Mechanical Deparment

Energy harvesters that extract energy from vibrating system with the help of piezoelectric cantilever beam show strong potential for powering wireless devices. This paper presents numerical characterization of piezoelectric cantilever beam having rectangular cross-section to enhance the power of energy harvesters. The beam was modeled based upon Euler Bernoulli's beam theory. In this work, piezoelectric cantilever beam with 31 effects was developed to analyze the dynamic behavior of this system with the help of finite element method. It was noticed that the highest tip displacement of cantilever beam was in the second mode at 25 mm length. It was further indicated that second mode of resonant frequency provided higher voltage as compared to first mode of cantilever beam without any proof mass. But when proof mass was added at free end the voltage dropped in the second mode and increased in first mode under a proof mass of 0.40 g.

This research work investigates the energy absorption, and damage tolerance behavior of three phased (carbon woven/epoxy/ multiwall carbon nanotubes) polymer composites. Five doping weight fractions of multi-wall carbon nanotubes (MWCNTs) are considered as 0, 1, 2, 3 and 4 wt.% of thermosetting epoxy resins. Low-velocity impact (LVI) tests are conducted on drop tower setup with three different velocities, 3.5, 4.5 and 5.5 m/s. Damage caused by a 10 kg, hemispherical headed cylindrical impactor is analyzed and compared. The experimental results showed an increase in the energy absorption up to 3 wt.% of the MWCNT doping. However, reinforcing above this percentage, the energy absorption is reduced due to the formation of MWCNT agglomerations. Therefore, this work proposed an optimized doping percentage for CFRP laminates. The maximum improvement of 51.83% in energy absorption was found at 3 wt.% of MWCNT reinforcement in epoxy resins.

In this research work, the effect of Xenon poisoning in a Canadian Deuterium Uranium (CANDU) reactor for different load cycles has been examined. The three load cycles that have been analyzed are 100%-70% full power, 100%-60% Full Power (FP), and 100%-50% FP. It is considered that the CANDU reactor has operated for a full week on a particular load cycle and the maximum excess of Xenon reactivity that accumulated in the reactor during the load cycle has been estimated. After calculating the excess Xenon reactivity in a load cycle, it has been analyzed whether it is within given reactivity limit (-18 to +7 mk) provided by devices which include liquid zone controllers, absorbers and adjusters in a CANDU reactor. Further it has been also mentioned as to what are options of controlling the reactor power if this excess reactivity exceeds the limit supplied by adjusters, absorbers and liquid zone controllers. With the results of the mathematical analysis of Xenon and Iodine concentration the optimized load cycle on which the CANDU reactor should be operated has been estimated. The impact of all the three power cycles on the uranium fuel is also studied.

During LVI in fiber/epoxy composites, the dominant damage mechanisms are: matrix cracking (crack generation), delaminating (interface failure) and fiber fracture [18]. Matrix modification using MWCNTs provides better load transfer [19] and improved

Present work deals with the numerical investigation of a cantilever beam having I cross section made up of piezoelectric material for its actuation capability. The beam is modeled under the assumption of Euler's Bernoulli equation. Eight cases are considered for different electrode locations. The beam was subjected to voltage loads at different locations. It was noticed that tip deflection increases with increasing applied voltage across the electrodes. Maximum tip deflection was achieved with the increase in voltage with particular electrode arrangement. In this report we have also demonstrated that for downward tip deflection, there are two values of thickness ratio of flange and web for a given tip deflection at a given applied voltage.

Digital Twin-based Cyber-Physical Quality System (DT-CPQS) concept involves automated quality checking, simulation, and prediction of manufacturing operations to improve production efficiency and flexibility as part of Industrie4.0 initiatives. DT-CPQS will provide the basis for the manufacturing process to march towards an autonomous quality platform for zero defect manufacturing in the future. Analysing sensor data from the CNC machine and vision monitoring system it was concluded that there was enough signal data to detect quality issues in a part being machined in advance using statistical/mathematical models (Smart PLS) and using machine learning algorithms. This allows the operator to take corrective actions before the resultant part ends in a quality failure and reduces the inspection time. The proposed approach forms the basis in expanding this concept to a large machine shop wherein by monitoring various parameters of the machines and state variables of the tools we can detect quality issues and develop an automated quality system using machine learning techniques.

