Mechanical Engineering

In the present work, cost of the weld is minimized by considering the qualities of weld (strength parameters). Welded joints are prepared with Mild Steel plates and M.S electrodes. Strength properties of welded joints like tensile stress, shear stress are found by conducting experiments with Universal Testing Machine (UTM). An objective function is formulated for minimization cost in terms of geometric properties of weld, where as constraints are formulated in terms of strength properties. The optimization procedure involves the selection of the major geometric parameters such as length of weld, height of weld, depth of weld, width of weld and minimization of cost is considered as the design target. In the present work Mat Lab programs of SA and PSO are developed and executed using weld and test data and the results are compared.

The study focused on the design of an acoustic enclosure for 12.5 kVA diesel generator with an objective to minimize the noise level to a moderately loud sound level. Factors which affect noise reduction and heat management were considered. The study revealed that the loss in transmitted sound amounted to 20dB from the initial 95dB without an enclosure, with the insertion loss being 48.6%. The analysis of the transfer of the sound wave revealed that the frequency of the incident wave was lower than the critical frequency of the enclosure, this signifies that the enclosure will not resonate during operation. The heat generated within enclosure is 19280.806kW and this will cause the maximum temperature of the cylinder head to be exceeded. To avert this, acoustic holes where designed to allow a mass flow rate of 0.57kg/sec of air to pass through the enclosure, conducting the excess heat away.

For some specific applications quality of the hole is much of the need and it is defined by its dimensional accuracy at entrance and exit of hole. Laser drilling is an advanced technology in drilling process, known for its accuracy, fastness and cleanliness in material removal to get the accurate hole diameters to the range of 5 microns. It gives the feasibility to drill the holes of very small aspect ratio. Nd: YAG Laser drilling process is an economical and easily regulated conventional drilling process compared to that of WEDM, punching, broaching and other prevalent destructive processes. This laser drilling technology is equipped with advanced features, provides ease of regulating the different input parameters. Some of the many input parameters that are involved in this operation are power, lamp current, pulse width, wavelength, pulse frequency etc., every input parameter has got its influence on output responses. With this consideration, experimentation is carried out selecting austenitic stainless steel known for its wide applications based on central composite design to examine the effect of laser input parameters particularly lamp current, pulse frequency, gas pressure and pulse width, on the quality of drilled holes. In total 31 experimental trials were conducted to get output responses. With response surface methodology (RSM) technique models were simulated for output responses and then compared with adequacy test. It is found that the response surface methodology predicted models are in close agreement with that of experimental values, further using evolutionary algorithms these models can be used for optimization of process parameters. Results are also useful to automate the laser drilling process.

The utilization of wind energy for power generation is becoming increasingly attractive and gaining a great share in the world power market. Wind is one of fastest growing energy source and is considered as an important alternative to conventional power generation. The energy production from a wind energy system depends on many factors namely characteristics of the wind profile, and most importantly, the operational parameters of the wind turbine generator itself. The suitability of a wind turbine to a site involves designing of wind turbine’s operational parameters exactly according to the wind characteristics of the site. The present work is the analysis of energy generation of a 800kW wind project at Belagavi of the state of Karnataka, India. A mathematical model is developed to study the parameters that affect power generation. These include wind speed, air density, pressure, temperature, blade length, pitch angle etc. The study shows that the operational parameters have a direct effect on the power generation. This will lead the developers and researchers to focus on the highest priority parameters for manufacturing and optimizing the new generations of wind turbines. The method can be used in developing stage of wind energy system.

Tremendous heat energy waste in steel plant through ladle, but nobody think over this issue. A Heat Energy Solidification process are simulated for a continuous casting machine and the constructive shape of the liquid pool is predicted considering at different conditions. Heat energy and Solidification model is described for the C.C. of Steel Slabs. The Model has been established on the basis of the technical conditions of the slab caster in the C.C.

