bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysing a Design and Technology Development Framework Through the Implementation of a Prototype Composite Vehicle Suspension System
Authors: Hurter W. S. , Janse van Rensburg N. , Madyira D. M.
Published: February 2017

A uniquely configured suspension system, manufactured primarily of lightweight composite materials, is required for the University of Johannesburg’s solar powered race vehicle. For this design to reach successful completion, an assessment framework is introduced that would scrutinise and analyse different stages of the development. The focus of this paper is on the design and development of a prototype composite vehicle suspension system and assessing the framework implemented to control the research and development process of composite components.
Numerical Investigation of Effects of Non-Uniform Tip Clearance on Flow Field Inside a Turbine Cascade
Authors: Ma Hongwei , Tian Yangtao
Published: February 2017

In the unshrouded axial turbine, the tip clearances can result in the loss of turbine efficiency and the penalty of turbine performance. Therefore, investigating the blade tip geometry of improving the turbine performance has a great significance. This paper is to study the effects of non-uniform tip clearance on the flow field in a turbine cascade. The numerical works are performed at the incidence angle of 0 degree and the exit Reynolds number of 1.7 × 105 based on the blade chord. In the investigations, the flat tip (Basic) geometry was employed as a benchmark, and three different tip geometries, including the pressure side squealer (PSQ), suction side squealer (SSQ) and grooved tip (Grooved), were studied. The tip clearances are all specified as 1.18% of the chord. The squealer height is set to 2.94% of the chord. The endwall static pressure, tip leakage loss, flow capacity and the development of tip leakage vortex are discussed. And the numerical results show that the grooved tip which can obtain the least total pressure loss, is helpful to smooth the pressure change from pressure side to suction side and suppress the intensity of tip leakage vortex. The tip clearance flow in the pre semi-passage is mainly involved in the passage vortex, and in the post semi-passage it is added to the tip leakage vortex. Compared with the Basic, PSQ and SSQ tips, the Grooved tip contributes to reducing the tip leakage flow and the tip leakage loss. And the leakage flow can be strengthened in the middle passage for the PSQ. The difference between the area averaged streamwise coefficient and mass averaged loss is almost opposite for the SSQ and Grooved tip, which is uncertain the performance of the turbine cascade with the SSQ and Grooved tip is better than the Basic tip.
Improved Surface Roughness Evaluation of Ground Components Using Illumination Compensated Image: A Machine Vision Approach
Authors: G. John Jibin , Narayanaperumal Arunachalam
Published: February 2017

One of the crucial elements of image based inspection system development is the lighting conditions. It directly defines the quality of the image which in turn affects the accuracy and robustness of an inspection procedure using machine vision system. The common image characteristics change with variation in lighting leading to large image differences. In recent years, evaluation of surface roughness of a work piece by machine vision has received a great deal of attention. However, practical surface roughness instruments based on machine vision are still difficult to develop for application specific online assessment in particular. This is due to the fact that the images taken from the machined surfaces are affected by illumination, reflectivity and ambience during the image acquisition process. This lighting inhomogeneity is considered to be a disturbing signal component, which should be suppressed to achieve consistency in surface roughness quantification. In this paper, the illumination compensated images are used for surface roughness evaluation. The homomorphic filtering and Discrete Cosine Transform (DCT) based normalization techniques are utilized to remove the illumination inhomogeneity and the performance of these techniques were compared. The results clearly indicate that it is important to consider the lighting conditions when the machine vision approach is used to quantify the surface texture parameters.
Thermoeconomic Analysis of an Organic Rankine Cycle Coupled to an ICE-Based Cogeneration Plant
Authors: Badami Marco , Mangiantini Ilaria , Portoraro Armando , Verda Vittorio , Vigliani Elisa
Published: February 2017

This paper presents a mathematical model for the thermo-economic evaluation of an Organic Rankine Cycle (ORC), which recovers exhaust gases from an internal combustion engine (ICE) based cogeneration plant, currently in operation in Turin, Italy. The model is based on a complete set of experimental data of the plant, for both nominal and partial load operation conditions. The main components of the ORC plant have been modelled and a thermo-economic analysis has been carried out for each component. The aim of the paper is to perform a thermo-economic analysis of the system through the Theory of Exergetic Cost, in order to provide a complete diagnosis of the plant, by quantifying the performances of the whole system and its sub-systems, and by determining the monetary costs and the exergetic costs. The model can represent a useful decision-making tool for the optimal design of similar plants.
Experimental Investigation of a Spark Ignited Engine Using Magnetic Air Conditioner (MAC) for Improved Performance and Reduced Emissions
Authors: Hargude N. V. , Sawant S. M.
Published: February 2017

