Modelling and Simulation in Engineering The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Some Aspects of Structural Modeling of Damage Accumulation and Fracture Processes in Metal Structures at Low Temperature Wed, 27 Jul 2016 11:23:44 +0000 The problem of brittle fracture of structures at low temperature conditions connected to damage accumulation and ductile-brittle transition in metals. The data for locomotive tire contact impact fatigue and spalling are presented. The results of experimental testing showed the impact toughness drop at low temperature. The internal friction method was applied to revealing of the mechanism of dislocation microstructure changes during the low temperature ductile-brittle transition. It has been shown for the first time that the transition is not connected to interatomic interactions but stipulated by thermofluctuation on nucleus such as microcracks and by their further growth and coalescence. From now on, the proposed mechanism would be used for theoretical and numerical modeling of damage accumulation and fracture in materials. Valeriy Lepov, Albert Grigoriev, Valentina Achikasova, and Kyunna Lepova Copyright © 2016 Valeriy Lepov et al. All rights reserved. Comparison of Parametric and Nonparametric Methods for Analyzing the Bias of a Numerical Model Mon, 30 May 2016 07:19:00 +0000 Numerical models are presently applied in many fields for simulation and prediction, operation, or research. The output from these models normally has both systematic and random errors. The study compared January 2015 temperature data for Uganda as simulated using the Weather Research and Forecast model with actual observed station temperature data to analyze the bias using parametric (the root mean square error (RMSE), the mean absolute error (MAE), mean error (ME), skewness, and the bias easy estimate (BES)) and nonparametric (the sign test, STM) methods. The RMSE normally overestimates the error compared to MAE. The RMSE and MAE are not sensitive to direction of bias. The ME gives both direction and magnitude of bias but can be distorted by extreme values while the BES is insensitive to extreme values. The STM is robust for giving the direction of bias; it is not sensitive to extreme values but it does not give the magnitude of bias. The graphical tools (such as time series and cumulative curves) show the performance of the model with time. It is recommended to integrate parametric and nonparametric methods along with graphical methods for a comprehensive analysis of bias of a numerical model. Isaac Mugume, Charles Basalirwa, Daniel Waiswa, Joachim Reuder, Michel d. S. Mesquita, Sulin Tao, and Triphonia J. Ngailo Copyright © 2016 Isaac Mugume et al. All rights reserved. Analysis of Muscle Activity Utilizing Bench Presses in the AnyBody Simulation Modelling System Wed, 11 May 2016 10:06:55 +0000 Using the AnyBody human modeling system with identical weights and varying grip distance (40.0 cm, 50.0 cm, and 60.0 cm), the stress distribution for the pectoralis and the muscle of upper extremity during a bench press was simulated, and the surface myoelectricity (EMG) method was validated. Methods. The physical parameters driving the model of the human body were selected as weights of 35.0% (25.0 kg) and grip distances. Conclusion. The validation of AnyBody software was proved as a high validity by using EMG test of four muscles’ activity compared to AnyBody software. During a bench press, the pectoralis major is the main muscle, the pectoralis major discharge increases with the height of barbell increases, and the pectoralis major discharge decreases as the short grip width increases. When the grip width equals the shoulder width, the value of pectoralis minor is lowest; when the grip width is smaller or larger than the shoulder width, the value is larger. As the short grip distance increases, the discharge of posterior deltoid muscle and triceps surface myoelectricity increases; thus, as the short grip distance increases, the deltoid muscle and triceps assist the pectoralis major during a bench press. Zhongqiu Ji, Huihui Wang, Guiping Jiang, and Lin Li Copyright © 2016 Zhongqiu Ji et al. All rights reserved. Development of Constitutive Model for Precast Prestressed Concrete Segmental Columns Sun, 27 Mar 2016 07:11:55 +0000 The interest of using precast segmental columns in construction of concrete bridges has significantly increased in recent years. One research area of concrete bridges is the application of Precast Prestressed Concrete Segmental (PPCS) Column