Mechanical Engineering

Tunnels represent a key part of the world transportation system playing a fundamental role both in people and freight transportation, especially in developed countries. Around the world, most major cities and metropolitan areas have metro systems accounting for hundreds of kilometers of underground tunnels and network systems. This study presents the pressure losses in ventilation systems of a long circular tunnel using for a metro purpose length of 700m, and diameter 6.6m, K.M.R.C., Kolkata has been vividly studied and presented in this dissertation. The tunnel which is being driven in the soft soil by using a tunnel boring machine has already developed up to a length of 700m and till the excavation is going on to continue. Auxiliary ventilation is adopted to ventilate the tunnel with the help of an axial-flow fan connected to a duct of approximately 680m in length. The various ventilation related parameters, viz. air quantity, pressure and temperature of the air in various locations inside the tunnel have been studied. In addition, we emphasize the pressure losses in tunnels in various locations i.e., to consider as bend taking place has been calculated. In the Kolkata metro, there is an earth pressure balance TBM is used. EPB excavation provides continuous support to the tunnel face by balancing the earth pressure against the forward pressure of the machine, and the advancement rate is 15 meters every day. In addition, the pressure losses in various tunnel configurations have been computed from the empirical relations as well as computational fluid dynamics (CFD) simulations. The aim of this project work is to correlate the values of pressure losses of analytical results and the computational simulation results with the help of using CFD software and conclude the difference of graph plotted to assess the adequacy of the tunnel and suggest a few measures to improve the ventilation inside the tunnel for building a cordial environment and enhancing the tunneling operation. This study suggests that pressure losses in field study and CFD simulation are approximately the same.

Since the inception industrial revolution, a continuous attempt is being made to recover and minimize the waste heat. With the time various waste heat recovery system is developed. In the present research paper an exhaustive review on heat pipe is done. Various aspects and application is described and the view of authors is presented here. Further, the wide application of heat pipe to recover waste heat from the exhaust of IC engine id 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.

There is a growing demand for the need of alternative fuels for transportation. Increasing the efficiency and reducing the exhaust gases in engines have been dominant in the fields of research. The exhaust gases contain numerous pollutants that are extremely harmful though in chronic conditions. Hence, Electromagnetic engines were created that uses the combined power of an electromagnet as well as a permanent magnet. While these engines have already proven their worth as alternative sourced engines, non-polluting and eco-friendly, the current challenge is to make them more efficient, reliable and cost effective.

An extensive review conducted before this study, showed data limitation is the main constrain for multiple regression approach. Thus, new technique has been innovated through bit wear distribution over drilled interval depends on formation fingerprint. Field geological, drilling and logging data collected from three wells located in Blue Nile basin subjected to considerable concentrated analysis. Drilling rate predicted as a function of optimum weight on bit and rotation per minute using Bourgoyne and Young model. The Unknown Bourgoyne and Young coefficients have been determined. Correlations of multiple regressions using Statistica-12.5 software predict acceptable values of nine unknown coefficients. Hypothesis test of predicted coefficients showed over 95% confidence interval which simulated saving in time of drilling by 25%. Out comes was verified through Payzone drilling simulator via simulating actual field observations and re-simulate predicted ROP values. Results revealed the proficiency of predicted drilling rate values. The rate of penetration general equation constructed for each formation; then graphs produced for each formation individually depends on bit type and operational conditions.The methodology and out comes presented in this paper enable prediction of optimum penetration rates directly through accurately produced graphs that is during the well planning period for next wells to be drilled in Blue Nile Basin or other similar formations. This research offers new technique via distribution of drill bits dullness over drilled interval to overcome data limitation constrain. Together with qualitative and quantitative analysis of the optimized results that revealed high potentiality of new technique through both operation and economic benefits on drilling.

For the appraisal of contamination of lake waters coliform count is generally used to review the infectivity echelon of potable water. The usual sources of coliform contamination at lake Sambhaji include discharges due to domestic wastes, laundry activities related to hospitals, natural surface runoff, rivulets, swimming activities, anthropogenic activities urban run-off, animal and human wastes. Lake water for the reason it had objectionable odour, was suspected for being contaminated. An attempt was made to comprehend the potable competence lake waters of lake Sambhaji, at Solapur district (MS), India, by specifying total coliforms counts employing the method of Multiple Tube Test with double strength MacConkey Broth Medium (Himedia M539S), the traditional method for presumptive isolation of coliform bacteria by MPN, incubating at 370C for 24 hours, in addition to other tests. Most Probable Number (MPN) of total coliforms was determined by referring to standard probability table for estimation of total coliforms for the determination of MPN. The investigation of the cultural response revealed 480 cfu/ml at site 2 and 220 cfu/ml at site 1, exceeding limits for recreational water. The highest fraction of indicator coliforms was detected in the water sample at site 2, of lake Sambhaji which has truly objectionable odour as compared to site 1 of lake Sambhaji. Taking into consideration the observations of high coliform count at lake Sambhaji results portray a tragic testimony of the deterioration of the ecological health of the lake and advocates dismissal of the consideration of water for being thought for its potable potential, portraying human malady if exposed to such unsanitary lake. The results encompass imperative repercussion directing prioritization to design restoration strategies.

In the present study numerical analysis of enhancement in heat transfer characteristics in a double pipe heat exchanger is studied using a holed twisted tape. The twisted tape with a constant twist ratio is inserted in a double pipe heat exchanger. Holes of diameter 1mm, 3 mm and 5 mm were drilled at regular pitch throughout the length of the tape. Numerical modeling of a double pipe heat exchanger with the holed twisted tape was constructed considering hot fluid flowing in the inner pipe and cold fluid through the annulus. Simulation was done for varied mass flow rates of hot fluid in the turbulent condition keeping the mass flow rate of cold fluid being constant. Thermal properties like Outlet temperatures, Nusselt number overall heat transfer coefficient, heat transfer rate and pressure drop were determined for all the cases. Results indicated that normal twisted tape without holes performed better than the bare tube. In the tested range of mass flow rates the average Nusselt number and heat transfer rate were increased by 85% and 34% respectively. Performance of Twisted tape with holes was slightly reduced than the normal twisted tape and it deteriorated further for higher values hole diameter. Pressure drop was found to be higher for the holed twisted tape than the normal tape.

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.

This present paper explores the way in which the cellular manufacturing can help a selected manufacturing company for a selected Machining Center, a highly flexible shop with many different customers choice and products, achieve improved performance and customer satisfaction. The environment in which the product of selected company operates today is very different from the one in which it has historically succeeded. The decline in heavy commercial vehicle spending has increased the importance of cost or affordability in a decision process which previously emphasized the incorporation of state-of-the-art technology into new products in the heavy auto industry. In addition, the heavy vehicle industry consolidation is producing fewer companies competing fiercely for a piece of a decreasing pie. Therefore, Product of demand from master companies’ success depends on its ability to exceed customers’ expectations through superior performance, by delivering high quality products in a timely manner, with shorter lead-times and lower costs.

Thermal designing of a shell and tube heat exchanger typically includes the determination of heat transfer area ,number of tubes, tube length and tube diameter ,tube layout, number of shell and tube passes ,tube pitch, number of baffles, its type and size, shell and tube side pressure drop. This paper reveals the effects various parameters in the thermal designing of shell and tube heat exchanger.

Solar parabolic trough collectors are the most useful technology that directly supports renewable energy for conventional energy for water heating. But it is observed that due to ambient temperature many convective losses occur which effects the temperature variation. This article shows the practical work for increasing temperature to cover it by thin transparent glass plate which creates the oven effect and decreases its convective losses which increases the temperature and finally it increase its efficiency.