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In the present study, the thermal performance of a finned tube heat exchanger using aluminium oxide-deionized water nano-fluid has been evaluated. A counter flow type finned tube heat exchanger has been selected for experimentation. The volume concentration of aluminium oxide mixed with deionized water has been procured as 0.1, 0.2, 0.3, and 0.4% at a temperature range of 10-90°C. Stable nano-fluid dispersion is prepared with sodium dodecylbenzene sulphonate and sodium hexametaphosphate which is used as a stabilizer. The experiments are conducted with different flow volume for both hot and cold fluid ranging from 75-150 LPH. The thermal performance of heat exchange is found to have enhanced with the use of nano-fluid. The maximum LMTD has been found to be 25.70°C and 19.65°C with and without nano-fluid respectively. [ABSTRACT FROM AUTHOR]

A solar air heater is a system that transforms solar power into a form that may be used for a variety of heating applications. Researchers are experimenting to increase the heat transfer by breaking down the laminar sub-layer near the adsorbing plate. To break the laminar sub layer, researchers have applied varieties of roughness with different shapes and sizes. The experimentation with varieties of roughness leads to an increase in cost as well as effort. So, the development of high-end computational software can minimize this. Computational fluid dynamics has emerged as a very efficient tool to perform the analysis with less cost and effort. The paper aims to give a comprehensive review of CFD analysis that has been used by various researchers to evaluate the thermo-hydraulic performance of artificially roughened solar air heaters. This paper represents the brief details of the CDF model, CFD domain, different roughness, and system and operating parameters to achieve the optimal thermal performance of solar air heaters. [ABSTRACT FROM AUTHOR]

Tribology plays an important role in various metal cutting industries as it is mainly concerned with the quality of the products produced together with the life of cutting tools in use. With rise in temperature around the machining zone while cutting difficult-to-cut materials that can yield high residual stresses, dimensional deformation, and premature failure of cutting tools. Cutting fluid in this scenario plays an important role while being used as a coolant, lubricant to carry away the heat generated while minimizing the rate of tool wear thereby increasing its life and the quality of products produced. Selection of suitable cutting fluid for a specific machining operation is often influenced by several factors such as machine tool compatibility, interaction with operator, effect on environment, and efficiency which also requires in-depth knowledge of the operator. This paper explores the application potentiality of evaluation based on distance from average solution method for identifying the most appropriate cutting fluid for spur gears cutting using hobbing operation. The result obtained is observed to have high degree of similarity with the results obtained by other popular methods which are also validated from Spearman rank correlation. [ABSTRACT FROM AUTHOR]

The characteristics and performance of SAH can be drastically improved by providing artificial roughness on the absorber plate. Various protrusion and dimple with varied shapes, sizes and orientations has been studied. A thorough literature review on protrusions and dimples used as artificial roughness on the absorber plate has been presented in this paper. [ABSTRACT FROM AUTHOR]

This paper represents the experimental investigation on effects of various parameters that influences the vortex initiation height during the tundish draining in continuous casting process. Formation of vortex during draining plays a vital role to decide the quality of the steel because the formed vortex causes entrainment of slag into the molten steel during its flow into each casting strands. So, the vortex formation phenomenon needs to be study to avoid slag entrainment and also optimize the flow of molten steel into the mould. A Ladle-Tundish physical model is set up where; water acts as molten steel and paraffin oil as a slag. The slag entrainment process is observed visually. The experimental results show that the vortex initiation height predominantly depends on two factors that are slag thickness, and the volume outflow rate from tundish. [ABSTRACT FROM AUTHOR]

Milling is a conventional machining operation that uses a rotary cutter to remove material from the workpiece with the intention of generating different shapes. Slab milling is a type of milling operation which is used to machine workpiece with flat and wide surface. In this work, slab milling is performed on cast iron specimen to investigate the machining performance on various performance measures such as surface roughness, material removal rate along with low vibration. For design of experiments, Taguchi L25 orthogonal array is selected considering rotating speed, feed rate and depth of cut as the process parameters. Also to obtain the optimal cutting parameters which results in high surface finish and material removal rate along with low vibration, grey relational analysis aided with fuzzy logic is applied. For grey input coefficients five membership functions are considered, while nine membership functions are considered for output grey-fuzzy reasoning (GFRG) grade. In total twenty-five rules were generated using these membership functions and the optimal values of process parameters were found. Also, analysis of variance (ANOVA) is adopted to identify the significance of each input parameter on the machining performance. It was found that rotating speed has maximum the influence in determination of GFRG values. The optimal parametric combination is then verified with an experimental test run which shows significant improvement in the output responses. [ABSTRACT FROM AUTHOR]