National Institute of Technology, Silchar

About: National Institute of Technology, Silchar is a education organization based out in Silchar, Assam, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 1934 authors who have published 4219 publications receiving 41149 citations. The organization is also known as: NIT Silchar.

Taguchi analysis of surface modification technique using W-Cu powder metallurgy sintered tools in EDM and characterization of the deposited layer

Abstract: The present study describes an experimental research on surface modification during electrical discharge machining (EDM) by depositing a hard layer over the work surface of C-40 grade plain carbon steel using specially prepared powder metallurgy compact tools The investigated process parameters were composition, compaction pressure, sintering temperature, pulse on-time, peak–current setting, and duty factor Measurements of deposited layer thickness, mass transfer rate, tool wear rate, surface roughness and microhardness were undertaken on the EDM-ed specimens Different studies like X-ray diffraction, optical microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy were carried out to ascertain the characteristics of the deposited layer on the work surface These analyses confirmed the presence of the tool materials in the work surface layer At first, an L-16 orthogonal array was applied as Taguchi DOE technique and the ANOVA was done to study the effects of pertinent process parameters An optimum condition was achieved using overall evaluation criteria Later on, a detailed study was carried out to get a smooth and regular deposition of material The characterization of the deposited layer is presented The deposited layer with a wide range of average layer thickness of 3–785 μm, enriched with tool materials (W and Cu) and with the formation of tungsten carbide, and having microhardness of 981–1275 GPa at the hardest zone was successfully deposited over the work surface

Numerical and experimental investigations on the performance of a serpentine microchannel with semicircular obstacles

Abstract: This paper focuses on computational and experimental analysis of a simple serpentine microchannel without obstacles and serpentine microchannel with semicircular obstacles of different sizes. The work has been performed in three phases- computational analysis, experimentation and flow physics study. The 3D models of a simple serpentine microchannel (without obstacles) and serpentine microchannels with semicircular obstacles (with radius as 50, 100, 150 and 200 µm) have been developed using COMSOL Multiphysics software. The effect of obstacle size on pressure drop and mixing length for achieving index 1 has been analyzed. A simple serpentine qmicrochannel and a serpentine microchannel with 150 µm radius semicircular obstacles have been fabricated with polydimethylsiloxane using soft lithography process. The experimental analysis for pressure drop as well as mixing index has been performed. A good agreement has been observed between experimental and computational results. The validated computational model is then used to study the mixing index for the same microchannels for different flow conditions, i.e. for different Reynolds numbers. The mixing lengths are observed to be lesser for Re 0.28 and 30. Further, the effect of diffusion and generation of secondary flow due to advection on mixing length for the considered Reynolds numbers are analyzed through the flow physics study.

Natural convection heat transfer and entropy generation inside porous quadrantal enclosure with nonisothermal heating at the bottom wall

Abstract: In this work, we study numerically the natural convection heat transfer and entropy generation characteristics inside a two-dimensional porous quadrantal enclosure heated nonuniformly from the bott...