Sateesh Yadav - Academia.edu (original) (raw)

Papers by Sateesh Yadav

Advances in Energy Research, Vol. 1, 2020

In this work, a numerical study is performed to analyze the reaction kinetics and associated tran... more In this work, a numerical study is performed to analyze the reaction kinetics and associated transport phenomena pertaining to the dissociation mechanism of salt hydrates (Epsom salt [MgSO4·7H2O]). During the dissociation process, the salt hydrate dissociates into a lower hydrate or an anhydrate and evolves water vapor. The chemical energy used for the process of dissociation gets stored in the lower hydrate or anhydrate in the form of bond formation internal energy. This energy can be recovered back either by passing water vapor through it or by extracting a heat flux, thus converting the stored chemical energy into sensible heat. For this, a macroscopic model of decomposition of salt hydrate has been presented by taking into account solid-state chemical kinetics, thermodynamics and associated transport phenomenon. Equations of chemical rate, mass and energy have been coupled employing a single domain continuum formulation and have been solved numerically for the process of diffusion. Subsequently, the influence of reaction kinetics on the heat storage and heat transfer behavior is described. Further, an energy analysis during the dissociation process is delineated. The model is able to predict temperature and concentrations of all the attendant species during the thermochemical dissociation reaction. The insights from the current study can develop a deeper understanding of the decomposition process and can be useful in designing thermal energy storage (TES) systems using salt hydrates.

Microcasting facilitates the fabrication of small structures in the micrometer range or of bigger... more Microcasting facilitates the fabrication of small structures in the micrometer range or of bigger parts carrying microstructures with high aspect ratio by means of solidifying molten metal in the microstructured mould. Microcasting can manufacture very complex structures and is scalable and economically efficient for mass production. In this paper, a numerical study of the mould filling in a microcasting process is presented. The microcasting mould cavity contains micro-sized channels. The free surface tracking method − Volume of Fluid (VOF)-based algorithm is used for predicting the free surface flows and tracking the metal–air interface during the filling process. The model is demonstrated for the case of filling of pure metal (aluminium) in the mould cavity, and the resulting evolution of the position of molten liquid interface in the microcasting part is presented. The level of molten metal in the micro channel fluctuates because of the variation of the pressure. The capillary a...

Journal of Energy Storage, 2020

For describing the thermochemical energy storage in salt hydrates, a model for dissociation of a ... more For describing the thermochemical energy storage in salt hydrates, a model for dissociation of a salt hydrate is presented in this work. The model comprehensively integrates the attendant transport phenomena of the dissociation process, reaction kinetics and convection of the generated vapor. Local salt hydrate particle size and permeability variation in the system resulting from the dissociation reaction, heat transfer and flow of vapor in the evolving porous medium are accounted. The coupled governing equations of chemical reaction rate, mass, momentum and energy are solved by a finite volume-based numerical method. The model is validated with the benchmark numerical result available in literature. Using the model the thermochemical dissociation of epsom salt in a thermal storage system is simulated. The transient evolution of temperature, concentration and flow fields during the dissociation reaction is described. System's performance is quantified with the help of performance indicators such as sensible, chemical, total energy and effectiveness. For the first time, the role of vapor flow on the physical behavior of the thermochemical energy storage system is delineated. It is observed that the flow of water vapor significantly influences system's temperature distribution which in turn influences all other physical aspects, such as local and global heat transfer, reaction progression, concentration field and storage performance of the system.

Applied Thermal Engineering, 2019

Intermittent ice slurry generation is an innovative and realistic solution for obtaining on-deman... more Intermittent ice slurry generation is an innovative and realistic solution for obtaining on-demand ice slurry. In this article, solidification and multiphase transport phenomena during ice slurry generation in an intermittent ice slurry generator is numerically investigated. The numerical model considers multiphase convection, sedimentation and remelting of ice particles, drag on ice particles, permeability variation across the mushy zone, and slurry viscosity as a function of ice fraction. Prior to discussing the results of intermittent generator, ice slurry generation is analyzed in a cylindrical ice slurry generator (without any intermittency) in order to better understand the attendant transport phenomena. The evolution of ice fraction, temperature and concentration fields, and solid-liquid drift velocity is described. Thermal performance analysis is carried out to optimize the operational and design parameters. In the context of the present study, the optimum generation of ice slurry takes place for 0.75 aspect ratio (H:D), 0.1527 Stefan number and 24% depressant concentration. Using these optimized parameters, simulations are performed for intermittent ice slurry generator. The evolution of ice fraction in each cycle of intermittent ice slurry generation is described. For each cycle, the maximum extractable amount of ice slurry, the cold energy available and the effectiveness of the system are delineated. It is observed that in successive cycles, the total cold energy available in the system increases. On the other hand, the cold energy available from the ice slurry zone decreases because of widening of the immobile mushy zone.

International Journal of Refrigeration, 2018

This study reports an analysis of isothermal and non-isothermal (with melting) ice slurry flow in... more This study reports an analysis of isothermal and non-isothermal (with melting) ice slurry flow in horizontal elliptical pipes. A three dimensional Euler-Euler granular multiphase turbulent CFD model has been constructed accounting the effects of particle collisions, drag, lift and turbulence dispersion. The model is applied to study isothermal and non-isothermal ice slurry flow in horizontal elliptical pipes and the characteristics, such as stratified flow development, heterogeneity in ice fraction distribution, pressure drop, melting and heat transfer are described. Isothermal ice slurry flow in elliptical pipes results in slightly lower heterogeneity as compared to circular pipes for a given constant flow rate. The heterogeneity of ice fraction distribution in the elliptical pipe increases as the size of the ice particles increase. For non-isothermal ice slurry flow, as compared to circular pipe elliptical pipe results in less melting tendency of ice particles.

