data were categorized into four groups. In general, the trends of every criterion for the four groups were notably the same. In both drained and undrained loading, slightly larger interpreted capacities were demonstrated by square piles than by round piles. Moreover, round piles demonstrated more ductile load-displacement response than square piles especially in undrained loading. Statistical analyses presented that smaller values of displacements exhibited higher coefficient of variation. The drained and undrained tests were compared and results showed less variability in drained than undrained loading and capacity ratios (Qx/QCHIN) in drained loading were slightly higher than in undrained loading. The interrelationship and applicability of these criteria as well as the design recommendations in terms of normalized capacity and displacement were given based on the analyses