In 21st century, to cope up with exponential technological development, use of eco-friendly conventional energy system is a critical issue. Saving of energy is nothing but production of energy. Conventional fuel used in stationary power plant an IC engine is bulk in quantity, which will not be last longer and will exhaust very soon. Stationary power plants and Automobile propelled by I.C. engines have a problem of pollutant emission in environment which mainly depends on combustion process occurs in power plant and I.C. engines. Incomplete combustion of hydro-carbon fuel/s produce very large amount of harmful emission gases resulting into smog in cities & reduces performance of the system. These systems, equipped with Internal Combustion or External combustion produces large amount of exhaust gases CO, HC and NOx like monoxides etc. Since hazardous emissions which are harmful to human life and ecosystem resulting in many types of diseases of human especially in urban areas where automobile vehicle equipped with IC engine density is very high. These emissions have effect on result in environmental cycles also. In today’s globalised world, many attempts are made to reduce intensity of hazardous emissions of an IC engine through pre processing of fuels and post processing combustion exhaust gases in IC engine by many means like MPFI, PCV, EGR, catalytic converter, supercharger, turbocharger, etc. In order to handle, these issues, additional attempt is made. This attempt uses Air conditioner/Energizer for Pre-processing air and unit developed called as Magnetic air Conditioner (MAC).

A permanent magnet, magnetic air conditioner (MAC) is mounted in path of air lines. Mounting MAC in air line enhances quality of air and air molecules properties like it aligns and orientations, especially in an oxygen molecule. Better atomization of an oxygen molecule which further enters into combustion chambers of SI engine along with air. In a conventional four stroke spark Ignited engine, oxygen molecules reacts with hydro -carbon, which assist for complete combustion of hydro-carbon. Use of such Magnetic air conditioners improves performance of SI engine. The specific fuel consumption also decreases, resulting in to decrease in BSFC with increase in load. Use of MAC in engine also reduces emissions like CO, HC, ultimately resulting into reduction in smog in urban areas. The present article describes the mechanism of MAC, objectives and its effect on SI engine, such as enhanced performance parameter, various efficiencies like mechanical, brake thermal, volumetric saving in fuel, and reduced emission. One case study is presented in which ferrite magnets are used as MAC which improves performance and reduces emissions.
Using an Extendable Bumper With an Aid of Vehicle Dynamics Control System to Improve the Occupant Safety in Frontal Vehicle-to-Vehicle Collision Scenario
Authors: Elkady Mostafa , Elmarakbi Ahmed , MacIntyre John
Published: February 2017

This paper aims to improve vehicle crashworthiness using vehicle dynamics control systems (VDCS) integrated with an extendable front-end structure (extendable bumper). The work carried out in this paper includes developing and analyzing a new vehicle dynamics/crash mathematical model and a multi-body occupant mathematical model in case of vehicle-to-vehicle full frontal impact. The first model integrates a vehicle dynamics model with the vehicle’s front-end structure to define the vehicle body crash kinematic parameters. In this model, the anti-lock braking system (ABS) and the active suspension control system (ASC) are co-simulated, and its associated equations of motion are developed and solved numerically. The second model is used to capture the occupant kinematics during full frontal collision. The simulations show considerable improvements using VDCS with and without the extendable bumper (EB), which produces additional significant improvements for both vehicle body acceleration and intrusion.
The Influence of Laser Irradiation Parameters on Tribological Behaviour of Commercially Pure Titanium for Dental Prostheses
Authors: Shanmuga Sundaram Karibeeran , Kiliyappan Gurusami , Kumaran Selvadurai Senthil
Published: February 2017

Laser shock peening (LSP) is one of the innovative technique that produces a compressive residual stress on the surface of metallic materials, thereby significantly increasing its fatigue life in applications where failure is caused by surface-initiated cracks. The specimens were treated with laser shock waves with different processing parameters, and characterization studies were made on treated specimens. The purpose of the present study was to investigate the influence of Nd:YAG laser on commercially pure titanium (CP-Ti) used in prosthetic dental restorations. The treatment influenced change in microstructure, micro hardness, surface roughness, and wear resistance characteristics. Though CP-Ti is considered as an excellent material for dental applications due to its outstanding biocompatibility, it is not suitable when high mastication forces are applied. In the present study, pulsed Nd:YAG laser surface treatment technique was adopted to improve the wear resistance of CP-Ti. The wear test pin specimens of CP-Ti were investment cast with centrifugal titanium casting machine. The wear properties of specimens were evaluated after LSP on a “pin-on-disc” wear testing tribometer, as per ASTM G99-05 standards. The results of the wear experiment showed that the treated laser surface has higher wear resistance, micro hardness, and surface roughness compared to as-cast samples. The improvement of wear resistance may be attributed due to grain refinement imparted by LSP processes. The microstructure, wear surfaces, wear debris, and morphology of the specimen were analyzed by using optical electron microscope, scanning electron microscope, and X-ray diffraction (XRD). The data were compared using ANOVA and post-hoc Tukey tests. The characteristic change resulted in increase in wear resistance and decrease in wear rate. Hence, it is evident that the more reliable and removable partial denture metal frameworks for dental prostheses may find its applications.
Analytical and Experimental Studies of Flexoelectric Beam Control
Authors: Zhang Xufang , Li Huiyu , Tzou Hornsen
Published: February 2017