in any structural analysis software or FE program code. Modeling a PPCS column, which consists of various materials with interaction between them, is complicated and time-consuming. This research attempts to formulate the stiffness matrix of PPCS columns in order to form the constitutive model in linear form to evaluate the response of the columns. A two-dimensional finite element model is presented in the finite element package ANSYS. Parametric studies are conducted by finite element models to verify the constitutive models for the PPCS column with a different number of concrete segments. Comparison between the constitutive model and the FE program results indicates that the constitutive model is accurate enough to predict the deformation of the PPCS columns. M. Hafezolghorani Esfahani, F. Hejazi, R. Vaghei, E. Nikbakht, and D. C. J. Tze Copyright © 2016 M. Hafezolghorani Esfahani et al. All rights reserved. Prediction on Power Produced from Power Turbine as a Waste Heat Recovery Mechanism on Naturally Aspirated Spark Ignition Engine Using Artificial Neural Network Tue, 22 Mar 2016 11:47:36 +0000 The waste heat from exhaust gases represents a significant amount of thermal energy, which has conventionally been used for combined heating and power applications. This paper explores the performance of a naturally aspirated spark ignition engine equipped with waste heat recovery mechanism (WHRM) in a sedan car. The amount of heat energy from exhaust is presented and the experimental test results suggest that the concept is thermodynamically feasible and could significantly enhance the system performance depending on the load applied to the engine. However, the existence of WHRM affects the performance of engine by slightly reducing the power. The simulation method is created using an artificial neural network (ANN) which predicts the power produced from the WHRM. Safarudin Gazali Herawan, Abdul Hakim Rohhaizan, Ahmad Faris Ismail, Shamsul Anuar Shamsudin, Azma Putra, Mohd Tahir Musthafah, and Ardika Ridal Awang Copyright © 2016 Safarudin Gazali Herawan et al. All rights reserved. Development of the Object-Oriented Dynamic Simulation Models Using Visual C++ Freeware Wed, 16 Mar 2016 13:44:36 +0000 The paper mostly focuses on the methodological and programming aspects of developing a versatile desktop framework to provide the available basis for the high-performance simulation of dynamical models of different kinds and for diverse applications. So the paper gives some basic structure for creating a dynamical simulation model in C++ which is built on the Win32 platform with an interactive multiwindow interface and uses the lightweight Visual C++ Express as a free integrated development environment. The resultant simulation framework could be a more acceptable alternative to other solutions developed on the basis of commercial tools like Borland C++ or Visual C++ Professional, not to mention the domain specific languages and more specialized ready-made software such as Matlab, Simulink, and Modelica. This approach seems to be justified in the case of complex research object-oriented dynamical models having nonstandard structure, relationships, algorithms, and solvers, as it allows developing solutions of high flexibility. The essence of the model framework is shown using a case study of simulation of moving charged particles in the electrostatic field. The simulation model possesses the necessary visualization and control features such as an interactive input, real time graphical and text output, start, stop, and rate control. Alexander I. Kozynchenko and Sergey A. Kozynchenko Copyright © 2016 Alexander I. Kozynchenko and Sergey A. Kozynchenko. All rights reserved. An Adaptive Object Tracking Using Kalman Filter and Probability Product Kernel Wed, 16 Mar 2016 08:16:00 +0000 We present a new method for object tracking; we use an efficient local search scheme based on the Kalman filter and the probability product kernel (KFPPK) to find the image region with a histogram most similar to the histogram of the tracked target. Experimental results verify the effectiveness of this proposed system. Hamd Ait Abdelali, Fedwa Essannouni, Leila Essannouni, and Driss Aboutajdine Copyright © 2016 Hamd Ait Abdelali et al. All rights reserved. Numerical Simulations as Tool to Predict Chemical and Radiological Hazardous Diffusion in Case of Nonconventional Events Thu, 21 Jan 2016 13:09:45 +0000 CFD (Computational Fluid Dynamics) simulations are widely used nowadays to predict the behaviour of fluids