Mechanical Engineering

Adhesive joints are used in a wide range of industrial applications due to their advantages over other joints. The crack propagation analysis in an adhesive joint is very important for its sustained performance. The Cohesive zone model (CZM) is found to be effective in this area due to its advantage over traditional methods. An overview of the CZM, usage with Finite Element Analysis (FEA), comparison with other methods, and implementation by back face strain (BFS) technique are reviewed in a proportional manner

Sand inclusion is an important defect in Cast Iron castings. On an average this defect is almost thirty to forty per cent of the total defects occurring in a foundry. Sand inclusion is undesirable since it results in reduction in the strength of the casting and bad finish of the casting surface. More than hundred parameters are responsible for sand inclusion and hence it is difficult to control defect during casting. A detailed Literature review of the previous work mostly on sand inclusion for almost last fifty years is done in this paper to find appropriate parameters for defect formation of sand inclusion. From the literature review it is found that the exact remedy for sand inclusion is not easy. The papers describing different techniques like Quality Function Deployment, cause and effect diagram, Design of Experiments etc. are also referred for finding the appropriate parameters responsible for sand inclusion. Corrective action should be taken on responsible parameters to eliminate the defect and improve quality of ferrous castings.

Harvesting solar energy has been the keen focus of study among researchers all over the globe. In the current scenario of fast depleting non-renewable resources, efforts have to be made for maximum utilization of available solar radiations. The present review studies NEILS as one of the front runner as suitable HTF for solar collectors due to their impeccable thermal properties and the various possible reasons for enhancement in heat transfer properties of NEILS.

The objective of the present study is to give a review on heat transfer characteristics of fluids in curved and straight tubes for various parameters and under different experimental conditions. The heat transfer can be increased by two techniques mainly like application of external forces or by modification in surface geometry of the fluid passages. Surface geometry modifications like bending of straight tubes into curved coils are effective and efficient method of heat transfer enhancement. In this paper, various correlations proposed based on experimental heat transfer data by earlier investigators are presented to support the enhancement in overall heat transfer coefficient in curved tube and in straight tube heat exchangers. However, comparison of experimental overall heat transfer coefficient in helical coil and straight tube heat exchangers are found to be limited in the present literature.

Supply of power for an implantable medical device through a thermoelectric generator shows potential way for a biological system. The direct utilization of the temperature difference existing whole biological body is the unique feature. This paper attempts to review the energy generation of an implanted thermoelectric generator for various physiological or environmental thermal surroundings. Also several technical approaches included to enhance the energy generation from an implanted thermoelectric generator, to shows its long-term potential energy supplier for such medical practices.

In modern engine design, to reach a more compact and optimized cooling system, exploiting nucleate boiling in thermally critical regions is required. Several studies have attempted to enhance the nucleate boiling heat transfer. This paper reviews the most important issues (i.e. surface roughness, composition of the liquid, electric field, vibration, orientation of the heated surface, surfactant addition, pressure and velocity) and their effects on nucleate boiling heat transfer.

It is found from the literature survey that very few comprehensive reviews exist on the Performance and emission characteristics of a diesel engine using isobutanol–diesel fuel blends. Some of the important reviews on fish oil with Isobutonal as an additive, diesel with different percentages blend with Isobutonal, butonal- gasoline blends effects on the combustion process in a SI engine have been reviewed. Different Isobutonal blends with base fuels experimental performances including both diesel engine and gasoline engines have been reviewed. An attempt is being made to identify best performing methods from the literature reviewed; this will be a reference for further research. This paper deals with updated review of the literature on performance and emission analysis with Isobutonal blends with diesel and biodiesel under the resource constrained.

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 cohesive zone model (CZM) can be regarded as a computational model which provides valuable insights in the prediction of crack initiation and propagation. The concept behind this model considers the process of fracture as a gradual phenomenon in which separation takes place between two adjacent virtual surfaces across an extended crack tip. The role of the CZM in analyzing the crack propagation in different materials and variations in the traction separation law(TSL) are covered in a detailed manner in this paper.

Environmental and Ecological issues call for the reduction in usage of cutting fluids in metal cutting industry. New techniques are being inquired to achieve this objective. Hard turning with minimum quantity lubrication is one such technique which can alleviate the pollution problems associated with cutting fluids. In the present work, vegetable oil based cutting fluids like castor oil, palm oil and ground nut oil is made to drop at tool-work interface using over-head system. The present paper deals with experimental investigation carried out for machinability study of hardened AISI D3 steel in combination with CVD coated cemented carbide inserts of different styles and to obtain optimum process parameters using Deng’s similarity approach. An orthogonal array, overall performance index and analysis of variance ( ANOVA) are applied to study the performance of process parameters such as insert style, cutting fluid cutting speed, feed and depth of cut with consideration of quality characteristics i.e., surface roughness, material removal rate and specific energy. Finally a clear presentation is made for Deng’s approach