Abstract: In Fluent, the 3-D RNG k–ε mathematical model is employed to compute water and air mixture pipe flow. The dissolved oxygen convectionaεnd diffusion model is established to simulate the concentration distribution of dissolved oxygen with user defined scalar method. Velocity, pressure and dissolved oxygen concentration are computed. Then, dissolved oxygen concentration and pressure are compared with the data of physical model, and they agree with each other approximately, showing it is valid and reliable to compute the mixture pipe flow and dissolved oxygen concentration with the model .Furthermore, under a specific condition, velocity, pressure and dissolved oxygen concentration of water and air mixture pipe flow are computed and their characteristics are analyzed.
Abstract: Based on the analysis of structural characteristic superiority, the process of combustion, flue gas flow and heat transfer in the upright magnesium reducing furnace, the three dimensional mathematical model is devoloped. And numerical simulation is performed further with the commercial software FLUENT. Finally, the flow and temperature field in furnace and temperature field in reducing pot have been obtained. The results indicate that the upright magnesium reducing furnace has perfect flue gas flow field and temperature field to meet the challenge of the magnesium reducing process; the major factors that affect the magnesium reducing reaction are the low thermal conductivity of slag and the high chemical reaction heat absorption.
Abstract: Aim of this paper is to present a numerical method for modeling of the so-called “equivalent box section fiber beam concrete element”. By comparing hysteresis curves of specimen of the concrete structure plotted with rebar beam with those plotted with the equivalent box section beam under a set of loading cases, the following conclusions are obtained: 1) The modeling technology of equivalent box section beam can overcome the difficulty which the rebar in beam can only be used in static calculation, and the fiber beam element can be applied to dynamic explicit analysis; 2) By comparing hysteresis curves which are plotted by the rebar beam with those obtained with model of equivalent box section beam, it is found that results are in good agreement for a specific typical loading case; 3) By comparing hysteresis curves of the equivalent box section beam with experimental data under given loading case, numerical results indicate that numerical results obtained with proposed modeling technology can fit the experiment phenomena very well.
Abstract: A mathematical model for predicting turbulence flows with effects of streamline curvature under orthogonal curvilinear coordinates is developed in this paper .The SIMPLEC solution procedure has been used for the transformed governing equations in the transformed domain. The flows near a groin in a straight open channel are employed to test the capability of the proposed turbulence model in capturing the effects of local curvature .The comparison between the computed results and experimental data shows a satisfactory agreement.
Abstract: The paper aims to develop an intelligent modeling system using Microsoft Excel spreadsheet interface through mathematical language, mathematical reasoning and algorithms flow chart technique for manufacturing system optimization without human involvement. The paper begins to search for a mathematical theorem which is arithmetic series to represent a dynamic manufacturing system in a production floor using production time variable through numerical analysis and is validated using software simulation. The mathematical theorem is modeled with Industrial Engineering (IE) variables into spreadsheet to perform intelligent decision making. The model sets inventory target variable to be achieved with automated computation through the data input from users. Manual analysis from human can be transposed to mathematical language in order automate the system intelligently. The building of intelligent modeling system into spreadsheet using mathematical language sets a new platform for researchers to promote the next generation of modeling technique in the manufacturing field.
Abstract: Wire electric discharge machining (WEDM) process is considered to be one of the most suitable processes for machining metal matrix composite (MMC) materials. Lot of research work has been done on WEDM process, but very few investigations have been done on WEDM of MMCs. The purpose of this research work is to develop the artificial neural network (ANN) model to predict the material removal rate (MRR) during WEDM of SiCp/6061 Al MMC. In this work four input parameters namely servo voltage, pulse-on time, pulse-off time and wire feed rate were used to develop the ANN model. The output parameter of the model was MRR. A Box-Behnken design (BBD) approach of response surface methodology (RSM) was used to generate the input output database required for the development of ANN model. Training of the neural network models were performed on 29 experimental data points. The predicted values obtained from ANN model show that model can predict MRR with reasonable accuracy. The good agreement is obtained between the ANN predicted values and experimental values. In the present case, the value of correlation coefficient (R) equal to 0.9968, is closer to unity for ANN model of MRR. This clearly indicates that prediction accuracy is higher for ANN model.
Abstract: Precise and secure handling of flexible or irregularly shaped objects by robotic hands has become a challenge. Robot hands used in medical robotics and rehabilitation robotics need to be anthropomorphic to do the desired tasks. Although it is possible to develop robotic hands which can be very closely mapped to human hands, it is sometimes poses several problems due to control, manufacturing and economic reasons. The present work aims at designing and developing a robotic hand with five fingers for manipulation of objects. The kinematic modeling and its analysis, as a part of the development process is presented in this paper. The simulation results of the hand shows that the conceptualized design is yielding the desired result and works very efficiently.
Abstract: In this study a Finite Element Analysis for cantilever plate structure excited by proof mass is presented. To investigate the influence of different geometry parameters like thickness, length and width on the maximum deflection and resonance frequency. Configuration of piezoelectric actuators attached to the plate structure in order to identify the optimal configuration of the actuators for selective excitation of the mode shapes of the cantilever plate structure. The Finite Element Modeling based on ANSYS12.0 package using modal analysis and harmonic analysis is used in this study for cantilever plate structure excited by patch type of piezoelectric plates of PZT-5H4E of different geometrical parameters like thickness, length & width on the cantilever beam. To study the maximum deflection , the readings are taken by varying different geometry parameters . With this different geometrical parameters first modal analysis is done to know the different modes shapes and their natural frequencies and the frequency of particular mode shape at which the deflection is maximum. Then in the second stapes Harmonic Analysis is carried out near same frequency and the deflection amplitude is found out. Thus simulation of a cantilever beam is done by varying different thickness of piezoelectric plates and the substrate material. The same simulation is carried for different lengths’ & width. Finally the results are combine presented on graph , which clearly shows the effect of variation of geometry parameters on the beam deflections and accordingly change in natural frequency.
Abstract: In this study, the appropriate input parameters for achieving minimum surface roughness and high material removal rate are selected for wire electrical discharge machining of cold-work steel 2601. Mathematical modeling acquired by experimental result analysis is used to find the relation between input parameters including electrical current, gap voltage, open-circuit voltage and pulse-off time and output parameters. Subsequently, with exploitation of variance analysis, importance and effective percentages of each parameter are studied. The combination of optimum machining parameters is acquired using the analysis of ratios of signal-to-noise. Finally, according to multiple-objective optimization, outputs acquired from Non-dominated Sorting Genetic Algorithm led in achieving appropriate models. The optimization results showed suggested method has a high performance in problem solving.
Abstract: Car cabin acoustical comfort is one of the factors which attract the buyer prospective buyer on purchasing a new vehicle. Basically the amount of discomfort depends to magnitude, frequency, direction and also the duration of exposed vibration in the cabin. The comfort of the driving influences driving performance. Generally the vibration is caused by two main sources: engine transmission and interaction between tyre and road surface. In this study the effects of vibration to noise in passenger car cabin were investigated. Vehicle acoustical comfort index (VACI) was used to evaluate the noise annoyance level and vibration dose value (VDV) was used to evaluate the vibration level. By referring to the noise and vibration trend to engine speeds, an optimization model was built to find the optimal VDV value against the engine speed in order to obtain required maximum noise (VACI) in the passenger car cabin. Thus, a VACI-VDV reference table formed to assist automotive researchers to reduce the vibration and at the same time to reduce noise annoyance level in passenger car cabin.