in pure research and in industrial applications. This approach makes it possible to get quantitatively meaningful results, often in good agreement with the experimental ones. The aim of this paper is to show how CFD calculations can help to understand the time evolution of two possible CBRNe (Chemical-Biological-Radiological-Nuclear-explosive) events: (1) hazardous dust mobilization due to the interaction between a jet of air and a metallic powder in case of a LOVA (Loss Of Vacuum Accidents) that is one of the possible accidents that can occur in experimental nuclear fusion plants; (2) toxic gas release in atmosphere. The scenario analysed in the paper has consequences similar to those expected in case of a release of dangerous substances (chemical or radioactive) in enclosed or open environment during nonconventional events (like accidents or man-made or natural disasters). J.-F. Ciparisse, A. Malizia, L. A. Poggi, O. Cenciarelli, M. Gelfusa, M. C. Carestia, D. Di Giovanni, S. Mancinelli, L. Palombi, C. Bellecci, and P. Gaudio Copyright © 2016 J.-F. Ciparisse et al. All rights reserved. Thermoelectric Modeling and Online SOC Estimation of Li-Ion Battery for Plug-In Hybrid Electric Vehicles Wed, 06 Jan 2016 11:12:33 +0000 The increasing oil price, energy demand, and environmental concern are leading to a global switch towards Plug-In Hybrid Electric Vehicles (PHEVs). In a PHEV, Li-ion battery is considered as the primary propelling source. Therefore, an accurate battery model is required to predict the characteristic and dynamic behavior of a battery. This paper presents a highly effective thermoelectric model of Li-ion battery developed in Simulink. An algorithm is proposed for estimation of state of charge (SOC) and open circuit voltage (OCV) adaptively to notify the exact SOC level for better utilization of battery power and optimal vehicle performance. Thermal behavior of Li-ion battery is investigated for wide temperature range and its effect on resistance, capacity, and OCV is recorded. The minimum SOC level to which battery can get depleted is calculated using gradient method. The proposed simulation results are analyzed with those of earlier models and found to be better. Aishwarya Panday, Hari Om Bansal, and Pramod Srinivasan Copyright © 2016 Aishwarya Panday et al. All rights reserved. A Comparative Study of Multiple Object Detection Using Haar-Like Feature Selection and Local Binary Patterns in Several Platforms Thu, 31 Dec 2015 11:32:38 +0000 Object detection has been attracting much interest due to the wide spectrum of applications that use it. It has been driven by an increasing processing power available in software and hardware platforms. In this work we present a developed application for multiple objects detection based on OpenCV libraries. The complexity-related aspects that were considered in the object detection using cascade classifier are described. Furthermore, we discuss the profiling and porting of the application into an embedded platform and compare the results with those obtained on traditional platforms. The proposed application deals with real-time systems implementation and the results give a metric able to select where the cases of object detection applications may be more complex and where it may be simpler. Souhail Guennouni, Ali Ahaitouf, and Anass Mansouri Copyright © 2015 Souhail Guennouni et al. All rights reserved. Optimized Sizing, Selection, and Economic Analysis of Battery Energy Storage for Grid-Connected Wind-PV Hybrid System Thu, 24 Dec 2015 09:45:43 +0000 Energy storages are emerging as a predominant sector for renewable energy applications. This paper focuses on a feasibility study to integrate battery energy storage with a hybrid wind-solar grid-connected power system to effectively dispatch wind power by incorporating peak shaving and ramp rate limiting. The sizing methodology is optimized using bat optimization algorithm to minimize the cost of investment and losses incurred by the system in form of load shedding and wind curtailment. The integrated system is then tested with an efficient battery management strategy which prevents overcharging/discharging of the battery. In the study, five major types of battery systems are considered and analyzed. They are evaluated and compared based on technoeconomic and environmental metrics as per Indian power market scenario. Technoeconomic analysis of the battery is validated by simulations, on a proposed wind-photovoltaic system in a wind site in Southern India. Environmental analysis