Mechanical Engineering

The present paper discusses the development of a Markov model for performance evaluation of water circulation system of a thermal power plant using probabilistic approach. A water circulation system ensures a proper supply of water for smooth working of a thermal power plant. For regular and economical generation of steam, it is necessary to maintain each sub- system of this system to ensure an optimum level of availability. In present paper, the water circulation system consists of five subsystems with three possible states i.e. working, reduced and failed state. Failure and repair rates of subsystems are taken to be constant. After drawing transition diagram, differential equations have been generated. After that, steady state probabilities are determined. The system of equations is solved for steady state availability of the system using Laplace transformation technique. Besides, some decision matrices are also developed, which provide various performance levels for different combinations of failure and repair rates of all subsystems. Based upon various performance values obtained in decision matrices and plots of failure rates/ repair rates of various subsystems, performance of each subsystem is analysed and then maintenance decisions are made for all subsystems. The developed model helps in comparative evaluation of alternative maintenance strategies.

Thermal energy can be stored as latent heat in which energy is stored when a substance changes from one phase to another by either melting or freezing. Paraffin wax has been widely used for latent heat thermal energy storage system applications due to large latent heat and desirable thermal characteristics. Paraffin wax has lower heat transfer rates during melting/freezing processes due to its inherent low thermal conductivity. This paper reviews and summaries the recent experimental and theoretical works on the thermal conductivity enhancement of paraffin wax.

In the present context, the world is confronted with the twin crisis of fossil fuel and environmental degradation. The fuel economy is achieved by efficient combustion inside the cylinder which is possible by uniform mixing of air and fuel in the cylinder. The swirl can be generated in the diesel engine by modifying three parameters in the engine; they are the cylinder head, the piston crown, and the inlet manifold. The objective of the present study is to enhance the swirl effect in the cylinder which causes better performance and reduces the emissions. In this work an attempt is made using fixed curved blade with different inclinations placed before the intake manifold for effective air swirl motion. For this, the experiment is done on Kirloskar AV1 water cooled, natural aspirated direct injection diesel engine with pure diesel.

Biodiesel derived from nonedible feed stocks such as Mahua, Jatropha, Pongamia are detailed to be feasible choices for developing countries including India. This paper presents the results of investigation of performance and emissions characteristics of diesel engine using Mahua biodiesel. In this paper, the blends of varying proportions of Mahua biodiesel and diesel were prepared, analyzed and compared with the performance of diesel fuel, studied using a single cylinder diesel engine. The brake thermal efficiency, brake-specific fuel consumption, exhaust gas temperatures, Co, Hc, No, and smoke emissions was analyzed. The tests showed decrease in the brake thermal efficiencies (BTE) of the engine as the amount of Mahua biodiesel in the blend increased. The maximum percentage of reduction in BTE is 14.3% was observed for B-100 at full load. The exhaust gas temperature with the blends decreased as the proportion of Mahua increases in the blend. The smoke, Co, and No emissions of the engine were increased with the blends at all loads. However, Hc emissions of Mahua biodiesels were less than that of diesel.

Biodiesel with diesel additives have been attaining increased attention from engine researchers in the point of the energy crisis and growing environmental issues. The present work is aimed at experimental investigation of polymer based additive are mixed in different proportions with B15 (15% of Mamey Sapote oil + 85% of diesel) bio diesel. Experiments were done on a 4-Stroke single cylinder variable compression ratio ignition engine by varying percentage by volume of SC 5D additives in diesel-biodiesel blends. Their emissions and performance results are compared with base fuel B15 bio diesel. By mixing of this additive, it is observed that cetane index number is increased. The tests conducted at full load and varying speed conditions. At full load for B15 with 2500: 5 ml blend shows that the results of HC, NOx, C0 & smoke density are reduced by 10%, 24%, 16% & 11.12% respectively. Brake power is increased 2.19% whereas brake specific fuel consumption is decreased by 9.09% and for B15 with 2000:3 brake thermal efficiency increased by 4.16%.

Wire electrical discharge machining (WEDM) own benefit in manufacturing of modern materials, particularly used in the space engineering technology as well as in therapeutic industries. With WEDM advancement, complex components can be able to cut easily those hard to machine with conventional process. Obtained high level of precision component and fine surface finish leads WEDM important, WEDM so perplexing in characteristic, as a result choice of fitting information variables is unrealistic by experimentation process. In any machining process, the machining parameters fundamentally influence quality; cost, time and production rate of a manufactured product. WEDM methodology includes more number of variables that influence its execution. However, in the illumination of the writing study and based on the previous tests, pulse on time, pulse off time, wire pressure, and water pressure are considered for the investigation. In this study, Response Surface Methodology (RSM) is utilized to show relation between the information and yield reactions by using trial information, gathered based on DOE. MRR and Ra were plotted and examined based on impact of information process parameters. Later on the created design can be used for optimization.

