Applied Mechanics and Materials Vols. 813-814

Abstract: Metal Matrix nanoComposites (MMNC) refer to materials consisting of a ductile metal or alloy matrix in which some nanosized reinforcement materials is implanted. These materials combine metal and ceramic features, i.e., ductility and toughness with high strength. Thus, metal matrix nanocomposites are suitable for production of materials with high strength in shear/compression processes and high service temperature capabilities. Both Metal Matrix Composite (MMC) and Ceramic Matrix Composites (CMC) with Carbon nanoTubes (CNT) nanocomposites hold promise, but also pose challenges for real success. In the present paper deals an inclusive review of literature in effect of nanoparticles in reinforced metal matrix composites on the machinability characteristics of the composite materials.

Abstract: Steel and its alloys have a wide range of applications in many industries like automobile, defense, architecture, chemical etc. In the present work, spring back analysis has done on three different grades of steel (SS202, SS309 and MS2016) sheet materials are considered. An experimental setup has been developed for spring back by the design and fabrication die. Spring back behavior is noted in all the three sheets in three rolling directions 0 ̊, 45 ̊ and 90 ̊. Results showed that spring back is noted in all the sheets with an angle of order 1-10 ̊.The load displacement behavior also seen for all the experiments.

Abstract: Swirling Fluidized Bed Polishing (SFBP) is a non–traditional alternative abrasive flow surface finishing form of Fluidized Bed Machining (FBM) in which the former has special features to overcome certain significant limitations of the latter, namely the variation of the surface roughness vertically along the component surface and the screening effect owing to the complex contours in the work piece geometry. Owing to its ability to perform machining and generate polished surface from a roughness value of Ra 1.2μ to 0.2 μ within 8 hours of processing, this new method offers greater scope in the surface modification of rough machined surfaces with complex geometry such as component with ducts and grooves. This research focus on investigating the effect of abrasive particle concentration on metal removal rate per unit area of the specimen surface. 3D surface morphology analysis investigates the quality of the polished surface and the study of circumferential uniformity and machining accuracy analysis on a complex-contoured component further investigate its scope and relevance in industrial applications.

Abstract: This manuscript introduces a class of higher order compact schemes for the solution of one dimensional (1-D) Euler equations of gas dynamics. These schemes are fourth order accurate in space and second or lower order accurate in time, depending on a weighted average parameter μ. The robustness and efficiency of our proposed schemes have been validated by applying them to three different shock-tube problems of gas dynamics, including the famous SOD shock-tube problem. Later on, the 1-D convergent-divergent nozzle problem (De laval nozzle problem) is also considered and numerical simulations are performed. In all the cases, our computed numerical solutions are found to be in excellent match with the exact solutions or available results in the existing literature. Overall the schemes are found to be efficient and accurate.

Abstract: A 3-Dimensional fluid flow over the sudden expansion region of a horizontal duct for various Reynolds numbers have been studied by using the CFD Software package ANSYS Workbench Fluent v 13.0. The expansion ratio and aspect ratio for the sudden expansion are taken as 2.5 and 4 respectively. This work deals with the finding of critical Reynolds number for a fluid and also the length of re-attachments on stepped walls at various Reynolds numbers for the same fluid. The simulation is carried out in sudden expansion for Reynolds number ranging from 200 to 4000. The variations of local Nusselt number along the stepped walls of the sudden expansion are presented with the heat flux of 35 W/m2 on the stepped walls. Also, the plots of pressure coefficient (Cp) along the stepped walls for different Reynolds numbers are presented in this work.

Abstract: The development of heat exchangers from two streams to multi-stream passage arrangement becomes a key problem for heat exchanger design. In this paper, a new design is developed for multi-stream (four-channel) heat exchanger. Multi-channel heat exchangers are extensively used in refrigeration and air conditioning, chemical industries, milk pasteurization, cryogenics industries and energy-recovery applications due to their higher heat transfer rates. The focus of this study is to determine the performance of four-channel counter flow heat exchanger. The hot and cold fluids are assumed to recirculate and exchange heat between them. Finite element model of the heat exchanger is developed based on the detailed geometry and the specific working conditions with the help of which effectiveness of the four-channel heat exchanger is computed. Non-Dimensional parameters are introduced which makes the analysis more versatile. The effectiveness is computed for different values of NTU and heat capacity ratio.

Abstract: Proliferation in the use of digital data in manufacturing led to a new industrial revolution by virtue of which user groups and researchers from multiple industrial enterprises have introduced Rapid Prototyping (RP) into their product development processes. This paper presents a coupled field thermos-structural analysis of new RP process namely, Selective Inhibition Sintering Process (SISP) for the evaluation on the effect of temperature in various polymer materials. The present study provides information of the requirement of heat source to achieve effective sintering phenomenon. The structured Finite Element (FE) model with a dimension of 30 X 30 X 1.5 mm is considered for the analysis where in different heat quantity is applied in an iterative manner to examine the sintering temperature. Based on the simulation results, for each polymer, required amount of heat to observe sintering characteristics is evaluated. The effect of applied heat on the examination of structural aspects of polymer materials including thermal stress, distortion and displacement is carried out. The simulation results affirms that the polymer materials are within in the safe structural and thermal limit and the selection of low cost heat source will be useful for the development of cost-effective SISP system.

Abstract: This paper presents an experimental study of natural convection V-grooved solar heater. Based on the experimental study, the first law and second law efficiencies and entropy generation have been calculated considering the available radiation under the meteorological conditions of Bhubaneswar, Odisha, India. Experiments were conducted during the month of November 2014 to March, 2015 for studying the performance characteristics of the solar air heater. The results obtained are quite significant with respect to outlet air temperature as compared to other solar heaters. The maximum air heater efficiency was found to be 16.91%, calculated at a mass flow rate of 3.55 gm/s of air and the second law efficiency was 6.72%.

Abstract: Microchannels are of current interest for use in heat exchangers, where very high heat transfer performance is desired. Microchannels provide very high heat transfer coefficients because of their small hydraulic diameters. In this study, a numerical investigation of fluid flow in microchannels with varying hydraulic diameters is presented. Six channels with wavy shape are considered. Header is the major part in the microchannel, which supplies fluid into different channels. A CFD model was created to simulate the fluid flow in the header and microchannels. In this work, five different shapes of the header were considered namely circular, frustum conical, rectangular, triangular and trapezoidal. The results from these simulations are presented, and it is observed that the flow distribution is significantly affected by geometrical properties of the channel and the header.

Abstract: In this paper, the influences of magnetic field and porous space of peristaltic flow of a Newtonian fluid in the tapered channel are studied. Flow analysis is also discussed in the presence of heat transfer. A model of wall-induced fluid flow within an infinite tapered channel having symmetric wall displacements and phase difference is developed. Expressions of dimensionless stream function and temperature are obtained analytically by employing long wavelength and low Reynolds number assumptions. The effects of various emerging parameters on the flow characteristics are shown and discussed with the help of graphs. It has been found that The geometric parameters likes, non-uniform parameter, amplitudes and phase difference control the fluid transport phenomena.