Flexoelectricity includes two effects: the direct flexoelectric effect and the converse flexoelectric effect, which can be respectively applied to flexoelectric sensors and actuators to monitor structural dynamic behaviors or to control structural vibrations. This study focuses on the converse flexoelectric effect and its application to dynamic control of cantilever beams analytically and experimentally. In the mathematical model, a conductive atomic force microscope (AFM) probe with an external voltage is used to generate an inhomogeneous electric field driving the flexoelectric beam. The electric field gradient leads to an actuation stress in the longitudinal direction due to the converse flexoelectric effect. The actuation stress results in a bending control moment to the flexoelectric beam since the stress in the thickness is inhomogeneous. In order to evaluate the actuation effect of the flexoelectric actuator, the flexoelectric induced tip displacement is evaluated when the mechanical force is assumed zero. With the induced control moment, vibration control of the cantilever beam is discussed and the control effect is evaluated. Flexoelectric control effects with different design parameters, such as AFM probe location, AFM probe radius and flexoelectric beam thickness, are evaluated. Analytical results show that the optimal AFM probe location for all beam modes is close to the fixed end. Besides, thinner AFM probe radius and thinner flexoelectric beam enhance the control effects. Laboratory experiments are also conducted with different probe locations to validate the analytical predictions. Experimental results show that the induced tip displacement decreases when the input location moves away from the fixed end, which is consistent with the analytical prediction. The studies provide design guidelines of flexoelectric actuations in engineering applications.
3D Computational Analysis of Thermal and Hydraulic Performance of Louvered Fin Heat Exchanger With Variable Louver Angle and Louver Pitch
Authors: Okbaz Abdulkerim , Pınarbaşı Ali , Olcay Ali Bahadır
Published: February 2017

In the present study, 3-D numerical simulations on heat and fluid flow characteristics of double-row multi-louvered fins heat exchanger are carried out. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles in the range of 20° ≤θ≤ 30°, louver pitches of Lp = 2,7mm, 3,5mm and 3,8mm and frontal velocities of Uin between 1.22 m/s and 3 m/s. The results are reported in terms of Colburn j-factor, Fanning friction factor f and area goodness factor j/f based on louver angle, louver pitch and Reynolds number. To understand local behavior of flow around louvered fins and heat exchanger tubes, flow visualization results of velocity vectors and stream-lines with temperature counters are presented. It is investigated that increasing louver angle enhances convective heat transfer while hydraulic performance decreases due to increased pressure drop. The flow noticeably behaves louver directed for all louver angles The flow can easily travel between different fins. This case study has been done to design and manufacture an industrial louver fin heat exchanger.
Dynamic and Predictive Optimization Concept for Energy Supply Systems in the Energy-Intensive Industry
Authors: Koller Martin , Hofmann René
Published: February 2017

Increasing flexibility for energy-intensive industry is gaining more and more importance due to the changing energy market towards volatile energy sources. Flexibility can be achieved by adapting the energy supply processes and integrating new components, e.g. energy storages. Another way to increase flexibility is to optimize the plant operation to exploit the full potential of the industrial plant. This paper presents a concept for optimal plant control for more flexible operation, using a two-stage optimization approach, combining a quadratic and a nonlinear optimization problem formulation. The optimization concept is demonstrated by means of a simple model plant. The input parameters are energy prices and production schedules respectively heat demands to be satisfied by the plant’s energy supply system. The output is the optimal control trajectory for the considered plant components. Four different scenarios, with varying plant configurations, are simulated and the results are discussed in terms of the optimization approach and the impact of different plant configurations.
Diagonal Piezoelectric Sensor on Cylindrical Shells Excited by Piezoelectric Actuator
Authors: Shen N. W. , Zhang X. F. , Li H.
Published: February 2017

A model of piezoelectric sensor based on cylindrical shell is designed in this paper. In this model, a rectangular piezoelectric patch is diagonally attached on the thin cylindrical shell as the sensing patch. To evaluate the output of sensing signal, the model is driven by piezoelectric actuator. Sensing and actuating mechanisms are formulated, and the governing equations are derived. To evaluate the contributions of strain components, the sensing signal is decomposed into six components. It is shown that the signal components vary with the orientation angles of sensing patches, so is the total sensing signal. Theoretical results show that shear strain contributes to sensing signal output when the sensing patch is diagonally attached. Then these results are experimentally validated. The transverse displacements and sensing voltages of sensing patch with three different orientations were measured, the sensitivity was calculated. All these analytical data can be used to optimize the piezoelectric sensor design.
Development of an Empirical Model to Predict Sulfuric Acid Condensate Formation in Air Handling System of Medium Speed Diesel Engines
Authors: Raina Pranav , Primus Roy J. , Jayakar Vijayaselvan , T. Harish Dayanand , Kalavara Aravind
Published: February 2017

One of the biggest challenges for engines used in Marine industry is to burn fuels of varied compositions, since the vessels often move from regions with highly regulated fuels to regions with no regulations, unlike their on-road and other stationary counterparts. This poses an enormous risk to the performance, reliability, durability and service life of engines that employ exhaust gas recirculation (EGR) as a prime technology to meet stringent emission regulations, laid out by various regulating bodies across the globe like the United States (U.S.) Environmental Protection Agency (EPA) and International Maritime Organization (IMO).