is performed by evaluating the avoided cost of emissions. Hina Fathima and K. Palanisamy Copyright © 2015 Hina Fathima and K. Palanisamy. All rights reserved. Effect of Coastal Waves on Hydrodynamics in One-Inlet Coastal Nador Lagoon, Morocco Thu, 17 Dec 2015 07:09:00 +0000 Nador lagoon is a coastal system connected to the sea through a narrow and shallow inlet; understanding its hydraulic performance is required for its design and operation. This paper investigates the hydrodynamic impacts of the whole lagoon due to tidal waves using a numerical approach. In this study we use a two-dimensional, depth-averaged hydrodynamic model based on so-called shallow water equations solved within triangular mesh by a developed efficient finite volume method. The method was calibrated and validated against observed data and applied to analyze and predict water levels, tidal currents, and wind effects within the lagoon. Two typical idealized scenarios were investigated: tide only and tide with wind forcing. The predicted sea surface elevations and current speeds have been presented during a typical tidal period and show correct physics in different scenarios. Jeyar Mohammed, Elmiloud Chaabelasri, and Najim Salhi Copyright © 2015 Jeyar Mohammed et al. All rights reserved. Uncertainty Analysis of Mixing Efficiency Variation in Passive Micromixers due to Geometric Tolerances Tue, 15 Dec 2015 12:52:08 +0000 The geometric layout is the key factor for enhancing the efficiency of the fluid mixing in passive micromixers. Therefore, by adjusting the geometric design and by controlling the geometric parameters, one can enhance the mixing process. However, through any fabrication process, the geometric parameters present slight, inherent variation from the designed values than might affect the performance of the micromixer. This paper proposes a numerical study on the influence of the unavoidable geometric tolerances on the mixing efficiency in passive micromixers. A probabilistic simulation model, based on the Monte Carlo method, is developed and implemented for this purpose. An uncertainty simulation model shows that significant deviations from the deterministic design can appear due to small variations in the geometric parameters values and demonstrates how a more realistic mixing performance can be estimated. Irina Stanciu Copyright © 2015 Irina Stanciu. All rights reserved. Steady-State Analysis and Comparison of Control Strategies for PMSM Mon, 14 Dec 2015 06:57:12 +0000 Permanent Magnet Synchronous Motor (PMSM) has been considered as the best choice for numerous applications. To make PMSM a high performance drive, effective control system is required. Vector control is accepted widely due to its decoupling effect but it is not the only performance requirement. Additional control methods such as constant torque angle control (CTAC), optimum torque per ampere control (OTPAC), unity power factor control (UPFC), constant mutual flux linkages control (CMFLC), and angle control of air gap flux and current phasor (ACAGF) can also be implemented. This paper therefore presents some important control strategies for PMSM along with merits and limitations which provide a wide variety of control choices in many applications. The performance characteristics for each strategy under steady state are modelled and simulated in MATLAB environment. Based on the simulation results, a conclusion is drawn that OTPAC is superior in normalized torque per unit normalized stator current () ratio whereas UPFC yields very low ratio. In addition, performances of these control strategies are compared, which is a key to select optimum strategy depending on requirements. Based on the comparative study, it can be concluded that CMFLC is superior to CTAC, ACAGF, OTPAC, and UPFC. Hence, it can be a good control strategy to consider. Jyoti Agrawal and Sanjay Bodkhe Copyright © 2015 Jyoti Agrawal and Sanjay Bodkhe. All rights reserved. A Novel Geometric Modification to the Newton-Secant Method to Achieve Convergence of Order and Its Dynamics Wed, 09 Dec 2015 08:10:37 +0000 A geometric modification to the Newton-Secant method to obtain the root of a nonlinear equation is described and analyzed. With the same number of evaluations, the modified method converges faster than Newton’s method and the convergence order of the new method is . The numerical examples and the dynamical analysis show that the new method is robust and converges to the root in many cases where Newton’s method and other recently published methods fail. Gustavo