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This paper discussed the heat transfer enhancement due to groove formation in a metallic tube.A set of three tubes, namely, the simple metallic tube (SMT), the straight groove tube (SGT) and the helically grooved tube with 12-inch pitch (GT12) were numerically studied.The tube data and experimental findings on it were extracted from published article by Arunrat.Performance criteria through CFD was based on the heat transfer via Nusselt number as well as the friction factor.For the heat transfer performance, it was evaluated with the thermal performance factor given by (Nu/Nus)/(f/fs), whereas Nu is the Nusselt number and f is the friction factor and subscript 's' is for the smooth tube.Two turbulence models were used, viz, k-epsilon realizable and k-omega Shear Stress Transport.Between the two turbulence models tested and the given range of Reynolds number, it was found that k-ω SST is the most suitable candidate for this range of Reynolds number due to its closeness to the experimental data both in the case of the Nusselt and friction factor.Among the three tubes tested and making the simple metallic tube (SMT) the baseline, the GT12 performed better and has performance factor better than the other two at most of the Reynolds numbers.

Previous published works on the optimization of parameters in orthogonal cutting process have used a single tool. The parameters considered in these works are: surface roughness, power consumption, deformed chip shape, and temperature in the workpiece. This paper is on the optimization of machining parameters with multiple cutting tools. This is required to reduce the cutting forces and temperature while machining AISI 1045 steel. In this study, this has been achieved by using a combination of statistical tools including Taguchi matrix, signal to noise ratio, and analysis of variance (ANOVA). The effects of varying cutting speed, feed rate, depth of cut, and rake angle in orthogonal cutting process have been considered. The Finite Element (FE) simulations have been carried out with a general purpose commercial FE code, ABAQUS, and statistical calculations have been performed with Minitab. Results show that for optimum cutting forces, feed rate and depth of cut are the most important factors while for lower temperatures, cutting speed and rake angle play a significant role. It is concluded that carbide cutting tools is a better option as compared to uncoated cemented carbide cutting tool for machining AISI 1045 steel as it results in lower cutting forces and temperatures.