Operating on fuels with higher Sulfur content poses a risk of reduced engine component life, due to the formation of concentrated Sulfuric acid (H2SO4), which, if not handled carefully, would lead to higher rates of corrosion on engine parts. Hence, the ability to predict the potential for H2SO4 formation as well its quantity to be handled is essential.

This research paper focuses on the development of an empirical model to predict the amount of H2SO4 condensate that can be formed in the air handling system of medium speed diesel engines. The model utilizes a combination of fundamental physics, chemistry, thermodynamics and chemical kinetics. The H2SO4 prediction calculation employs basic measurable parameters from a running engine, such as engine speed, load, EGR flow rate, fuel flow rate, fuel Sulfur concentration to compute a molar balance of hydrocarbon fuel and combustion air quantities along the entire range of engine operation, providing the amount of H2SO4 condensate formed. This is done primarily at EGR cooler, where the recycled exhaust gas gets cooled primarily and the EGR mixer, where it gets cooled further after coming in contact with the charge air and are identified as critical locations.
Optimisation of Power Plant Operating on Waste Heat of Gas IC Engine Driven Power Generator
Authors: Read Matthew G. , Smith Ian K. , Stosic Nikola
Published: February 2017

This paper describes the results of computation analysis aimed at assessing the potential benefits of several thermodynamic cycles for the recovery of waste heat from gas IC engines. This is achieved by modelling the plant and expander processes which provides the general specification of the plant in terms of key design parameters. Simultaneously, the thermodynamic performance of each cycle is calculated in terms of flow rate, power and efficiency. Detailed component models allow a rigorous investigation of the design and performance of Organic Rankine Cycle and Wet steam Cycle systems for these applications where the energy from both the water jacket and exhaust gas can be utilised. A number of system configurations are considered including cycles with wet steam expansion and organic Rankine cycles with dry vapour expansion, and the benefits of a steam-ORC cascaded arrangement are investigated. Optimisation of the system configurations provides valuable insight into the performance and practical requirements of IC waste heat recovery systems.
Investigation of the Dynamic Characteristics of Bovine Tibia Using the Impulse Response Method
Authors: Choucair I. , Mustapha S. , Fakhreddine A. , Sayegh M. , Hamade R. F.
Published: February 2017

Seven bovine tibias were investigated in this work in a free-free boundary-condition setup and were excited with an impact hammer. Modal frequencies were extracted using the frequency response function of acceleration data captured from four different accelerometers distributed evenly along the bone span. Statistically significant correlations were found between the excited modes and the ratio of the tibia’s perimeter at mid-span to its length. Consequently, linear regression models were fitted to the data resulting in simple equations that relate modal frequencies of a tibia to these basic geometrical features. For the free-free set-up used in this study and consistent for all the bones tested, it was found that mode 2 is approximately double that of mode 1.
Analysis of Fracture Mechanism on Paper Tubes and Relationship Between Paperboard Property and Property of Paper Tubes
Authors: Suda Mitsunori , Kitamura Takanori , Zhang Zhiyuan , Hamada Hiroyuki
Published: February 2017

According to the report in May, 2015 by Japan Paper Recycling Promotion Center, quantity of paper and paperboard product in Japan decreases is about 18% from 2007 to 2014. Japanese quantity of waste paper in 2014 is 21750000ton, the rate of collected waste paper is 80.8%. Nevertheless Japanese consumption of waste paper is 17190000ton, the rate of utilizing waste paper is 63.9%. It means that quantity of collected waste paper become bigger than quantity of utilizing waste paper, a lot of waste-paper is exported to East Asia (especially China). Balance of waste paper demand and supply in Japan has already broken. It could be expected that waste paper will be collected more and more, but it is difficult to solve the problem that all domestic collected waste paper is used, in order to increasing phenomenon of helpful to recycle, energy saving, environmental protection movement. It is considered that the usage of paper tube need to be expanded which is produced by waste paper. Paper tube has been widely applied in many areas, such as packaging industry, film rolls, adhesive-tape industry, furniture decoration, temporary structures in building and so on. For example churches could be made from paper. The mechanical property of paper tube need to be investigated to get wide application.