Solar energy is an economical alternative for today’s energy demand in comparison with other energies. Solar air heater is used for heating the air which in turn is used for drying the agricultural products. The objective of this paper is to design, develop and perform a detailed experiment and analyze the solar assisted drying system (SADS) for drying tealeaves. Green tealeaves plucked directly from the plantations are soaked in warm water for few minutes. Water is drained out; wet leaves are dried using the SADS consists of drying chamber maintained at a temperature of 55°C and pressure of 3Kg/cm2 through solar collectors. The initial weight of the green tea leaves is of 100 gms, which is reduced to 38gms in an hour.

The fiber reinforced laminate composite plates, because of its outstanding mechanical properties such as high strength, high stiffness with less weight, durability, corrosion resistance, finds many engineering applications. In this work, local failure of plate alone in-between the stiffeners is taken for study. This work compares the buckling behavior of thin fiber reinforced laminate composite plates subjected to axial compression under different types of boundary conditions with different types and different angle of layups. For this purpose graphite / epoxy composite rectangular plate is used for the analysis. Further, by varying the dimension of plate, effect of the aspect ratio of the plate on the buckling strength of plate is also studied. Eigen buckling analysis of ANSYS is used for analysis.

Higher quality and cost effective welds can be achieved by understanding the weld metal properties and influence of welding parameters. Submerged arc welding is preferred process for the higher productivity and better finishing of deposited metal. Welding input parameters have significant role in determining the quality of a weld joint. The joint quality can be assessed in terms of weld bead geometry and weld metal properties. Investigation has been made on influence of welding input parameters on weld bead geometry and metallurgical properties.

In this study, the effects of Lpg–gasoline (10%, 20%, 30% LPG and 100% Gasoline) dual fuels on the performance of a single cylinder 4 stroke spark ignition (SI) engine were investigated. In the theoretical study, the Single-cylinder, four-stroke, Single-point injection system SI engine fitted to a Generator was used. For this purpose, simulations were carried out using AVL Boost Software, without catalytic convertor under constant engine speed (3600 rpm) and varying load conditions. The variations in Performance brake power, Torque, brake specific fuel consumption, and exhaust gasses were examined at varying compression ratios for dual fuel single cylinder SI engine. Variable compression ratio (VCR) technology has long been recognized as a method for improving the fuel economy of SI engines. The results obtained from the use of Lpg–gasoline dual fuel were compared to those of gasoline fuel. The results indicated that when Lpg–gasoline dual fuel were used, the brake specific fuel consumption increased and engine performance parameters such as torque and power increases with increasing Lpg amount in the blended dual fuel. Positive results were obtained at all LPG usage levels in terms of exhaust emissions. Best results were achieved at using 100% Gasoline for exhaust emissions.

The phase change process for energy storage is a complex heat transfer phenomenon and the solidification and melting process make the charging and discharging process entirely a transient heat transfer process. Analytical solutions are not available to evaluate the temperature of the PCM during the charging and discharging process. Hence, numerical methods are to be adopted to solve the governing equations involved during this transient heat transfer phenomenon. Further, the correlations are developed using the results obtained from the regression analysis using the experimental results to provide simple solutions to the practicing engineers. In this study, heat transfer experiments were conducted under different levels of air flow rate, inlet temperature, charging and discharging time according to the central composite rotatable design matrix. Within the design space, heat transfer variables were optimized using response surface methodology (RSM) concept to the required PCM melting temperature and room temperature. Further, optimized results show that the minimum PCM melting temperature of 29.8 ºC and room temperature of 28.6 ºC are obtained at the mass flow rate of 0.06 kg/s, inlet temperature of 31.4 ºC, and discharging time 86 mins by optimizing process parameters.

An extensive review conducted before this study, showed data limitation is the main constrain for multiple regression approach. Thus, new technique has been innovated through bit wear distribution over drilled interval depends on formation fingerprint. Field geological, drilling and logging data collected from three wells located in Blue Nile basin subjected to considerable concentrated analysis. Drilling rate predicted as a function of optimum weight on bit and rotation per minute using Bourgoyne and Young model. The Unknown Bourgoyne and Young coefficients have been determined. Correlations of multiple regressions using Statistica-12.5 software predict acceptable values of nine unknown coefficients. Hypothesis test of predicted coefficients showed over 95% confidence interval which simulated saving in time of drilling by 25%. Out comes was verified through Payzone drilling simulator via simulating actual field observations and re-simulate predicted ROP values. Results revealed the proficiency of predicted drilling rate values. The rate of penetration general equation constructed for each formation; then graphs produced for each formation individually depends on bit type and operational conditions.The methodology and out comes presented in this paper enable prediction of optimum penetration rates directly through accurately produced graphs that is during the well planning period for next wells to be drilled in Blue Nile Basin or other similar formations. This research offers new technique via distribution of drill bits dullness over drilled interval to overcome data limitation constrain. Together with qualitative and quantitative analysis of the optimized results that revealed high potentiality of new technique through both operation and economic benefits on drilling.