In this paper, we propose a Cyber-Physical Quality System (CPQS) integrated framework that can predict, analyze, and
validate the quality monitoring system in manufacturing with 95% accuracy in real-time using machine learning techniques.
CPQS framework analyses real-time sensor networks and configures the importance of artificial intelligence-driven big data
analytics for predicting the quality of cyber-physical production networks. Cyber-physical data like speed, feed, depth of cut,
coolant temperature, vibrations, tangential cutting forces, and tool life for 400 parts were collected from the various sensors placed on Computerized Numerical CNC) machines after doing modal analysis.  Various machine learning techniques were used to predict the quality of the part wherein the inputs affecting it were predominately dominated by
vibration and temperature. Extreme Gradient Boosting (XGB) machine learning techniques out of many could predict the quality of the part with
96.2%. accuracy. The caveat for the present results is that it has been tried out only for Titanium Alloy parts and the tool wear has been approximated using Taylor’s equation which can be enhanced by using image processing. The model deployed in real-time could produce defect-free parts quickly. This could reduce the cost of quality by 80%, thereby increasing the production line's productivity, quality, and efficiency.

Digital Twin-based Cyber-Physical Quality System (DT-CPQS) concept involves automated quality checking, simulation, and prediction of manufacturing operations to improve production efficiency and flexibility as part of Industrie4.0 initiatives. DT-CPQS will provide the basis for the manufacturing process to march towards an autonomous quality platform for zero defect manufacturing in the future. Analysing sensor data from the CNC machine and vision monitoring system it was concluded that there was enough signal data to detect quality issues in a part being machined in advance using statistical/mathematical models (Smart PLS) and using machine learning algorithms. This allows the operator to take corrective actions before the resultant part ends in a quality failure and reduces the inspection time. The proposed approach forms the basis in expanding this concept to a large machine shop wherein by monitoring various parameters of the machines and state variables of the tools we can detect quality issues and develop an automated quality system using machine learning techniques.

Article History: Received: 10 November 2020; Revised: 12 January 2021; Accepted: 27 January 2021; Published online: 05 April 2021 Abstract: Digital Twin-based Cyber-Physical Quality System (DT-CPQS) concept involves automated quality checking, simulation, and prediction of manufacturing operations to improve production efficiency and flexibility as part of Industrie4.0 initiatives. DT-CPQS will provide the basis for the manufacturing process to march towards an autonomous quality platform for zero defect manufacturing in the future. Analysing sensor data from the CNC machine and vision monitoring system it was concluded that there was enough signal data to detect quality issues in a part being machined in advance using statistical/mathematical models (Smart PLS) and using machine learning algorithms. This allows the operator to take corrective actions before the resultant part ends in a quality failure and reduces the inspection time. The proposed approach forms the basis in expandi...

In this study, both model analysis and electrical characterization of a dielectric barrier discharge based argon plasma jet have been carried at atmospheric pressure in a pin electrode configuration. The plasma and fluid dynamics modules of COMSOL multi-physics code have been used for the modeling of the plasma jet. The plasma parameters, such as, electron density, electron temperature and electrical potential have been analyzed with respect to the electrical parameters, i.e., supply voltage and supply frequency with and without the flow of gas. In all the experiments, gas flow rate has been kept constant at 1 liter per minute. This electrode configuration is subjected to a range of supply frequencies (10-25 kHz) and supply voltages (3.5-6.5 kV). The power consumed by the device has been estimated at different applied combinations (supply voltage & frequency) for optimum power consumption at maximum jet length. The maximum power consumed by the device in this configuration for maximum jet length of ∼26 mm is just ∼1 W.

In this paper, a dielectric barrier discharge plasma based atmospheric pressure plasma jet has been generated in a floating helix and floating end ring electrode configuration using mixture of argon and nitrogen gases (50:50 ratio). This configuration is subjected to a range of supply frequencies (10–25 kHz) and supply voltages (6.5–9.5 kV) at a fixed rate of gas flow rate (i.e., 1 l/min). The electrical characterization of the plasma jet has been carried out using a high voltage probe and current transformer. The current–voltage characteristics have been analyzed, and the power consumed by the device has been estimated at different applied combinations of supply frequency and voltages for optimum power consumption and maximum jet length. A comparative analysis of the results of the above experiments has shown that maximum power consumed by the device in helix electrode configuration with end ring is 19 W for (Ar+N2) mixture as compared to only 12 mW and 7.7 mW for Ar and He gas res...