At current study, the mechanical property of 8 kinds of paperboards for paper tubes fabrication were investigated included tension, compression and peeling properties combining with anisotropic property. These kinds of paperboards have different mechanical properties but same dimension. By this method, the effects of different properties including tension, compression and peeling on mechanical property of paper tubes could be evaluated. A series of paper tubes with different layers was fabricated and the lateral compression test was carried out and evaluated. The fracture form of paper tubes and fracture position on paper tubes were discussed together with paperboards properties. The cause of delamination behavior of laminated paper was analysis based on the detailed observation and finite element analysis. From fracture process, it was found that the main fracture of paper tube is delamination during lateral compression action which was considered peeling action has a big influence. According to this phenomenon, acoustic emission (AE) and observation of peeling paperboard were conducted.
Static Force Analysis of Wheel Bolt Under Multiple Working Conditions
Authors: Yi J. J. , Shan Y. C. , Liu X. D. , Wang J. G.
Published: February 2017

Vehicle wheel fastening bolts bear large load and load condition are very complex. Especially for commercial vehicles, it is common that loosening, broken and other failure situations occur on the wheel bolts during its running which has harmful effects on the safety of driving. However, at present, the parameters of wheel bolt like PCD, the number of bolts and so on are selected according to industry standards based on experience only. There are a few of literatures concerned with the calculation of the strength check of the wheel bolts, also there are still some gaps between existing related literatures and real situation. So it is necessary to carry out the specific stress analysis and make sure the selection is reasonable and also make sure that bolt strength meets the requirements when determining parameters of the bolts. In this paper, a specific force analysis method is carried out under six typical working conditions containing full load static condition, accelerating condition, braking condition, turning condition, rolling condition and impact condition. The force analysis method proposed in this paper is applied to a kind of commercial vehicle, which provides a theoretical basis for the determination of the parameters.
Experimental Investigation on Convective Heat Transfer Enhancement of Laminar Slot Jet Impingement in the Presence of Porous Medium
Authors: Chinige Sampath Kumar , Pattamatta Arvind
Published: February 2017

An experimental study using Liquid crystal thermography technique is conducted to study the convective heat transfer enhancement in jet impingement cooling in the presence of porous media. Aluminium porous sample of 10 PPI with permeability 2.48e−7 and porosity 0.95 is used in the present study. Results are presented for two different Reynolds number 400 and 700 with four different configurations of jet impingement (1) without porous foams (2) over porous heat sink (3) with porous obstacle case (4) through porous passage. Jet impingement with porous heat sink showed a deterioration in average Nusselt number by 10.5% and 18.1% for Reynolds number of 400 and 700 respectively when compared with jet impingement without porous heat sink configuration. The results show that for Reynolds number 400, jet impingement through porous passage augments average Nusselt number by 30.73% whereas obstacle configuration enhances the heat transfer by 25.6% over jet impingement without porous medium. Similarly for Reynolds number 700, the porous passage configuration shows average Nusselt number enhancement by 71.09% and porous obstacle by 33.4 % over jet impingement in the absence of porous media respectively.
Applicability of Heat Mirrors in Reducing Thermal Losses in Concentrating Solar Collectors
Authors: Mahendra Prashant , Khullar Vikrant , Mittal Madhup
Published: February 2017

Flux distribution around the parabolic trough receiver being typically non-uniform, only a certain portion of the receiver circumference receives the concentrated solar irradiance. However, radiative and convective losses occur across the entire receiver circumference. This paper attempts to introduce the idea employing transparent heat mirror to effectively reduce the heat loss area and thus improve the thermal efficiency of the solar collector. Transparent heat mirror essentially has high transmissivity in the solar irradiance wavelength band and high reflectivity in the mid-infrared region thus it allows the solar irradiance to pass through but reflects the infrared radiation back to the solar selective metal tube. Practically, this could be realized if certain portion of the conventional low iron glass envelope is coated with Sn-In2O3 so that its acts as a heat mirror.

In the present study, a parabolic receiver design employing the aforesaid concept has been proposed. Detailed heat transfer model has been formulated. The results of the model were compared with the experimental results of conventional concentrating parabolic trough solar collectors in the literature. It was observed that while maintaining the same external conditions (such as ambient/initial temperatures, wind speed, solar insolation, flow rate, concentration ratio etc.) the heat mirror-based parabolic trough concentrating solar collector has about 3–12% higher thermal efficiency as compared to the conventional parabolic solar collector. Furthermore, steady state heat transfer analysis reveals that depending on the solar flux distribution there is an optimum circumferential angle (θ = θoptimum, where θ is the heat mirror circumferential angle) up to which the glass envelope should be coated with Sn-In2O3. For angles higher than the optimum angle, the collector efficiency tends to decrease owing to increase in optical losses.
Experimental Study on Heat Transfer Capability of a Miniature Loop Heat Pipe
Authors: Zhou Guohui , Li Ji , Lv Lucang
Published: February 2017

In this paper, a miniature loop heat pipe (mLHP) with a flat evaporator is illustrated and investigated experimentally, with water as the working fluid. The mLHP can be applied for the mobile electronics cooling, such as tablet computers and laptop computers, with a 1.2 mm thick ultra-thin flat evaporator and a thickness of 1.0 mm for the vapor line, liquid line and condenser. A narrow sintered copper mesh in the liquid line and a part of the condenser as the secondary wick can promote the flow of the condensed working fluid back to the evaporator. The experimental results showed that the mLHP could start up successfully and operate stably at low heat load of 3 W in the horizontal orientation, and transport a high heat load of 12 W (the heat flux of 4 W/cm2) with the evaporator temperature below 100 °C in different test orientations by natural convection, showing good operational performance against gravity field. The minimum mLHP thermal resistance of 0.32 K/W was achieved at the input heat load of 12 W in the horizontal orientation.
Transient Heat Transfer Measurements for Planar and Circular Wall Jet Using Liquid Crystal Thermography
Authors: Godi Sangamesh C. , Pattamatta Arvind , Balaji C.
Published: February 2017