Vortex tube is a device that separates pressurized inlet gas into hot and cold streams. Its main applications are in spot cooling. Hence cold temperature of outlet gas, as a response variable, is of much concern for experimentation. There are various input controllable parameters, the values (levels) of which may affect the cold temperature of outlet gas. Some studies were carried out on vortex tube hitherto, considering different input controllable parameters. The present work analyses the effect of five input controllable parameters viz., inlet gas (air) Pressure, Length of the vortex (hot)tube, Diameter of the vortex(hot) tube, Diameter of the orifice / diaphragm, and Diameter of the nozzle on the response variable- Temperature of cold-outlet stream of air. Response Surface Methodology (RSM) approach is used to optimize the response. L-27 Orthogonal Array (OA) is used for experimentation. Response is of “Smaller the Better” type. Regression equation is obtained. All the parameters considered but the Length of the vortex tube, are found to be significant from the Analysis of Variance ( ANOVA ) table. Optimum levels for factors are predicted, confirmatory test is run and the experimental results are validated.

In this paper, a Hybrid approach has been developed by combining Taguchi Method, grey relational analysis method and fuzzy logic, to reap their advantages in the drilling process. Using hybrid approach a single hybrid grade is determined for multiple response characteristics. Drilling experiments has been performed on Al6061 material with coated and uncoated HSS tools under Minimum Quantity Lubrication (MQL) condition. The controllable parameters such as speed, feed, lubricant, tool material and point angle which influence the responses like power, temperature, Burr height, surface roughness are identified. The responses are analyzed using this hybrid approach and optimum controllable parameter combination is identified.

CNC Wire cut electrical discharge machining (WEDM) has become an important non-traditional machining process which is used to manufacture intricate shapes with great accuracy and good surface roughness. Due to large number of process parameters and response characteristics, lots of researchers have attempted to model and optimize the process. This paper reviews the research trends in relation between different process parameters and different performance measures including Surface roughness (Ra),material removal rate (MRR), Dimensional deviation (DD), kerf width (KW) and wire wear ratio (WWR). In addition, this paper highlights different optimization methods and discusses their role in CNC WEDM process.

This paper investigates the development of Al6061/Si3N4 metal matrix composites using stir casting technique and optimize the process parameters in turning based on Genetic Algorithm. In this metal matrix composites Al 6061 alloy reinforced with 3% and 5% weight by volume of Si3N4 particles of mean diameter 75µm was used. Experiments were performed in the CNC lathe by using CNMG inserts at various cutting conditions and parameters such as cutting speed, feed and depth of cut and surface roughness was found at different levels. The optimization of machining parameters was done by using Genetic Algorithm.

This paper outline is an experimental study to optimize process parameters of plasma arc cutting for stainless steel 420. Three process parameters were chosen these are cutting speed, cutting current and torch height. The experiments are conducted based on taguchi’s L9 OA. The objective of optimization is to attain minimum Ra and maximum MRR individually. Regression models for Ra and MRR are developed based on Regression analysis in Minitab 17 Software. The optimal settings is obtained for Ra and MRR by using Genetic algorithm optimization technique in MATLAB R2013a software.

Flow Shop Scheduling is the combinational optimization & NP-hard (i.e. Non-deterministic Polynomial-time hard) problems. In Permutation Flow Shops, the sequence of the jobs is same on all machines. In a Flow Shop Scheduling problem with ‘n’ jobs that should be processed on ‘m’ machines. The job can be processed on at most one machine; meanwhile one machine can be processed at most one job. A significant research effort has been committed for sequencing jobs in flow shop to minimizing the make span. Optimization algorithms such as Simulated Annealing (SA), Genetic Algorithm (GA), Ant Colony Optimization (ACO) & Neighborhood Search have played a significant role in solving small scale flow shop scheduling problems. In this paper a recently developed Teaching Learning Based Optimization (TLBO) is proposed method to solve the flow shop scheduling problems to minimize the make span. The proposed algorithm is tested on Taillard Benchmark problems and results are compared with Palmer’s & CDS Heuristic methods. The results show that the proposed algorithm is efficient in producing optimal solution and simple, easy to understand.

