Mechanical Engineering

In present research, acoustic signals from gearbox of Massey Ferguson 285 are used for fault diagnosis of gears. Worn tooth face gear and broken tooth gear are studied as two common faults in gear-sets. Signal processing on acquired acoustic signals are done using wavelet transform. Decomposition is made using discrete wavelet transform (DWT) in four levels and using Db4 mother wavelet. Desired information from DWT decomposition is provided by applying some functions on DWT outputs. The investigated data set is fed into feed forward back-propagation neural network to classify the gears status. Two layer networks are trained and tested with separate data sets and using variable hidden layer neurons count. Results show that 100% performance is gained by a network with two neurons in hidden layer.

In this paper, a Hybrid approach has been developed by combining Taguchi Method, grey relational analysis method and fuzzy logic, to reap their advantages in the drilling process. Using hybrid approach a single hybrid grade is determined for multiple response characteristics. Drilling experiments has been performed on Al6061 material with coated and uncoated HSS tools under Minimum Quantity Lubrication (MQL) condition. The controllable parameters such as speed, feed, lubricant, tool material and point angle which influence the responses like power, temperature, Burr height, surface roughness are identified. The responses are analyzed using this hybrid approach and optimum controllable parameter combination is identified.

Thermal energy can be stored as latent heat in which energy is stored when a substance changes from one phase to another by either melting or freezing. Paraffin wax has been widely used for latent heat thermal energy storage system applications due to large latent heat and desirable thermal characteristics. Paraffin wax has lower heat transfer rates during melting/freezing processes due to its inherent low thermal conductivity. This paper reviews and summaries the recent experimental and theoretical works on the thermal conductivity enhancement of paraffin wax.

Investigation of the sandwich structures under bending has an important role to understanding the composite structures stability. Bending behavior of sandwich structures has a wide range of applications in science, engineering and technology. In this study the effects of core shape, cell wall height, wall thickness and skin thickness on critical bending load of honeycomb sandwich panels have been investigated. The other parameters of sandwich panel supposed constant during all analyses. The finite element simulation has been carried out with using of ABAQUS software and results were compared with experimental results. After that design of experiment based on Taguchi method has been carried out for understanding the effect of investigated parameters on maximizing the critical bending load. Eventually, the effect of parameters has been investigated with using of ANOVA.

Traditional Rapid Prototyping (RP) is referred to as layered manufacturing free form fabrication. It is used for the physical modelling of a new product design directly from CAD data without the use of any special tooling or significant process engineering. This reduces the lead time required to produce a prototype of product. This paper is related to designing and manufacturing of modified bench vise on rapid prototyping machining process. We have designed the conventional and modified bench vise in Pro-e CAD software and manufactured it on Dimension 1200esRPT machine and analysis is carried out in ANSYS CAE software.

Thermal designing of plate fin heat exchanger explains the heat transfer coefficient, hydraulic diameter, Colburn factor, friction factor, Reynolds number of plate fin heat exchanger. The present review explains the various correlations used in the thermal designing of plate fin heat exchanger. Colburn factor ,hydraulic diameter and Friction factor are the major parameters in the design correlations.

Compressor characteristics, being representations of the compressor pressure ratio as a function of gas flow through the compressor have been studied. Compressors are used in turbochargers to increase the pressure of air and also its density greater than ambient. Choosing the right compressor is very important in obtaining best power output of engine by turbocharging, so it is important to have compressor map for matching turbocharger with a particular engine. Compressor map is drawn by running compressor at varying speeds and mass flows. In this paper compressor characteristics were investigated through CFD analysis.

Refrigeration is the applied science which deals with reducing the temperature of a confined space and its content to a predetermined level that is below the ambient temperature. The design of a cooling table is presented. The cooling table is an innovative application in refrigeration system design. The table is a multipurpose table for maintaining a low product temperature whilst still being able to carry out other activities on the table like a conventional table. The design covers thecompressor, condenser, evaporator, table frame, table top, cabinet volume and the covers. The prototype design requires a 70W compressor for three participants.

Since the inception of industrial revolution, a continuous attempt has been made to recover and minimize the waste heat. In the present research paper review on heat pipe is done. Through heat pipe the hot air is used to pre heat the inlet air of 4 stroke diesel engines. Further, the different performance parameter is calculated for the analyzing the effect of pre heat inlet air in comparison of normal air. Variation of Performance is discussed and salient conclusion is drawn which indicates that, a wide scope is available for further research on heat pipe and especially in the relation of IC engine exhaust heat recovery system to preheat the inlet air.

In this paper experimental investigation has been carried out on kevlar/glass angle ply hybrid composites to characterize interlaminar shear strength. With the aim of determining the influence that the structure, a reinforcement type and a sort of resin exert upon the interlaminar strength. Hybrid composites are considered materials of great potential for engineering applications. One advantage of hybrid composite materials for the designer is that the properties of a composite can be controlled to a considerable extent by the choice of fibers and matrix and by adjusting the orientation of the fiber. The scope for this tailoring of the properties of the material is much greater, however, when different kinds of fiber orientations are incorporated in the same resin matrix. Three orientations viz 0?/90?, ±45?and 60?/30? were considered for studies. Mechanical properties such as interlaminar strength, interlaminar stiffness, & peak load of the hybrid composites were determined as per ASTM standards. Vacuum bagging technique was adopted for the fabrication of hybrid specimens. It was observed that orientation at 0?/90?showed significant increase in ILSS properties as compared to other orientation.