Magnetic bearing centrifugal pumps are the latest model of artificial hearts for long-term use. The impeller is the only moving part in these pump which can leads to lower blood damage due to travel through the pump. In this paper computational fluid dynamics as an advanced tool is employed to simulate blood dynamics in a magnetic bearing centrifugal pump. Different simulations are performed for various ranges of device speeds (2000, 3000 and 4000 rpm) and various flow rates (1, 2,3,5,7 and 9 ). As a main performance of the pump, hydraulic pressure rise is investigated. The results show that the pump can generate sufficient pressure due to different physiological activities. Also shear stress distribution specified that stress around the pump’s blades (high potential regions for blood damage) is less than 98 pa which is much lower than critical stress for blood pumps.

Electric discharge machine (EDM) is a modern machining process with various advantages, as a result of which, its use is becoming more and more widespread.Thispaperconcernswith the influence of EDM input parameters (type of electrodes, peak current, pulse-on time and powder mixing concentration) on the induced surface residual stresses. The silicon carbide powder is mixed with the kerosene dielectric in powder mixing EDM (PMEDM) process. The experimental work was designed by using the response surface methodology (RSM). The analysis of variance (ANOVA) was used and regression models were built to predict the surface residual stresses as a response of the process for AISI D2 die steel.Empirical equationswereobtained for predicting the performance of the process.Two type of electrodes were used, the copper and graphite electrodes.The results showed that the minimum tensile surface residual stresses obtained when using the copper electrodeswith pulse current (22 A) and pulse on duration (120 µs). It is concluded that the use of graphite electrodes and kerosene dielectric alone induced minimum residual stresses with pulse current (22 A) and pulse on duration (40 µs) and with(120 µs) when using the kerosene dielectric with SiC powder mixing. The copper electrodes with kerosene dielectric alone induced residual stresses about (5%) lower than when using kerosene dielectric with 5g/l SiC powder and about (14%) lower than with graphite electrodes and (8%) when using the kerosene dielectric alone and with SiC powder, respectively.

There are various types of tests which are to be carried out in wooden furniture such as Chemical Testing, Furniture Flammability testing, Furniture testing for durability and Performance, Furniture Safety Testing, CARB Certification, Children’s Furniture Testing, Furniture Inspection Services, Mattress Testing. Considering the safety aspects of the furniture which is being used from child to the senior citizens it is essential to have reliable and dependable tests to be carried out on the wooden furniture. This paper is aimed at defining the various tests to be carried out in wooden furniture.

Gender differences played an important role in theoretical mechanics to influence students’ learning interests, academic interests and achievements. In order to improve teaching quality and assist students’ learning, we used SPSS to analyze the data of theoretical mechanics test, gained a comprehensive understanding of gender differences on the theoretical mechanics teaching. The findings of the study indicated that the gap of gender difference exists in theoretical mechanics learning. The test showed female students get higher points in theoretical mechanics test. The result of t-test for two groups of male and female students showed that they had significant difference in terms of mean scores obtained in choice questions, calculating questions, particle mechanics and rotating reference frame tests.

In the present day scenario of manufacturing industry, quality and productivity play a significant role. Surface roughness and material removal rate are indicators of quality and productivity as also interface temperature and flank wear are the indicators of tool life. Hence surface roughness, material removal rate, interface temperature and flank wear are considered as response characteristics. This article focuses on an approach based on Grey relational analysis and Desirability function analysis for optimizing the process parameters during turning of AISI D3 steel with CVD coated tool with multiple performance characteristics. Experimentation were carried out on a Conventional lathe using L9 orthogonal array based on Taguchi design of experiments. The influence of spindle speed, feed and depth of cut were analyzed on the performance of surface roughness, material removal rate, interface temperature and flank wear .The optimal turning parameters are determined by composite desirability index and grey relational grade. Analysis of variance(ANOVA) is used to determine the influence of parameters which significantly affect the responses simultaneously. From the study, it is concluded that machining performance is significantly improved.