Power generation in a nuclear plant is dependent on the Nuclear steam supply system (thermal energy source), the turbine generator (energy conversion), the circulating water system (heat rejection) and condensate/feed water system (regenerative heat and recycle of working fluid) and the plant electric system supporting these. These power generation processes must be operated so as to maintain energy and mass balance under changing conditions of load and environment. Grid electrical disturbances cause significant deviations in grid supply voltage and frequency. The abnormal conditions that accompany the imposition of grid electrical disturbances on a nuclear plant can disrupt the dynamic state of process systems equilibrium. The impact of grid electrical disturbances are in two different ways viz. (i) process degradation and (ii) impact on electrical components. Analysis of both these aspects are required to be carried out to design efficient reactor system high plant availability. I...

Abstract- Power generation in a nuclear plant is dependent on the Nuclear steam supply system (thermal energy source), the turbine generator (energy conversion), the circulating water system (heat rejection) and condensate/feed water system (regenerative heat and recycle of working fluid) and the plant electric system supporting these. These power generation processes must be operated so as to maintain energy and mass balance under changing conditions of load and environment. Grid electrical disturbances cause significant deviations in grid supply voltage and frequency. The abnormal conditions that accompany the imposition of grid electrical disturbances on a nuclear plant can disrupt the dynamic state of process systems equilibrium. The impact of grid electrical disturbances are in two different ways viz. (i) process degradation and (ii) impact on electrical components. Analysis of both these aspects are required to be carried out to design efficient reactor system high plant avail...

The need for a better cooling purpose in bio medical, electronics, microprocessors and radars has attracted many researchers. Since, microchannels fulfil this objective it's machining through different micro machining techniques requires more skill and knowledge. Micro electrical discharge machining (EDM)is considered as one of the advanced methods of machining micro tools, dies, channels, grooves etc. More emphasis should be given to this machining process so that complicated geometries with least effort can be produced. In the present work critical study has been done on different tool materials as well as workpiece materials used on machining work table in micro EDM with different new strategies of machining will be helpful to enhance understanding of the subject. Along with this a direct method of getting tools for making micro holes and grooves on workpiece is suggested. Keyword-Microchannel, tool electrode, microholes, microgrooves, material removal rate, tool wear I. INTRODUCTION In recent years micro-electro discharge machining(EDM) gained a significant role in fabrication of very complex microstructures like micro holes, channels, grooves and 3-D structures irrespective of the hardness of the workpiece material [1]. This technology helps to remove micro particles easily from electrically conductive materials due to generation of spark which associated with melting and vaporization of materials from the surface of workpiece [2].As it is a contactless process that exerts very small force on both electrode and specimen, it minimizes the chances to develop thermal stresses. The major difference between macro and micro electro discharge machining is well defined by the plasma size[3].µ wire EDM, µ-die sinking,µ-milling and drilling are the different varieties of micro EDM with respect to tool and tool kinetics[4].In micro wire EDM the electrode used is either tungsten or copper wire of diameter 25-300µm that cut through the specimen where as in micro die sinking EDM the tool electrode is the replica to be produced in workpiece[5]. To get a fine electrode, reverse polarity is done where material generally gets removed from electrode instead of workpiece. This process generally called as wire electro discharge grinding or WEDG. After getting desired shape of electrode by WEDG that can be used to drill small hole on workpiece called EDM drilling. In EDM milling cylindrical electrode is rotated which follow a path through the workpiece to produce required geometry. Micro EDM is the machining on EDM where sizes of the tool, discharge energy are in micro levels[6]. There are large research possibilities in this area as it has very wide applications[7]. Micromachining in EDM has been extensively studied by many researchers and presented in [8,9,10]. Sato et al [11] were the first to propose micro hole drill by EDM for ink-jet nozzles of printers.The holes produced are of diameter 15 to 300 µm. In addition to micromachining microelectrodes can be generated by wire electro discharge grinding (WEDG) [12,13].Tungsten electrodes with diameter 300µm were machined to form 200µm using WEDG to produce microstructures on single crystal P-type boron doped silicon as it is widely used in semiconductors [14]. Masuzawa et al [15] proposed a system for drilling microholes by EDM. Anew technology is developed where micro holes and shafts are produced of 5 µm in diameter [16].Different materials used as electrodes in EDM are of different shapes of copper,tungsten,graphite, silver and brass[17,18]. Mohite et al [19] developed a EDM tool for fabrication of leaf shape microchannel heat sink of Aluminium 6061 and optimize the process parameters by using orthogonal array Taguchi's analysis of variance (ANNOVA) and signal to noise ratio (S/N ratio).Yan et al [20] found fabrication of tool electrode for micro hole fabrication by die sinking EDM as the most difficult job. An experimental procedure is followed by them to get a small, fine and straight cupper tool electrode to make micro holes in carbide workpiece.Yu et al [21] modified commercial EDM machine to get planetary motion of tungsten electrode used as tool to produce high aspect ratio micro holes and blind non circular holes on stainless steel AISI 304L workpiece material and at the same time blind triangular, square,pentagonal micro holes are achieved by offsetting the tool path by 15 to 20 µm. Jahan et al [22]