In this paper Taguchi method is applied for determining the effect of process parameters on vortex tube made of Delrin material. An Experimental work is carried out to analyze the performance of vortex tube with five controllable input parameters namely diameter of the orifices, diameter of the nozzles, length of hot tube, tube diameter and inlet pressure. Cold temperature is considered as output parameter. The various parameters like S/N analysis, ANOVA and Optimal Cold Temperature were carried out in order to determine the effects of process parameters and optimal factor settings.

Scarcity of drinking water has been a major problem that most parts of this world are facing since years. Though many methods are there like electric water purifiers, they all are having very high initial and operational cost. Solar still is an exception for this. But, due to its lower yield, it is not yet commercialized. Most of those works to improve solar still efficiency and yield were given emphasize to improve the evaporation rate. But the condensation characteristics are also important. Condensing cover of the solar still and its inclination is one of such areas where detailed study is required. This research paper is intended to find the optimum inclination for the condensing cover for a solar still so as to get the maximum yield.

The combustion process in Internal Combustion engines is greatly influenced by the fuel injected into the chamber and its interaction with the air. Investigation of which involves analyzing injection process from the structure point of view of the fuel spray. In addition, optimizing the spray conditions is highly important in reducing the exhaust emissions and improving the performance and combustion characteristics. The main objective is to optimize various parameters of spray for different blends of biodiesel and injection pressure mainly with respect to Sauter Mean Diameter (SMD), spray tip penetration and spray cone angle using concept of Taguchi and also identifying its contribution using analysis of variance commonly known as ANOVA with the help of ?Minitab 14.0? software where the optimum levels of parameters were found using higher Signal - Noise ratio. Based on the number of trials of experiments, spray images of biodiesel for the different combination of control factors were captured and analyzed. Furthermore performance, emission and combustion characteristics are compared by advancing as well as retarding the injection timing in existing Compression Ignition engine for the optimum condition obtained from the experiments conducted in spray chamber. The higher brake thermal efficiency is attained when it is retarded may be due to lower fuel consumption. Unburned hydro carbon is lower for KB20 due to unstable nature and simple molecular structure. Further, among all the blends KB20 can be considered to the best blend on the basis of spray characteristics.

CNC Wire Electric Discharge Machining is the process of material removal using electrical discharge erosion action, with a wire electrode travelling longitudinally through the work piece. The work piece and wire electrode both are immersed in a dielectric fluid. The relative moving passage between the wire electrode and work piece is controlled by a CNC system that is pre-programmed. The Wire Electrical Discharge Machining performance mainly depends on various machining parameters like generator parameters, drawing parameters and user parameters. But the most prominent parameters are generator parameters as they are very important for sparking principles. Reference Voltage (V), Pulse on-time (Ton), Pulse off-time (Toff) fluid injection pressure mode (Inj), Wire tension (WB), Wire velocity (WS) are the crucial machining process parameters which has influence on the machining performance characteristics such as Material Removal Rate (MRR), Surface Roughness (Ra), Spark Gap (SG) and Dimensional Deviation (DD) while processing / slicing of ingot. Variation in machining performances causes both functional, profit and loss for any manufacturing organisation. Hence, an attempt has been made to study and optimize these machining parameters for minimizing the variations in multiple machining performances and process model (empirical relationship/regression model) between the process parameters (V, Ton, Toff, Inj, WB, WS) and the performance characteristics (MRR, Ra, SG and DD) has been developed. These process model can predict the level of performance that the machine would render for a given set of process parameters, thereby providing prior knowledge of desired machining performance before actually producing the part. The process model is able to show the dependency of machining performance on process parameters, which will be useful for both machine designers and the machine users.

The dynamic behavior of infrastructure development has opened a wide area for research in construction management in general, and maintenance management in particular, globally. Ready mix concrete, which is mostly preferred nowadays, is loaded in a transit mixer, and is transported to the construction site. The concrete is delivered to the construction point by means of a concrete pump. Life of the concrete pump can be enhanced and hence capacity of the plant using effective preventive maintenance. In this paper, optimal time for replacement for some critical components has been established using the approach of reliability centered maintenance. The paper includes the reliability assessment and the details of the effectiveness of maintenance on the system under investigation are reported in the paper.

This paper utilized Taguchi robust design of experiment to obtain the optimum response and optimum setting of control factors affecting the impact strength response of ukam plant fiber reinforced CNSL biocomposite. Fiber Orientation (A), Fiber volume fraction (B) and Aspect ratio(C) are the considered process parameters used in the study. Charpy Impact test was carried out considering Standard L9 orthogonal array for the nine experimental runs and the optimization was done based on a larger is better Signal Noise ratio. Fiber volume fraction had the most significant effect on impact strength response evaluated. The optimum impact strength was captured as 11.12963KJ/m2.