Fernández-Torres Copyright © 2015 Gustavo Fernández-Torres. All rights reserved. A New Approach to Improve Accuracy of Grey Model GMC in Time Series Prediction Mon, 07 Dec 2015 12:47:23 +0000 This paper presents a modified grey model GMC for use in systems that involve one dependent system behavior and relative factors. The proposed model was developed from the conventional GMC model in order to improve its prediction accuracy by modifying the formula for calculating the background value, the system of parameter estimation, and the model prediction equation. The modified GMC model was verified by two cases: the study of forecasting CO2 emission in Thailand and forecasting electricity consumption in Thailand. The results demonstrated that the modified GMC model was able to achieve higher fitting and prediction accuracy compared with the conventional GMC and D-GMC models. Sompop Moonchai and Wanwisa Rakpuang Copyright © 2015 Sompop Moonchai and Wanwisa Rakpuang. All rights reserved. A Segmental Approach with SWT Technique for Denoising the EOG Signal Tue, 10 Nov 2015 14:03:47 +0000 The Electrooculogram (EOG) signal is often contaminated with artifacts and power-line while recording. It is very much essential to denoise the EOG signal for quality diagnosis. The present study deals with denoising of noisy EOG signals using Stationary Wavelet Transformation (SWT) technique by two different approaches, namely, increasing segments of the EOG signal and different equal segments of the EOG signal. For performing the segmental denoising analysis, an EOG signal is simulated and added with controlled noise powers of 5 dB, 10 dB, 15 dB, 20 dB, and 25 dB so as to obtain five different noisy EOG signals. The results obtained after denoising them are extremely encouraging. Root Mean Square Error (RMSE) values between reference EOG signal and EOG signals with noise powers of 5 dB, 10 dB, and 15 dB are very less when compared with 20 dB and 25 dB noise powers. The findings suggest that the SWT technique can be used to denoise the noisy EOG signal with optimum noise powers ranging from 5 dB to 15 dB. This technique might be useful in quality diagnosis of various neurological or eye disorders. Naga Rajesh Copyright © 2015 Naga Rajesh. All rights reserved. Numerical Investigation on Vortex Shedding from a Hydrofoil with a Beveled Trailing Edge Tue, 01 Sep 2015 09:53:18 +0000 To better understand the vortex shedding mechanism and to assess the capability of our numerical methodology, we conducted numerical investigations of vortex shedding from truncated and oblique trailing edges of a modified NACA 0009 hydrofoil. The hybrid particle-mesh method and the vorticity-based subgrid scale model were employed to simulate these turbulent wake flows. The hybrid particle-mesh method combines the vortex-in-cell and the penalization methods. We have implemented numerical schemes to more efficiently use available computational resources. In this study, we numerically investigated vortex shedding from various beveled trailing edges at a Reynolds number of 106. We then compared the numerical results with the experimental data, which show good agreement. We also conducted numerical simulations of wakes behind the hydrofoil at rest in periodically varying flows. Results reveal that vortex shedding is affected by the periodicity of a free-stream flow, as well as the trailing-edge shape. Seung-Jae Lee, Jun-Hyeok Lee, and Jung-Chun Suh Copyright © 2015 Seung-Jae Lee et al. All rights reserved. Continuous Finite Element Methods of Molecular Dynamics Simulations Thu, 13 Aug 2015 13:54:26 +0000 Molecular dynamics simulations are necessary to perform very long integration times. In this paper, we discuss continuous finite element methods for molecular dynamics simulation problems. Our numerical results about diatomic molecular system and triatomic molecules show that linear finite element and quadratic finite element methods can better preserve the motion characteristics of molecular dynamics, that is, properties of energy conservation and long-term stability. So finite element method is also a reliable method to simulate long-time classical trajectory of molecular systems. Qiong Tang, Luohua Liu, and Yujun Zheng Copyright © 2015 Qiong Tang et al. All rights reserved. Consistent Weighted Average Flux of Well-Balanced TVD-RK Discontinuous Galerkin Method for Shallow Water Flows Tue, 07 Jul 2015 10:28:51 +0000 A well-balanced scheme with total variation diminishing Runge-Kutta discontinuous Galerkin (TVD-RK DG) method