The objective of this study is to compare the fluid flow and the heat transfer characteristics between a 2-D planar and a 3-D circular wall jet along the stream wise direction. The experiments are performed at a Reynolds number of 5540 for non-dimensional streamwise distance ranging from 0 to 40. The hot wire anemometer is used to quantify the velocity distribution on the jet spread and the local maximum velocity decay along the stream wise direction. Liquid Crystal Thermography (LCT) technique is used to map the surface temperature and the semi-infinite approximation methodology is used for extracting the heat transfer coefficient. From the results it is observed that, the 2-D planar wall jet shows lesser distribution of RMS values in the near field and better heat transfer performance than that of the 3-D circular wall jet.
Characterization of Mechanical Properties of Date Palm Fronds Reinforced Composites: A Comparative Evaluation
Authors: Alzebdeh K. , Nassar M. , Al Rawahi H. , Al-Hinai N.
Published: February 2017

Due to many advantages of using natural resources, natural fibers have been used recently as a method of providing added strength and ductility to reinforced polymer composites. This is mainly due to their availability, renewability, low density, cost effectiveness as well as satisfactory mechanical properties. This paper presents fabrication and experimental characterization analysis of mechanical properties of a class of bio-composite in which polypropylene (PP) and low density polyethylene (LDPE) are reinforced with date palm frond fibers. Bio-composite sheets were fabricated with controlled processing parameters based on small factorial design in order to develop a statistical model for response using fractional design of experiment. In a Design of Experiment (DoE) procedure, we identify three different factors along with three different levels; fiber volume fraction (20, 40, and 60 vt. %), alkali treatment (10, 15, and 20 Wt. %), and treatment time (2, 4, and 6 h). In this study, NaOH alkali solution is used to modify the fiber properties and improve surface characteristics. The tensile and flexural strengths of specimens prepared according to ASTM standards were measured by direct physical testing. Also, the Response Surface Methodology (RSM) is adopted to analyze interactions among the input factors and their effect on overall mechanical properties of the fabricated composite. Results revealed that fiber length and percentage of NaOH treatment have a significant impact on the composite properties. The date palm frond reinforced polypropylene composites could serve as a potential material in broad range of industrial applications in which high strength is not a main design requirement.
Experimental Study on the Adhering Fuel Film of the Impinged N-Butanol-Diesel Blends
Authors: Zhang Hongsheng , Liang Xingyu , Yu Hanzhengnan , Wang Yuesen , Weijian Chen
Published: February 2017

In this paper, the characteristics of the adhering fuel film after a spray impingement for the n-butanol-diesel blending fuels have been investigated under different injection pressures (60MPa, 80MPa, 100MPa, and 120MPa) and impingement angles (45°, 60°, 75° and 90° ). The blending fuels include the n-butanol (10%)-diesel (90%) volume ratio (B10), the n-butanol (20%)-diesel (80%) (B20) and the n-butanol (30%)-diesel (70%) (B30). The applied diesel is the commercial No. 0 diesel fuel. A cold rolling flat steel plate with a dry surface (Dry wall) and a plate coated with lubricating oil on its surface (Wet wall) were used as an impingement wall. Adhering ratio of each impinged fuel was calculated from the measurement with a precision balance, the adhering fuel film morphology data were captured using an oil film thickness measurement instrument. All experiments were conducted through a common-rail high-pressure fuel injection system where a single-hole nozzle is employed under the normal temperature and pressure. The experimental results demonstrate that the increase of the injection pressure leads to a lower adhering fuel ratio and a smaller distribution of the thick film regions. Meanwhile, with the reduction of the impingement angle, the oil on the wall shows the shape of droop with a thinner fuel film and the adhering fuel ratios decline gradually. The ratio of the adhered oil of B30 is lowest among the three blends, but the difference of their mean thickness on the wet wall is not huge and there is a large central thinner area for the film of B20 on the dry wall which means the faster rate of evaporation.
A Search Space Reduction Method for Optimizing Sequential Control by Hypothetically Achievable Bound Estimation of the Objective Function
Authors: Tokuda Yuya , Yoshida Yasuhiro , Sekiai Takaaki , Yamanaka Kazunori , Yamashita Atsushi , Iyanaga Norihiro , Katagiri Yukinori , Yoshida Takuya
Published: February 2017

Metaheuristic methods such as genetic algorithm, simulated annealing, and artificial bee colony algorithm methods take much time to obtain an optimal solution, particularly when a large scale simulator is employed for estimating the state of the environment.