Radiation is a volumetric phenomenon, and all solids, liquids, and gases emit, absorb or transmit radiation. However, radiation is usually considered to be a surface phenomenon for solids that are opaque to thermal radiation such as metals, woods and rocks since the radiation emitted by the interior regions of such material can never reach the surface, and the radiation incident on such bodies is usually absorbed within a few microns form the surface. Finned surfaces are used widely in industries, which due to their high temperature transferring heat by radiation is important. One of the this industry is space application, where the heat is transferred on in the mode of radiation. So, having the least material in very important in this industry. In this paper, Longitudinal fins with rectangular, triangular, concave, and convex profiles have been studied to establish the optimum dimensions based on the least material. The results showed that the concave parabolic has the best performance among other types of fins.

The numerical studies are performed to examine the Micropolar fluid flow past an infinite vertical plate. Finite difference technique is used as a tool for the numerical approach. The micropolar fluid behaviour on two- dimensional unsteady flow have been considered and its nonsimilar solution have been obtained. Nonsimilar equations of the corresponding momentum, angular momentum and continuity equations are derived by employing the usual transformation. The dimensionless nonsimilar equations for momentum, angular momentum and continuity equations are solved numerically by finite difference technique. The effects on the velocity, micro rotation and the spin gradient viscosity of the various important parameters entering into the problem separately are discussed with the help of graphs.

In this paper, numerical performance analysis of jet compressor’s has been carried out using irreversibility characteristics. The various losses that occur in different regions of jet compressor have been quantified and an attempt has been made to increase the efficiency of jet compressor by reducing the losses based on minimization of entropy method. In the present work, new technique has been identified to minimise the momentum difference between the motive and the propelled fluid. This was carried out by forcing the propelled stream using a blower. The geometrical design parameters were obtained by solving the set of governing equations, a CFD package; FLUENT and it has been effectively used to evaluate the optimum entrainment ratio for a given set of operating conditions.

The Navier–Stokes equations, named after Claude-Louis Navier and George Gabriel Stokes, describe the motion of fluid substances. These equations arise from applying Newton's second law to fluid motion, together with the assumption that the stress in the fluid is the sum of a diffusing viscous term (proportional to the gradient of velocity) and a pressure term. For solving a free surface flow problem, the basic governing equations are Navier Stokes equations (N-S equations). Hence the study of methods, used for solving N-S equations is important. There are various methods to solve the N-S equations. The equations are useful as they describe the physics of many things of scientific and engineering interest. The Navier–Stokes equations are also of great interest in a purely mathematical sense.

This contribution aims to validate a newly developed add-on module to a commercial simulation software, which enables the prediction of the microstructure and mechanical properties of aluminum cast alloys under different casting conditions. The simulation of the casting process and the resulting microstructure and mechanical properties, permits a reduction of experimental testing and providing the best solution of process and material selections, thereby making the design and development process more cost efficient. The simulation results are compared with the investigation of the micro structural and mechanical behaviors of an As-Cast Aluminum cylinder head processed by semi permanent gravity die casting. It is demonstrated that the predictions made by the simulations are comparable to the experimental results. In order to further enhance the quality of the simulation tool, it is of significance to gain more experience from comparisons with complex castings of different aluminum alloys, where the microstructure as well as the mechanical properties are carefully evaluated.

In submerged arc welding (SAW), selecting appropriate values for process variables is essential in order to control heat-affected zone (HAZ) dimensions and get the required bead size and quality. Also, conditions must be selected that will ensure a predictable and reproducible weld bead, which is critical for obtaining high quality. In this investigation, mathematical models were developed to study the effects of process variables and heat input on various metallurgical aspects, namely, the widths of the HAZ, weld interface, and grain growth and grain refinement regions of the HAZ. The color metallography technique and response surface methodology were also used.The thermal effect of Submerged Arc that specially depends on the electrical arc, flux type and temperature field of it in workpiece, is the main key of analysis and optimization of this process, from which the main goal of this paper has been defined. Numerical simulation of welding process in SIMPELC method and by ANSYS software for gaining the temperature field of copper, the effect of parameter variation on temperature field and process optimization for different cases of Submerged Arc are done. The influence of the welding parameter for each mode on the dimensions and shape of the welds and on their ferrite contents is investigated.