for solving shallow water equations is presented. Generally, the flux function at cell interface in the TVD-RK DG scheme is approximated by using the Harten-Lax-van Leer (HLL) method. Here, we apply the weighted average flux (WAF) which is higher order approximation instead of using the HLL in the TVD-RK DG method. The consistency property is shown. The modified well-balanced technique for flux gradient and source terms under the WAF approximations is developed. The accuracy of numerical solutions is demonstrated by simulating dam-break flows with the flat bottom. The steady solutions with shock can be captured correctly without spurious oscillations near the shock front. This presents the other flux approximations in the TVD-RK DG method for shallow water simulations. Thida Pongsanguansin, Montri Maleewong, and Khamron Mekchay Copyright © 2015 Thida Pongsanguansin et al. All rights reserved. Characterization and Modelling of LeBlanc Hydrodynamic Stabilizer: A Novel Approach for Steady and Transient State Models Thu, 11 Jun 2015 08:20:40 +0000 As result of increase of customers’ demands, products become more complexes and dynamics control increased its role into product development. As example, clothing washing machines use LeBlanc balancers in order to reduce vibration issues. Nevertheless, the behaviour of such apparatus is still hard to describe and the numerical simulation of this sort of vibration control is based on ball rings. The main goal of this work is to define and characterize a numerical model that describes the hydrodynamics balance ring in the transient state in addition to steady state models. As consequence, the behaviour of balance ring was identified in a computational fluid dynamics tool and an equation that describes restoration forces, unbalance, force phase, and eccentricity was found. Marlon Wesley Machado Cunico Copyright © 2015 Marlon Wesley Machado Cunico. All rights reserved. Advanced Communication Models and Services for Smart World Mon, 27 Apr 2015 13:04:21 +0000 James J. Park, Ning Zhang, Neil Y. Yen, and Muhammad K. Khan Copyright © 2015 James J. Park et al. All rights reserved. Getting Business Insights through Clustering Online Behaviors Thu, 23 Apr 2015 15:37:28 +0000 This study aimed to explore the online users’ behaviors. Since the Internet was introduced to the market, the various and frequent online activities have increased, and it becomes more important for the businesses to understand the online users. Therefore this study analyzed the online users’ behaviors and segmented the users by using -means clustering method using actual clickstream data. There were four different research questions and, thus, four different sets of segmentations. It was found that many people find much of entertaining from online using SNS, games, and so on. In addition, some people only have access to a few specific websites. Some use the online service regularly every day while others use it in a very irregular pattern. People were divided into two groups, weekday group and weekend group. People are likely to be using the Internet either on weekdays or at weekend. Teenagers and people in their 50s are more likely to use it during weekend. In addition, teenagers also show different time zone (e.g., overnight) to use the Internet from other age groups. These results can shed light on understanding what consumers do online and what they are interested in currently and on decision making in marketing strategy. Jounghae Bang, Yoonho Cho, and Min Sun Kim Copyright © 2015 Jounghae Bang et al. All rights reserved. Design of Mobile Gateway for Implementation of Smart Work System Thu, 23 Apr 2015 12:31:33 +0000 In the development of new technologies based on mobile system, there is a growing interest as a fundamental technology. In particular, in order to realize a mobile office and mobile phones, conferencing remote document is a technique that can realize smart network services solutions with enhanced real-time communication, real-time information sharing, and collaboration. Therefore, in this paper, the design meets the diverse needs of customers and the smart work platform mobile-based fast and conveniently it is trying to develop. For this reason, I have developed a mobile gateway that is based on the communication server construction OPEN API development, management of mobile ID, protocol design, and design of SSL/TLS security tunnel. Also, we developed a smart work platform that you apply this, you are trying to provide information systems environment of mobile