Mechanical Engineering articles list

Lightweight materials are increasingly being used in engineering applications today. Composites are replacing traditional metallic materials in a variety of sectors, including aerospace, defence, and aircraft production, where there is a demand for structural materials with high strength-to-weight and stiffness-to-weight ratios. Natural fibre composites are also increasingly used in place of synthetic fibre composites in a variety of technical fields due to their affordability and environmental friendliness. In this particular study, Kevlar (Aramid fibres) is combined with other materials to improve the mechanical characteristics and impact resistance of composites. The only material that costs more than Kevlar is carbon fibres. The goal is to maximize mechanical qualities while utilizing the fewest amounts of pricey Kevlar fibres possible. The hand layup technique was used to create the hybrid composites, which included both natural and Aramid fibres. The performance of various mechanical properties was then assessed. In addition, a morphological examination was done to look at the interior structure of the composite materials that were examined. The results show that the hybrid composite, with or without the addition of nanoparticles, demonstrates great strength with little reliance on Kevlar fibres.

Boopathy Govindarajan

Inlet valve in an engine tends to be subjected to immense thermal loads besides chemical corrosion. Opening and closing of inlet valve practically could be in the order of 2000 times per 1.6 km. In the mean time of engine working cycle, seat insert of the inlet valve is the surface, against which an intake valve seats. Conventional engine valves are provided with a curved angle for its seating position, but for this study, the same is proposed to be positioned at a tapered angle. This tapered position as converted into radius in order to permit rich air at the inlet and reduce exhaust emission. This study is to investigate the nature of the future redesigned Scooping valve for a 1.25L 4-cylinder Petrol engine with VTVT (Variable Timing and Valve Train) under combined mechanical and thermal loading cycle by feeding the input conditions for this study after NX-CAD modelling in ANSYS 10.0 software and the numerical results thus obtained are recorded for future valve design considerations.

Boopathy Govindarajan

Tremendous growth has been incorporated in the field of composite materials in the current scenario where the engineering applications are highly demandable. Currently composites are being used to replace conventional metallic materials in a wide range of industries including aerospace, defense, aircraft, and textile which require structural materials with high strength-to-weight and stiffness-to-weight ratios. Also natural fiber composites are currently replacing synthetic fiber composites of different applications in various engineering industries due to their low cost and eco-friendly in nature. In this work, twisted kenaf, and twisted kevlar (aramid fibers) have combined together to enhance the mechanical properties and also to improve high impact resistance with less contribution of kevlar which is very high in cost categorized next to carbon fibers. Here, the hybrid composites (natural and aramid) are done by using hand layup method, and various mechanical properties have been investigated. Also, the morphological analysis is done to observe the internal structure of the tested composite. It is observed that hybrid composite has high strength with minimum contribution of kevlar fibers.

Boopathy Govindarajan

Production process in the manufacturing industries has proven wasteful of the resources in the production process over time. integrating of lean principles in the manufacturing activities has brought notable success in a complex and slow production process in an industry. This study aims at integrating of lean principles to a product development process to eliminate break down cases as it makes the process easy as well as speeding up the product development in an automotive industry. Three major phases are applied in product development namely; the early concept phase, middle core design and the launch phase. An exceptional definition of products development of lean principles are applied to come up with an analysis framework. Through interviews, observations, documentation and experience barriers that causes large number of wastes can be established. Lean principles will then be applied to eliminate such causes in the product development and then derive conclusion that shows the industry the process of lean in product development in the entire process

Levi P. Cheworei

The increasing usage of composite materials has immersed simpler techniques for inspecting the integrity of composite structures, as composite materials typically have probability of getting material imperfections. In non-destructive testing, shearography reveals defects in associate object by distinguishing defect-induced deformation anomalies. Non-destructive testing (NDT) methods skit and streamer role in physical characterization of new composite materials and in assessment of their quality and serviceability in structures. Non-destructive testing (NDT), Non-destructive inspection (NDI), and Non-destructive evaluation (NDE) are concerned with the techniques and measurements that provide data on the condition of the materials and structures at the time of manufacturing and in-service.