In this paper, a search space reduction method for accelerating the optimization of sequential control systems is proposed. The proposed method estimates a hypothetical achievable bound of the objective function and uses it as the prior knowledge to reduce the search space. The hypothetical achievable bound is estimated using the fact that large scale plants consisting of multiple components are in many cases controlled in a sequential manner.

The size of the search space reduction obtained by the proposed method is evaluated by an example problem that minimizes the start-up time of a thermal power plant. As a result, the size of the search space is reduced by 65%. The proposed method does not lose the optimality of the optimization method to be accelerated. In addition, this method is also applicable to optimization problems other than sequential control if the hypothetical achievable bound of the objective function is estimable without measuring the state of the environment or using the simulator.
Solar Selective Volumetric Receivers for Harnessing Solar Thermal Energy
Authors: Khullar Vikrant , Tyagi Himanshu , Otanicar Todd P. , Hewakuruppu Yasitha L. , Taylor Robert A.
Published: February 2017

Given the largely untapped solar energy resource, there has been an ongoing international effort to engineer improved solar-harvesting technologies. Towards this, the possibility of engineering a solar selective volumetric receiver (SSVR) has been explored in the present study. Common heat transfer liquids (HTLs) typically have high transmissivity in the visible-near infrared (NIR) region and high emission in the mid-infrared region, due to the presence of intra-molecular vibration bands. This precludes them from being solar absorbers. In fact, they have nearly the opposite properties from selective surfaces such as cermet, TiNOx, and black chrome. However, liquid receivers which approach the radiative properties of selective surfaces, can be realized through a combination of anisotropic geometries of metal nanoparticles and transparent heat mirrors. Solar selective volumetric receivers represent a paradigm shift in the manner in which solar thermal energy is harnessed and promise higher thermal efficiencies (and lower material requirements) than their surface-absorption based counterparts. In this paper, the ‘effective’ solar absorption to infrared emission ratio has been evaluated for a representative SSVR employing copper nanospheroids and Sn-In2O3 based heat mirrors. It has been found that a solar selectivity comparable to (or even higher than) cermet-based Schott receiver is achievable through control of the cut-off solar selective wavelength. Theoretical calculations show that the thermal efficiency of Sn-In2O3 based SSVR is 6 to 7% higher than the cermet-based Schott receiver. Furthermore, stagnation temperature experiments have been conducted on a lab-scale SSVR to validate the theoretical results. It has been found that higher stagnation temperatures (and hence higher thermal efficiencies) compared to conventional surface absorption-based collectors are achievable through proper control of nanoparticle concentration.
Numerically Determining Material Coefficients of Micro-Injection Molded PVDF/PZT Piezoelectric Composites With Controlled Filler Orientation
Authors: Yang Can , Yin Xiao-Hong , E Shiju , Kan Junwu , Zhang Zhonghua , Liang Dong
Published: February 2017

In the present work, novelly structured poly(vinylidene fluoride)/lead zirconate titanate (PVDF/PZT) piezoelectric composites with controlled filler orientation were designed. The material coefficients of the proposed composites including elastic stiffness constant (C), piezoelectric constant (e) and dielectric constant (ε) were numerically determined. Specifically, the Comsol Multiphysics connected with Matlab was utilized to create the unit cells representing the piezoelectric composites. In the calculations, the whisker-shaped PZT content was varied in a relatively low range of volume fraction (i.e., 0.3∼3.5 vol.%). Furthermore, the PZT orientation and PZT length-reduction were considered in order to simulate the flow-field effect of micro-injection molding (μIM). The results showed that using a low PZT content was effective for modifying the composite’s material coefficients. In addition, the PZT orientation was identified as an important factor influencing the composite’s properties, which was believed to result from the apparently changed amount of the PZT whiskers along the direction of interest. Finally, the effect of the PZT length-reduction during μIM was found insignificant, which suggests that μIM can be safely adopted to fabricate PVDF/PZT piezoelectric composites taking full use of its advantages such as high efficiency and low cost, without worrying about PZT’s length-reduction.
On the Stability Analysis of Active Magnetic Bearing With Parametric Uncertainty and Position Tracking Control
Authors: Kato Junya , Takagi Kentaro , Inoue Tsuyoshi
Published: February 2017

This paper considers effect of the parametric uncertainty of an active magnetic bearing which is used to control a rigid rotor. In the feedback control law, PD control and feedback linearization is used. Firstly, this paper shows that one of the two uncertain parameters in the electromagnet model significantly affects the stability of the system. Moreover, this paper analytically shows a method to select the nominal value of the critical parameter affecting the stability. Next, while the shaft is rotating, this paper considers reducing vibration due to rotating unbalance by inversion-based disturbance observer and controlling position by feedforward control, besides PD control and feedback linearization. Based on the linearized model, this paper shows the performance degradation caused by the parametric error and investigates the tracking error experimentally. Finally, in order to improve the tracking performance under the existence of the uncertain parameters, this paper proposes to employ an inversion-based feedforward controller designed from the augmented control object, which includes the controlled object (rigid rotor and magnetic bearing), the disturbance observer and the feedback linearization. The experiment of tracking control of the rotor position is carried out to demonstrate the effectiveness of the proposed method.
Numerical Study of Turbulence Nanofluid Flow to Distinguish Multiphase Flow Models for In-House Programming
Authors: Pramuanjaroenkij Anchasa , Tongkratoke Amarin , Kakaç Sadık
Published: February 2017