company. Sang-Young Oh and Bong-Hyun Kim Copyright © 2015 Sang-Young Oh and Bong-Hyun Kim. All rights reserved. An Intelligent Web Digital Image Metadata Service Platform for Social Curation Commerce Environment Thu, 23 Apr 2015 12:26:14 +0000 Information management includes multimedia data management, knowledge management, collaboration, and agents, all of which are supporting technologies for XML. XML technologies have an impact on multimedia databases as well as collaborative technologies and knowledge management. That is, e-commerce documents are encoded in XML and are gaining much popularity for business-to-business or business-to-consumer transactions. Recently, the internet sites, such as e-commerce sites and shopping mall sites, deal with a lot of image and multimedia information. This paper proposes an intelligent web digital image information retrieval platform, which adopts XML technology for social curation commerce environment. To support object-based content retrieval on product catalog images containing multiple objects, we describe multilevel metadata structures representing the local features, global features, and semantics of image data. To enable semantic-based and content-based retrieval on such image data, we design an XML-Schema for the proposed metadata. We also describe how to automatically transform the retrieval results into the forms suitable for the various user environments, such as web browser or mobile device, using XSLT. The proposed scheme can be utilized to enable efficient e-catalog metadata sharing between systems, and it will contribute to the improvement of the retrieval correctness and the user’s satisfaction on semantic-based web digital image information retrieval. Seong-Yong Hong and Sung-Joon Lee Copyright © 2015 Seong-Yong Hong and Sung-Joon Lee. All rights reserved. Computational Analysis to Factor Wind into the Design of an Architectural Environment Tue, 14 Apr 2015 08:37:39 +0000 The effect of wind distribution on the architectural domain of the Bahrain Trade Centre was numerically analysed using computational fluid dynamics (CFD). Using the numerical data, the power generation potential of the building-integrated wind turbines was determined in response to the prevailing wind direction. The three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations along with the momentum and continuity equations were solved for obtaining the velocity and pressure field. Simulating a reference wind speed of 6 m/s, the findings from the study quantified an estimate power generation of 6.4 kW indicating a capacity factor of 2.9% for the benchmark model. At the windward side of the building, it was observed that the layers of turbulence intensified in inverse proportion to the height of the building with an average value of 0.45 J/kg. The air velocity was found to gradually increase in direct proportion to the elevation with the turbine located at higher altitude receiving maximum exposure to incoming wind. This work highlighted the potential of using advanced computational fluid dynamics in order to factor wind into the design of any architectural environment. Hassam Nasarullah Chaudhry, John Kaiser Calautit, and Ben Richard Hughes Copyright © 2015 Hassam Nasarullah Chaudhry et al. All rights reserved. Study on Hot Deformation Behavior of 7085 Aluminum Alloy during Backward Extrusion Process Sun, 29 Mar 2015 11:39:04 +0000 Compression test was carried out and the true stress-strain curves were obtained from the hot compression of 7085 alloy. A numerical simulation on the deformation behavior of 7085 aluminum alloy during the backward extrusion was also performed by finite element method. The results show that dynamic recrystallization occurs in the hot compression of 7085 alloy and the peak stress reaches higher values as the strain rate increases and deformation temperature decreases. The backward extrusion processes include contact deformation, initial deformation, and steady deformation. Severe plastic deformation of shear and compression occurs when the metal flowed into the channel between fillet of punch and wall of die so that the grain size can be refined by backward extrusion. The deformation in the region of top of wall is too small to meet the mechanical properties of requirements and the metal usually needs to be trimmed. The experiments with the same parameters as simulation had been carried out and the experimental cup after extrusion has better quality. R. B. Mei, Y. X. Du, L. Bao, X. Y. Zhang, B. Zhang, and Z. J. Zhou