Boopathy Govindarajan

Shell and tube heat exchanger is the most common type of heat exchanger, widely used in oil refinery and other large chemical process. The energy present in the exit stream of many energy conversion devices such as I. C engines, Gas turbines etc. goes as waste, if not utilized properly. For example, the heat energy stored in the engine coolant can be utilized in a better way by recovering the heat for heating purposes inside the cabin. It is comparatively economical than the existing heating arrangements, which employ conventional heating coils. So, the present work has been carried out with a view to predicting the performance of a shell and tube heat exchanger in the field of waste heat recovery application. The objective of this project is to design a shell and tube heat exchanger and study the flow and temperature field inside the shell and tubes using ANSYS Fluent R14.5. An attempt has been made to calculate the performance of the above heat exchanger with and without baffles for parallel flow configurations, and the results so obtained have been compared.

Boopathy Govindarajan

The establishment of energy-saving and natural resource-saving systems is an important issue and relevant research and development should be accomplished without delay. Making structures lighter is one way to save energy. The study of light metals such as aluminium and magnesium alloys has received much attention. Aluminium alloys are especially attractive because of superior recyclability and workability. However, present structures made of stainless steels cannot be entirely replaced with aluminium alloy structures, taking into account strength, weldability and economics, although it is possible to replace part of a structure with aluminium alloy components. In this case, it is necessary to joint SS 430F steel with Aluminium 6061. Few sound joints have been obtained, owing to the formation of a large amount of brittle intermetallic compounds which were using fusion welding. In the recent years, welding of dissimilar metals by conventional welding techniques has become difficult. The flux used for the welding will create lot of heat which reduces the strength of the welded joints. In order to overcome this, friction welding is more effective in joining dissimilar metals when compared with fusion welding, since it is a solid-state process. Heat is generated in friction welding by conversion of mechanical energy into thermal energy in the interface of work pieces during rotation under pressure. Various ferrous and non-ferrous alloys having circular or non-circular across sections and that have different thermal and mechanical properties which can be joined by the friction welding. Conventional structures made of steel have been replaced by lighter materials, capable of providing high mechanical strength, lower volume of material and good corrosion resistance components such as those used in industries (shipbuilding, light and heavy automotive, electrical, chemical, civil, space and nuclear industry).

Boopathy Govindarajan

Experimental and numerical investigation have been done to evaluate the aluminum agglomerate size in AP/HTPB/Aluminum propellants and compared it with burning rate results. Bimodal AP particle size distribution is considered in the present work. The effect of aluminum size, aluminum content, fine AP size, fine AP/binder ratio and coarse AP size in aluminum ignition, accumulation and agglomerate formation during combustion, typically in their ranges, are focused. The burning rates were found to be higher for the propellants with lower fine AP/binder ratio. The agglomerate sizes for the propellants with 10 % Al was found to be higher than those with 15 and 18 % aluminum. Observing the agglomerate sizes and the burning rate trends, it can be concluded that the agglomerate sizes vary inversely as the burning rates.

Boopathy Govindarajan

Flow control techniques are broadly classified into two types 1.passive control 2.active control. Present paper discuss about the experimental investigation of flow control using passive method on bluff body. Authors also explains about the various flow control techniques used in bluff body aerodynamics. Experimental setup consists of L m span and diameter d of cylinder model. The next model is having strip of cross section 0.01d dia is placed on the cylinder along the span wise distance with equal polar distance around 30o. both the models were kept between four walls in a Reynolds number ranging from 10000 to 15000. The results show that the Cp values changes according to the changes in cylinder roughness.

Boopathy Govindarajan

During the last two decades, the concept of Fibre Metal Laminates (FMLs) has been evolved to find solution to the requirement of improving mechanical properties and reducing structural weight of elemental components of aircraft structures. In this work FML is prepared using Al 2024 by placing alternately with glass/carbon/aramid Fibres. From experimental results of FML shows greater advantage in mechanical properties then aluminium monolithic layer and this composite fibre laminates individual. The FMLs tested in this work were made of 3 layers of 2024 T3 aluminium alloy 0.28 mm thickness and fibre mats. The 5-3/2 laminates of size 300x300 mm with 3 mm thick were prepared using Vacuum Assisted Resin Transfer Moulding (VARTM) in cold compaction and test specimen were cut by using abrasive water jet machining as per ASTM Standards. The adhesion between fibre and metal layer will play a major role in strength of FML. By keeping this in consideration FMLs were prepared without blow holes and capable of withstanding delamination while preparing specimens through water jet and during various tests employed. The fracture surfaces of destructed specimens are studied with help Scanning Electron Microscope (SEM) image. Similarly, the numerical simulation of all the tests were done using Ansys APDL 10.0 Software. It is observed that aramid FML have substantially stronger in longitudinal directions. Hence, more priority given in this paper to investigate tensile strength and fatigue life of aramid FML.

Boopathy Govindarajan