Fluid flow with particles are found in many engineering applications such as flows inside lab-on-a-chips and heat exchangers. In heat exchangers, nanofluids or base fluids mixed with nanoparticles are applied to be used as the working fluid instead of the traditional base fluids which have low thermal-physical properties. The nanoparticle diameters are in the range from 1 to 100 nanometers are mixed with the traditional base fluids before they are applied inside the heat exchangers and the nanofluids have been proved continually that they enhance heat transfer rates of the heat exchangers. Turbulent and laminar nanofluid flows have shown different enhancements in different conditions. This work focused on comparing different turbulent nanofluid simulations which used the computational fluid dynamics, CFD, with different multiphase models. The Realizable k-ε turbulence model coupled with three multiphase models; Volume of Fluid (VOF) model, Mixture model and Eulerian model, were considered and compared. The heat exchanger geometry in the work was rectangular as in the electrical device application and the nanofluid was a mixture between Al2O3 and water. All simulated results, then, were compared with experimental results. The comparisons showed that numerical results did not deviate from each other but their delivered-time consumptions and complications were different. If one develops his own code, Eulerian model was the most complicated while Mixture model and Eulerian model consumed longer performing times. Although the Eulerian model delivered-time consumption was long but it provided the best results, so the Eulerian model should be chosen when time consumption and errors play important roles. From this ordinary study, the first significant step of in-house program developments has started. The time consumption still indicated that the high performance computers should be selected, and properties obtained from the experimental studies should be imported to the simulation to increase the result accuracy.
Characterization of Biodiesel Produced From Terminalia Seed Oil and Engine Performance Evaluation With 10% and 20% Blending
Authors: Kumar Gogoi Tapan , Kakati Jyotirmoy
Published: February 2017

In this article, biodiesel produced from Terminalia seed oil is characterized. Oil content in Terminalia fruit seed was found to be 46.0%. Free fatty acid (FFA) content in Terminalia seed oil was 6.0%; hence a twostep acid base catalyzed transesterification process was used for producing biodiesel from the Terminalia seed oil. Terminalia seed oil contains 23.47% palmitic, 8.04% stearic 37.90% oleic and 20.97% linoleic acid. Calorific value, kinematic viscosity and density of Terminalia fatty acid methyl ester (FAME) were 39.594 MJ/kg, 5.49 mm2/s and 890.6 kg/m3 respectively. Most of the fuel properties of Terminalia FAME meet ASTM D6751 and EN 14214 biodiesel standards. Cetane index, fire point and pour point of Terminalia FAME were found to be 54.92, 172°C and −1°C respectively. Further, an engine performance study with 10% (B10) and 20% (B20) blending of Terminalia FAME with diesel fuel shows higher brake specific fuel consumption (BSFC), lower brake thermal efficiency (BTE), higher peak pressure and early pressure rise in case the blends compared to petroleum based diesel fuel. Terminalia seed thus could be potential feedstock for biodiesel production and its 10% blending with conventional diesel fuel could be used in engine without compromising with the engine performance.
Dynamic Simulation of Large Flow Solenoid Valve
Authors: Liu Z. , Han X. , Liu Y. F.
Published: February 2017

A nonlinear dynamic model of a large flow solenoid is presented with the multi-physics dynamic simulation software called SimulationX. Validation is performed by comparing the experimental results with the simulated ones. The dynamic characteristics of the large flow solenoid valve are analyzed. Different structural parameters are modified in this research and the diameter of the orifice is proved to be one of the most important parameters which influences the pressure response most.
Influence of Basic Parameters for Fiber Reinforced Polymer Crushing Simulation
Authors: Stalin Benoit , Yang Dongyang , Xia Yong , Zhou Qing
Published: February 2017

This article investigates the influence of finite element model features on Fiber Reinforced Polymer (FRP) crushing simulation results. The study focuses on two composite material tube models using single shell modeling approach. The chosen material model is MAT58 (*MAT_LAMINATED_COMPOSITE_FABRIC) from the commercial finite element analysis software LS-Dyna. The baseline models geometry and material parameters come from a model calibration conducted for lightweight vehicle investigation. Five parameters are investigated. The mesh size and the number of integration point (NIP) are generic and ERODS, TSIZE and SOFT are the non-physical parameters of MAT58. This analysis aims at discuss the influence of these parameters on the simulation results focusing on the initial force peak and the average crush load, regarding results realism and instabilities such as large elements deformation and abnormal peak values. Also, the impact of the number of CPUs involved in the simulation calculation is presented. Recommendations are given to set the mesh size and the NIP. TSIZE value should be selected regarding the simulation time step. On the other hand, ERODS has to be adjusted manually. Both are determinant for simulation robustness. Further studies are proposed to find out the reasons of large element deformation.