Mechanical Engineering

Majority of refrigerator works on vapor compression refrigeration system. The system consists of compressor, condenser, expansion valve and evaporator. The performance of the system depends on the performance of all components of the system. The main objective of the present study is to study the performance of a domestic refrigerator by placing shell and tube type heat exchanger immediately after the condenser to extract more amount of heat by sub cooling process by using ammonia as an external cooling media.

Mechanical Properties such as tensile strength, yield strength Impact strength etc and microstructure of weldment of various steels are too much affected by the shielding gases. Shielding gases play an important role during the welding process.it cannot be over look. In this review paper an attempt has to be made to explain the effect of shielding gases on the mechanical properties and metallurgical properties of a weldment. The coarse-grained weld microstructure, higher heat-affected zone, and lower penetration together with higher reinforcement reduce the weld service life in continuous mode gas metal arc welding (GMAW). It is observed that weld bead geometry and penetration is too much affected by the use of shielding gas. This brief review illustrates the effect of shielding gases on weld quality

The accusative of this field of study is to build up a more effective research to obtain and to understand the effects and the relation between/on the process parameters depth of cut, spindle speed and cutting feed rate on the surface roughness and to build a multiple regression model and predict the surface roughness values of machining parameters in the end-milling process. By the settling of experiments is to be designed and begin the enactment of surface quality and surface finish for the end-milling process have been performed. This set of experiments can provide brainstorm into the troubles of operating and controlling the finish of machined surfaces when the machining process parameters are aligned to obtain a certain surface finish. The set of experiments and the model, which includes the effect of depth of cut, spindle speed and cutting feed rate, and the interaction between any two-variable, which predict the surface roughness values with an accuracy of about 5.22 %.

Ferrous, non-ferrous metals and alloys are melts and reshape them into finished shape through pouring molten metal into a mold cavity through solidification. The present review confines itself to the literature on the understanding of necessary conditions that are affect the casting properties i.e.grain nucleation, grain growth and other properties of solidified finished shape. After completion of nucleation, solidification process will continue with the growth of nuclei. The number of nucleation sites in casting nucleation and growth of grain refinement can be achieved by increasing the grain refinement is important. In general, finer grain size leads to high mechanical properties such as tensile strength, hardness, toughness, fatigue strength and yield. Mechanical properties and grain refinement can be achieved by the mold rotation, mechanical vibration and electromagnetic stirring. In this paper also review the cooling rate, nucleation presents, grain size, grain growth and solidification behavior change under static and oscillatory casting conditions.

The Mechanical ore handling plant in Goa, India comprises of receiving and shipping section. Receiving section deals with the unloading of ore from barge. This is accomplished by wire rope operated grab un-loader. Since the unloading is being done round the clock, frequent failure of wire rope is observed. The unloading process gets disrupted when the wire rope fails. This results in significant loss in unloading hours. Detailed investigation is carried out to reduce the down time and recommendations regarding maintenance are made in this paper. Details of the maintenance policy model and results and discussions carried out are presented in this paper.

The increased demand for the development of certain materials to be used in aerospace, military and medical industries justifies the execution of an extensive investigation to enhance the properties of such materials, especially the shape memory alloys (SMAs). Copper based SMAs are constantly receiving wide attention due to their low cost and important applications. This work is an attempt to enhance the fatigue life of CuZnAl shape memory alloys. A powder metallurgy technique was adopted to prepare samples. Alloying elements such as vanadium, nickel and germanium were used to improve the mechanical properties. Porosity, SEM, EDS, microhardness, compression and fatigue tests were conducted. Alloying with (0.4%wt.V) results in a significant increase in ultimate compressive strength of (33.6 %) in comparison with the reference sample. The reference (control) sample in this work has a substantial increase in ultimate compressive strength (100%) in comparison with a previously reported value in the literature. A microhardness test supports the ultimate compressive strength result and yields an improvement of (39%). These improvements are reflected positively on the fatigue behavior. The endurance limit of alloyed sample was improved by a factor of (23.3 %) in comparison with the reference sample.

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.

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.

The manufacturing industries is becoming more competitive in recent decade, thus more concern about their operations and management, which makes industries interested in developing modern management system in order to stay competitive in managing their business operations. The present paper discusses the real time implementation of maintenance management discipline for the better performance and availability of the equipment. A particular section is selected, and analysis of OEE and maintenance discipline has shown a remarkable achievement. Six month continuous monitoring of plant by scholar has suggested implementing a maintenance management discipline for continuous performance improvement and maximum availability of equipments.

The mechanical advantage of using composite is high strength to weight ratios which increases their capabilities for aerospace, structural and automobile applications. The epoxy-coated reinforcement (ECR) has gained mainstream acceptance to extend the useful life of highway structures. The volume fraction of reinforcement affects the overall strength a composite and the orientation of fibers in matrix plays a significant role in determining the debonding behavior. The present work focuses on the determination of compressive strength and debonding behavior of steel reinforced epoxy composite with different orientation angles of fibers. The results revealed that among different orientations of fibers, reinforcement at 0° angles shows maximum compressive strength and least debonding than 45° and 90° angle of reinforcement.