Copyright © 2015 R. B. Mei et al. All rights reserved. Analysis on Cooling Effect of Crushed-Rocks Embankment of Qinghai-Tibet High-Grade Road Thu, 12 Mar 2015 08:23:07 +0000 In order to study the cooling effect of the crushed-rocks embankment, the permeability and the inertial resistance coefficient were measured by the wind tunnel test of spheres with a diameter of 20 cm, and then the stabilities of the closed crushed-rocks embankment with the wide pavement, the closed crushed-rocks embankment with the narrow pavement, and the duct-ventilated and closed crushed-rocks embankment were calculated. In the next 50 years, assuming that the temperature in Qinghai-Tibet plateau will rise by 2.6°C condition, the cooling effects of these three special high-grade embankment structures were studied. The test results and the numerical calculation results show that the relationship between pressure gradient and seepage velocity in the spheres layer diverges completely from Darcy’s law, and it shows a nice quadratic nonlinear relationship. Stabilities of those two closed crushed-rock embankments without the duct-ventilated structure could be destroyed because of the high permafrost temperature under embankments. The duct-ventilated and closed crushed-rocks embankment can cool down the permafrost effectively and raise the permafrost table and ensure the long-term thermal stability of permafrost under road. Dongqing Li, Kun Zhang, Gangqiang Tong, Feng Ming, and Xing Huang Copyright © 2015 Dongqing Li et al. All rights reserved. Self-Organizing Construction Method of Offshore Structures by Cellular Automata Model Mon, 09 Mar 2015 06:58:15 +0000 We propose a new algorithm to build self-organizing and self-repairing marine structures on the ocean floor, where humans and remotely operated robots cannot operate. The proposed algorithm is based on the one-dimensional cellular automata model and uses simple transition rules to produce various complex patterns. This cellular automata model can produce various complex patterns like sea shells with simple transition rules. The model can simulate the marine structure construction process with distributed cooperation control instead of central control. Like living organism is constructed with module called cell, we assume that the self-organized structure consists of unified modules (structural units). The units pile up at the bottom of the sea and a structure with the appropriate shape eventually emerges. Using the attribute of emerging patterns in the one-dimensional cellular automata model, we construct specific structures based on the local interaction of transition rules without using complex algorithms. Furthermore, the model requires smaller communication data among the units because it only relies on communication between adjacent structural units. With the proposed algorithm, in the future, it will be possible to use self-assembling structural modules without complex built-in computers. Takeshi Ishida Copyright © 2015 Takeshi Ishida. All rights reserved. Effect of Bend Radius on Magnitude and Location of Erosion in S-Bend Thu, 01 Jan 2015 09:52:30 +0000 Solid particle erosion is a mechanical process that removes material by the impact of solid particles entrained in the flow. Erosion is a leading cause of failure of oil and gas pipelines and fittings in fluid handling industries. Different approaches have been used to control or minimize damage caused by erosion in particulated gas-solid or liquid-solid flows. S-bend geometry is widely used in different fluid handling equipment that may be susceptible to erosion damage. The results of a computational fluid dynamic (CFD) simulation of diluted gas-solid and liquid-solid flows in an S-bend are presented in this paper. In addition to particle impact velocity, the bend radius may have significant influence on the magnitude and the location of erosion. CFD analysis was performed at three different air velocities (15.24 m/s–45.72 m/s) and three different water velocities (0.1 m/s–10 m/s) with entrained solid particles. The particle sizes used in the analysis range between 50 and 300 microns. Maximum erosion was observed in water with 10 m/s, 250-micron particle size, and a ratio of 3.5. The location of maximum erosion was observed in water with 10 m/s, 300-micron particle size, and a ratio of 3.5. Comparison of CFD results with available literature data showed reasonable and good agreement. Quamrul H. Mazumder, Siwen Zhao, and Kawshik Ahmed Copyright © 2015 Quamrul H. Mazumder et al. All rights reserved.