A physical problem of laminar flow through a silicon-based rectangular microchannel with designed surface roughness was solved numerically. Different shapes of the surface roughness such as: triangular, semicircular and trapezoidal were placed along the channel wall. The two-dimensional problem was modelled and simulated in the FLUENT's computational fluid dynamics (FLUENT-CFD) environments. The working fluid taken was incompressible in nature hence the no-slip condition was assumed. The inlet condition was taken as constant velocity and at the outlet was considered as zero gauge pressure as boundary conditions. The total number of grids taken was 12,444 for the computational domain. FLUENT's segregated solver as an implicit solver was used. The effects of different working fluids such as: water, ethanol refrigerant and engine-oil on heat transfer were investigated for the same value of roughness pitch and height. The simulation results revealed that the Nusselt number variation along the channel was more for engine-oil than that for ethanol and water. This might be due to the fact that Nusselt number is a function of Prandtl number and the Prandtl number is comparatively high for engine oil.

Spray technology has numerous applications in general and cooling microchannels in particular. But before that study of the controlling parameters on which spray performance depends need to be explored. Present work describes an experimental study on microchannel cooling with jet and spray at different pressure combinations of air and water. The experimental facility was developed at the School of Mechanical Engineering, KIIT, deemed to be University, Bhubaneswar, to investigate the effect of various controlling parameters like fluid pressure, flow rate, nozzle to surface distance and heat input on jet and spray cooling of microchannels. The input parameters like air pressure and water pressure along with nozzle to surface distance were optimized. The input parametrs such as air and water pressure in the range of 1 bar to 3 bar, nozzle tip to surface distance in the range of 10 to 20 mm were considered during the tests. As a result, at 1 bar air pressure, 3 bar water pressure and 17.42 mm nozzle tip to surface distance, the maximum heat transfer coefficient was achieved as predicted optimal solution through response surface methodology (RSM). The data were compared with that of the earlier researcher's experimental work. The experimental results revealed that the employment of spray impingement cooling technique on microchannels provided significant improvement in removal of heat flux with less consumption of coolant.

The present article discusses the experimental results on heat transfer characteristics of spray impingement cooling of a stationary steel plate. The eexperimental setup consisted of an electrically heated flat stationary steel plate of dimension 120 mm x 120 mm x 4 mm, spray setup, water supply and air supply unit. The effects of various controlling parameters such as air-water pressures, water flow rate, nozzle tip to target distance and impingement density were determined and analysed. The cooling rates were computed from the time dependent temperature history and used to analyse the parametric effects. The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods available in the open literature. NOMENCLATURE ∆T Measured temperature difference ∆T * Non-dimensional temperature difference Tc Temperature of cooling water T Time t * Non-dimensional time l Length of t...

A new method, the rule of the mixture is developed for the determination of thermal conductivity (K), allied properties viz.density and the volume of the individual composite coating powders. Optimum coating thickness through steady-state thermal analysis of composite coating (Al2O3+ZrO2•5CaO) applied on cast iron surface is carried out. Also, the thermodynamic behaviour of TGO and bond coat were simulated .The thickness of the topcoat, TGO, and the bond coat was varied independently in the range of 0.1 to 0.04 mm. Results show that topcoat thickness doesn't have much influence on the heat transfer. However, TGO and the bond coat plays a crucial role in heat transfer study. Maximum heat resistance ,171.47 ºC observed at 1 mm TGO thickness, compared to 88.94 ºC in case of bond coat for the same coating thickness. It is also understood that 1 mm of optimal TGO thickness may be beneficial in the design of thermal barrier composite coating systems.