A thick-walled 90° elbow pipe is of particular interest due to its frequent usage in industrial systems such as chemical processing plants and petroleum refineries. Elastic stress analysis of thick walled pipe elbows using finite element computer software, such as ABAQUS was investigated. The current study shows that the stress level is influenced by the effects of the ratios of bend radius to pipe mean radius (R/ ) and mean radius to wall thickness ( /t) and value of internal pressure. The investigation is limited to include the elastic stresses due to internal pressure and stress variation which was found to be similar to that of a theoretical study reported in the literature. The stress along a thick-walled 90° elbow pipe with the increase in the inner radius, thickness and pressure increases the stress. Based on the variance analysis, the predictive models in this study are believed to produce values of the elastic stress of a thick-walled 90° elbow pipes close to those readings recorded numerically with a 96.5% confident interval.

The use of non edible oils blend in direct injection diesel engine shows its potential to reduce or control the NOx emissions. Combustion analysis of non edible and non edible blends revealed that the blends had a shorter ignition delay than diesel alone, at both full and light load, and a lower premixed burn fraction at full load. However, the diffusion burn rates were similar. The shorter ignition delay due to high cetane number of non edible oil blends has been suggested as being one of the causes of NOx increase the peak pressure and temperature increase in flame temperature in either pre mixed or diffusion burn has been followed by subsequent increase in NOx emission. This was due to reduction of carbonaceous soot concentration. The performance characteristics of an engine such as brake thermal efficiency, brake specific fuel consumption, brake power and engine torque were not much affected, up to a blend of 20% with neat diesel. The Co and particulate emissions were found to be decreasing with the % increase in blend with a subsequent increase of NOx. Thus the blending of fuel is being limited to 20% in majority of cases to obtain optimum performance and emission characteristics. This paper suggests about by using various types of non edible oils as fuel and blends directly in diesel engines by modifying properties by injecting or Trans-esterification.

Visco- Elastic Plates are being increasingly used in the aeronautical and aerospace industry as well as in other fields of modern technology. To use them a good understanding of their structural and dynamical behavior is needed. In the modern technology, the plates of variable thickness are widely used in engineering applications. The present work is to develop for the use of research workers in space technology, mechanical sciences and nuclear energy where certain components of the structure have to operate under the elevated temperature. The aim of present paper is to study the bi-linearly thermal effect on vibration of visco-elastic square plate whose thickness varies parabolically in x-direction. A frequency equation is derived by using Rayleigh-Ritz technique. Two modes of frequency are calculated by the latest computational software for the various values of taper parameter and thermal gradient.

This paper presents a hybrid optimization approach for the determination of the optimum laser welding process parameters which minimize the weld bead width and maximize weld bead depth together in pulsed Nd:YAG laser welding of thin plates of SS 304 having thickness 2.9 mm. An exhaustive experimental study has been conducted with various process parameters like, pulse width, pulse height, stand-of distance, frequency, welding speed, gas flow angle and gas flow rate. Each of the parameters has three levels. Thus, an orthogonal array L18 has been adopted to accommodate all the above factors at their respective levels. The weld bead width and the weld bead depth are considered as process performances. A multi-response optimization has been carried out by using grey relational analysis (GRA). Also the significant process parameters have been found out for the above process optimization by performing an ANOVA.

Manufacturing industries aims at the reduction in usage of cutting fluids to combat Environmental and Ecological issues towards which new techniques are being explored. Hard turning with minimum quantity lubrication is one such technique which can abate the pollution problems associated with the cutting fluids. The present paper deals with the experimental investigation in turning of hardened AISI D3 steel with CVD coated indexable inserts under minimum quantity lubrication using vegetable oils as cutting fluids. An orthogonal array, analysis of variance(ANOVA) and Deng’s index are applied to study the performance of input parameters such as insert style, cutting fluid, cutting speed, feed and depth of cut by considering quality characteristics such as surface roughness, material removal rate, interface temperature, specific energy and flank wear. Finally a clear presentation is made for Deng’s method

This paper presents effective method and to determine optimal machining parameters in a turning operation on annealed Beryllium copper alloy to enhance the metal removal rate and minimize the surface roughness. The scope of this work is extended to Multi objective optimization. Response Surface Methodology is opted for preparing the design matrix. Artificial Neural Networks are used to train and validate the data prepared through experimentations. Multi Objective Genetic Algorithm is used for optimization of the performance measures of the process. A powerful model would be obtained with high accuracy to analyse the effect of each parameter on the output. The input parameters considered in this work are cutting speed, feed and depth of cut.

In the realistic situation, the total expenditure on the inventory may be limited to certain extent for a store house to maintain inventory of multiple items having independent ordering costs and holding costs. That is, less than a predetermined maximum permissible amount which may be vague to certain extent. In fact all the parameters in an inventory model are normally variable, uncertain and imprecise. These fuzzy variables like objective goal, costs and constraints are considered with linear and parabolic membership functions in fuzzy logic and the model is solved by fuzzy non-linear programming method using Lagrange multipliers and illustrated with numerical examples.

