Recent development in Mechanical Engineering

Experimental test set up at laboratory scale was developed for thermal performance testing of flat plate solar air heater with artificial solar radiation intensity; 600W/m2 . A test cell of size 1m × 0.5m × 0.1m was fabricated. Three configurations namely (i) plane absorber under natural convection (ii) Inclined Vporous ribs with conducting side walls under natural convection and (iii) Former under forced convection were tested. Performances of these designs have been analysed on the basis of thermal efficiency and thermal gradient in normal to the base. Thermal gradient was determined by optical beam deviation method using a coherent light source namely 10mW He-Ne laser. Temperature sensors (RTD, PT-100) were also used to validate the optical results of thermal gradient. The overall thermal efficiencies of these configurations are found as 14.91%, 19.93% and 31.6% respectively. Thermal gradient has been found to be reduced with performance enhancement.

Residual stresses generated in tool play a very important role during machining process .The functional behavior of tool can be enhanced or affected by residual stresses. To understanding the residual stress imparted by machining is an important aspect of the overall quality of the part. The main objectives of this paper is develop a numerical approach to predict the near surface residual stresses in cutting tool and work piece resulting from turning of AISI 1006 and validate the model with ANN. The FEM Explicit dynamics is used for calculating the residual stress in real time environment. Total L16 experiments were designed by Taguchi method. Three input factors (depth of cut, cutting speed and rack angle) and two responses (stress and strain) selected for simulation work. Optimizations of process parameters were done using design of experiments (DOE) and analysis of variance (ANOVA) for some qualitative outcome. In this study model equations are also generated for further analysis using linear regression modeling technique using Minitab software. An artificial neural network model is using for the analysis and prediction the responses. On the basis of simulation work tool wear is dependent on rack angle.

In 20 th century, Electronics elements have become most significant part of the regular life. The main heart of electronic element is PCB which supports and manages mostly machines and equipments these days. Therefore manufacturing of board and assembly of electronic elements is one of the crucial and significant objectives for most of the companies. Better life of PCB's depends on electronic elements and its assembly with board. Solder paste is used as adhesive material for assembly purpose. It is deposited on board using stencil and electronic elements are mounted on it and heated for strong bond. This study investigates on factors affecting stencil printing process due to variation in squeegee speed and density of solder paste. This study is based on computational fluid dynamics virtual simulation. Prototype is developed for modelling purpose and simulation software is used to simulate the flow behaviour of solder paste during stencil printing process.

Buildings contribute impact on CO 2 emission and energy consumption. Electric energy consumption in buildings is about 40% of the total energy consumption of India. In this work building simulation technology is used to evaluate a variety of envelope thermal characteristics and low carbon technology in an integrated manner at the early design stage itself to assist the delivering of sustainable green buildings with a high rating of performance and energy consumption. Building simulation enables designer to identify the key energy loads, test their strategies and compare permutation of design strategy in order to optimize the energy consumption. Design Builder (DB) software is used to carry out a series of sensitivity analysis on set of design parameters, with an aim to achieve a comfortable and energy efficient building. Several parametric studies have been conducted to enable building designers to carry out analysis of energy efficient building model related to building orientation, construction, air infiltration, natural ventilation, window type, openings, and lighting. To calculate the energy saving, basic condition of building model is compared with Energy Conservation Building Code (ECBC) building model. Consider basic condition of building is case A and condition of building according to ECBC is case B.

Performance estimation of the axial flow gas turbines under variety of operating conditions like different speeds and pressure ratios has been hampered by lack of reliable experimental data and experiments cost. Simulation of gas turbine is a simple way to reduce testing costs and complexity.Onedimensional (1D) Simulation is a simple, fast and accurate method for performance prediction of turbine with different geometries. In this approach, inlet flow conditions and turbine geometry are known and by considering loss model, the turbine performance characteristics are predicted. In following work, that is based on one-dimensional modelling method, after the presentation of solution algorithm by trial and error method and introduction of different loss models for modelling, this method were examined for a turbo shaft engine and compared with experimental results. Comparison of the results with experimental data shows so good adaptation. Also according to these results, Kacker and Okapuu's developed model gave the closest results to the reference data.

In today's highly competitive business environment, companies require improvement in Production Lead Times, costs and customer service levels to survive. Because of this, companies have become more customers focused. The result is that companies have been putting in significant effort to improve their efficiency. This paper present the practical application of Value Stream Mapping (VSM) tool implement in a bearing industry. A value stream is an assortment of all actions (value added as well as non-value added) that are required to bring a product through the essential flows, starting with raw material and ending with the customer. For drawing current state value stream mapping, all relevant data has been collected and analyzed. Then analysis of current state map has been done for identifying non-value adding activities, in other words waste and suggestions on how to remove or reduce different wastes. From the results achieved by current VSM, it was observable that the two processes Annealing and CNC Machining have higher cycle time and WIP. In order to increase their capacity, their cycle should be reduced. By implementing some lean principles and changes in the production line, the future state map was created and the reduction the different types of wastes reduced. The total processing time was reduced from 409 seconds to 344 seconds.

This paper presents the effect of pressure dam parameters on the static and dynamic characteristics of two lobe pressure dam bearing. The modified Reynolds equation is derived on the basis of micropolar fluid theory. The Galerkin approach of finite element method has been used to solve modified Reynold's equation for carrying out the performance characteristics. The characteristics, which have been calculated for a wide range of dam parameters, have been found to be greatly influenced with the variation of the micropolar parameters. Effect of various dam locations is presented on two micropolar parameter, coupling number (N2) which couples the linear and angular momentum equation, arising the micro rotational effect of the suspended particles in the fluid and characteristics length (lm) which represents the interaction between the micropolar fluid and the film gap.

Surface roughness is the main indicator of technological performances of a component for electrical discharge machining (EDM). EDM process of manganese alloyed cold-work tool steel was modelled. In this paper we used the fuzzy logic (FL) and neural network (NN) to predict the effect of machining variables (discharge current and pulse duration) on the surface roughness of manganese alloyed cold-work tool steel in order to improve and increase its range of application. The experiments are carried out on manganese alloyed cold-work tool steel, processed with electrodes made of copper. The values of surface roughness predicted by these models are then compared. All models show good agreement with experimental results. When compared to the NN and FL models, the NN model has shown a significant forecast improvement. The results indicate that the NN model is an effective algorithm to forecast the surface roughness in EDM.