Some physical properties of the rough rice were studied at 10.29, 15.37, 20.5, 25.4, and 30.6% d.b. moisture contents. The length, width, thickness, equivalent diameter, and sphericity increased linearly from 10.63 to 10.82 mm, 1.96 to 2.14 mm, 1.82 to 1.99 mm, 3.34 to 3.55 mm, and 31.52 to 33.24%, respectively, as moisture content increased from 10.29 to 30.6% d.b. In the same moisture range, the one-thousand grain mass, grain volume, surface area, and angle of repose increased linearly from 21.34 to 25.04 g, 20.62 to 24.16 mm3, 34.45 to 38.36 mm2, and 28.54º to 39.41 º, respectively. Results showed that the bulk density, true density, and porosity increased linearly from 480.32 to 499.12 kg/m3, 945.71 to 1131.02 kg/m3, and 49.21 to 55.87%, respectively, with increasing moisture content. The static coefficient of friction varied from 0.479 to 0.732 over different structural surfaces in the specified moisture content range. The specific heat capacity varied from 1654 to 2517 J/kg K in 50, 60, 70, and 100 ºC particles temperatures and for the specified moisture content levels.

A Study on moisture management properties for Polyester with Bamboo Biply knitted fabrics has been reported. The polyester (80 D), Bamboo yarn (30s and 40s Ne) were selected to produce the Biply rib knitted fabrics with various areal density, thickness and tightness factors to analyze the moisture management properties of fabrics. It was observed that polyester with bamboo Biply knitted fabrics have higher air permeability than the polyester with cotton Biply knitted fabric. It is also observed that there is a significant difference between water vapour permeability of polyester with bamboo and polyester with cotton Biply knitted fabrics. It is also found that the polyester with bamboo knitted fabric has better wicking rate than the polyester with cotton Biply knitted fabrics. This Polyester with Bamboo Biply knitted fabrics materials can be used to prepare the composite materials.

Solar parabolic trough collectors are the most useful technology that directly supports renewable energy for conventional energy for water heating. But it is observed that due to ambient temperature many convective losses occur which effects the temperature variation. This article shows the practical work for increasing temperature to cover it by thin transparent glass plate which creates the oven effect and decreases its convective losses which increases the temperature and finally it increase its efficiency.

Ultrasonic waves are used widely in food production, industry and chemical reactions. For conducting such a reactions, it is need to have a reactor in which liquid is affected by the waves. Among the most important parameters used for reactor design, the reactor dimensions may be considered as the most important parameter that can take influence the most, from the wave cavitation. In this study, effects of ultrasonic power, horn diameter and horn height on the amount of energy absorbed by liquid in reactor were evaluated and models were further developed for estimating the absorbed energy. Statistical analysis indicated that the effects of input power, reactor diameter and reactor height were all significant on energy absorption (P<0.01). The results revealed that as the horn diameter increased from 70 to 100 mm, 9% decrease was occurred in the absorbed energy. By increasing the horn height from 30 to 70 mm, 11% decrease was observed in the energy absorption. There was an 11% increase in the energy, together with an increase in ultrasonic wave power from 100 to 300 W. It was also concluded that the second order model was most suitable to predict the amount of energy absorbed by liquid (R2=94.5%).

Chemical vapour deposition (CVD) is a widely used method for depositing thin films of a large variety of advanced materials. Applications of CVD range from the fabrication of microelectronic devices to the deposition of protective coatings but also optoelectronic films, decorative coatings.

All welding processes are used with the aim of obtaining a welded joint with the desired weld-bead parameters, excellent mechanical properties with minimum distortion. The welding input parameters play a significant role in obtaining excellent mechanical properties with minimum distortion to get a desired weld bead parameters. Usually, the desired welding parameters are determined using traditional methods like welder’s experiences, charts and handbooks (preferred values) which are simple and inexpensive. But this does not ensure that the selected welding parameters result in satisfactory welding and this method is not applicable to new welding process. To achive desired weld bead parameters different models were developed to correlate input variables with output variables. Mathematical models to specify the relationship between the input variables and output parameters can be used for optimization. Design of Experiment (DoE) technique has been used to carry out such optimization. Computational network & evolutionary algorithms have also grown rapidly and been adapted for modeling and optimization of welding process parameters to achieve desired properties in the welded joint. In this paper a comprehensive literature review of the application of these techniques is presented. This review shows the correlation and modeling between the input welding process parameters and the output weldment characteristics. The paper also presents the optimization of the different welding processes through the mathematical models and evolutionary algorithm. The use of mathematical models and evolutionary algorithm for the optimization of the different welding processes is discussed in this paper.

In recent days, the Fiber Reinforced Composites have replaced many of the engineering components and the composite material manufacturing area is experiencing substantial growth. FRC’s also have replaced materials used in the civil construction area, sporting goods, automobile and aircraft parts, and boat and ship hulls. The composites in general, offer many advantages over homogenous materials like high strength to weight ratio, less weight, flexibility in design, structural and dimensional stability, corrosion and wear resistance along with low tooling cost. Because of the anisotropy in nature, machining composite materials is a complex process especially operations involved in in drilling and milling. Therefore, dry drilling operation on composite materials affects the performance of the drill tool. Hence the present investigation focusses on the study of effect of the machining parameters such as spindle speed (1200, 1500 and 1800 rpm), feed rate (0.1, 0.2 and 0.3 mm/rev), drill diameter (6, 8 and 10mm) on HSS drill tool wear in the drilling of Glass Fiber Reinforced Polyester (GFRP) composites. The present work also aims to optimize the machining parameters in drilling to get minimum flank tool wear. The experiment is designed using full factorial design of experiments. Measure of land width was used to assess the Flank wear of HSS drill. The process parameters are optimized to reduce the tool wear using Response Surface Methodology (RSM). Mathematical model was generated by through regression analysis by developing a Regression equation for flank wear of HSS drill.

A micromechanical 221 MHz silicon resonator is designed and demonstrated. The vibration mode can be characterized as a 2–D plate expansion that preserves the original square shape. The prototype resonator is fabricated of single-crystal silicon by reactive ion etching a silicon-on-insulator (SOI) wafer. The measured high quality factor and current output make the resonator suitable for reference oscillator applications. An electrical equivalent circuit based on physical device parametersis derived and experimentally verified.

Extensive studies were investigated Mechatronics of Automobile since the synergistic combination of classical electro-mechanic of automobile , computer science and automatic engineering were integrated to together at the beginning of the conceptual stage for the design of new models of automobile. More automobiles involve more pollution after fuel consumption. Although motors’ performance had been proving through its electronic computerized control unit, also called calculator, the limitation and the insufficient functional problem of motor’s injection system remain unsolved. To overcome this problem at different angle in contrast with early studies and conclusions, this paper focuses on motor’s electronic computerized control unit, such as Motronic injection system performance to highlight limitation and insufficient of motor’s injection system by using requirement and constraint analysis of electronic system on the sensors, calculators and injectors before the consequences of the failures of Mechatronics key elements in the motor’s injection system. The results show that electro-chemistry constraints, hardware and software requirements .This paper support the hypothesis that hybrid engine is more perfect for reducing fuel consumption and avoiding harmful gas emission than an internal combustion engine or an electric motor one alone .

The environment friendly natural fibers used in this study are taken from leaf stalk portion of palm tree. Portions of these fibers are alkali treated while the remaining kept raw. Both these fibers are sandwiched separately with glass fibers to form two set of plates by reinforcing into polyester resin matrix blend with coconut shell powder using hand lay-up method. Specimens are tested as per ASTM standards. The results reveal that alkali treatment improved fiber quality and a novel composite was developed to producing automobile parts.

This paper reveals the mechanical and metallurgical properties of the dissimilar joints of AA2024 aluminium alloy and commercial grade copper alloy fabricated by diffusion bonding process. Three diffusion bonds with varying diffusion layer thickness were fabricated and study the effect of diffusion layer thickness on mechanical and metallurgical properties. Mechanical properties such as lap shear strength, bonding strength and hardness are evaluated, Metallurgical characteristics such as diffusion layers thickness, phases in diffusion layer, elemental composition of diffusion layers were analysed. From this investigation, it is found that the diffusion bond with a medium diffusion layer thickness (in between very minimum to very maximum) exhibits superior mechanical properties.

In this work the void fraction for oil-water mixture are measured by using radiation source 137Cs with activity of 0.636 µCi. The plastic-tube contain the mixture are putting interior beaker and subjected into radiation to measure the void fraction. There are many applications industries, such as, oil and gas pipelines, heat exchangers etc.

Analysis of Reversed Hazard Rate (RHR) can provide insights in making it suitable for industrial applications. From the published literature it is learnt that Nature of reversed Hazard rate for standard continuous distributions is a decreasing function. Obviously this makes RHR suitable in the field of maintenance engineering to address hidden failures in a given system. One of its most useful applications lies in the assessment of waiting time of hidden failures. RHR is closely related to another important concept known as the mean waiting time. This concept is useful in casualty insurance, reliability, and medicine including forensic science to predict times of occurrences of events. For instance, the incubation times of diseases, are difficult to measure because the infection time is unobserved in general. Mean waiting time will offer its great help in such situations, which are analyzed and incorporated appropriately in this paper.