Energy Procedia, 2016

Inorganic salt hydrates are promising candidates as latent heat storage materials entailing, for ... more Inorganic salt hydrates are promising candidates as latent heat storage materials entailing, for example, a high thermal energy storage density and cheap price [1,2] in spite that they have many handicaps. For almost all applications, Phase change materials (PCMs) have to be encapsulated, that is, they have to be hermetically sealed within barrier containments, preferably within small microcapsules. Encapsulation improves heat transfer, cycling stability, and material compatibility with the environment. However, no attempt has been completely successful to microencapsulate salt hydrates so far due to the high surface polarities of these substances, edge alignment effects, their tendency to alter their water content [3]. This work is aimed to encapsulate some commonly used salt hydrates; sodium sulphate decahydrate (Na 2 SO 4 .10H 2 O) and calcium chloride hexahydrate (CaCl 2 .6H 2 O) in a hydrophilic polymer; polyvinyl alcohol (PVA) stably for passive thermal energy storage systems. So that an economically beneficial application mean will be validated.

Topics in Mining, Metallurgy and Materials Engineering, 2015

Most of the studies reported for droplet impact and spreading on a substrate in a thermal spray c... more Most of the studies reported for droplet impact and spreading on a substrate in a thermal spray coating process assume that droplet solidifies as a pure substance, i.e., phase change occurs at a fixed temperature. The alloy type behaviour of the droplet impact where it solidifies within liquidus and solidus temperature is not well reported. The role of formation of mushy zone and species composition variation during the coating layer formation while using a multi-constituent alloy material is not known. This work investigates the impact, spreading and solidification characteristics of an alloy droplet impacting on a substrate. Two dimensional axisymetric model has been used to simulate the transient flow and alloy solidification dynamics during the droplet impingement process. Volume of fluid (VOF) surface tracking method coupled with the alloy solidification model within a one-domain continuum formulation is developed to describe the transport phenomena during the droplet impact, spreading and solidification of an alloy droplet on a flat substrate. Using the model the characteristics of alloy solidification in coating formation are highlighted.

Advances in Energy Research, Vol. 1, 2020

In this work, a numerical study is performed to analyze the reaction kinetics and associated tran... more In this work, a numerical study is performed to analyze the reaction kinetics and associated transport phenomena pertaining to the dissociation mechanism of salt hydrates (Epsom salt [MgSO4·7H2O]). During the dissociation process, the salt hydrate dissociates into a lower hydrate or an anhydrate and evolves water vapor. The chemical energy used for the process of dissociation gets stored in the lower hydrate or anhydrate in the form of bond formation internal energy. This energy can be recovered back either by passing water vapor through it or by extracting a heat flux, thus converting the stored chemical energy into sensible heat. For this, a macroscopic model of decomposition of salt hydrate has been presented by taking into account solid-state chemical kinetics, thermodynamics and associated transport phenomenon. Equations of chemical rate, mass and energy have been coupled employing a single domain continuum formulation and have been solved numerically for the process of diffusion. Subsequently, the influence of reaction kinetics on the heat storage and heat transfer behavior is described. Further, an energy analysis during the dissociation process is delineated. The model is able to predict temperature and concentrations of all the attendant species during the thermochemical dissociation reaction. The insights from the current study can develop a deeper understanding of the decomposition process and can be useful in designing thermal energy storage (TES) systems using salt hydrates.

Microcasting facilitates the fabrication of small structures in the micrometer range or of bigger... more Microcasting facilitates the fabrication of small structures in the micrometer range or of bigger parts carrying microstructures with high aspect ratio by means of solidifying molten metal in the microstructured mould. Microcasting can manufacture very complex structures and is scalable and economically efficient for mass production. In this paper, a numerical study of the mould filling in a microcasting process is presented. The microcasting mould cavity contains micro-sized channels. The free surface tracking method − Volume of Fluid (VOF)-based algorithm is used for predicting the free surface flows and tracking the metal–air interface during the filling process. The model is demonstrated for the case of filling of pure metal (aluminium) in the mould cavity, and the resulting evolution of the position of molten liquid interface in the microcasting part is presented. The level of molten metal in the micro channel fluctuates because of the variation of the pressure. The capillary a...

Journal of Energy Storage, 2020

For describing the thermochemical energy storage in salt hydrates, a model for dissociation of a ... more For describing the thermochemical energy storage in salt hydrates, a model for dissociation of a salt hydrate is presented in this work. The model comprehensively integrates the attendant transport phenomena of the dissociation process, reaction kinetics and convection of the generated vapor. Local salt hydrate particle size and permeability variation in the system resulting from the dissociation reaction, heat transfer and flow of vapor in the evolving porous medium are accounted. The coupled governing equations of chemical reaction rate, mass, momentum and energy are solved by a finite volume-based numerical method. The model is validated with the benchmark numerical result available in literature. Using the model the thermochemical dissociation of epsom salt in a thermal storage system is simulated. The transient evolution of temperature, concentration and flow fields during the dissociation reaction is described. System's performance is quantified with the help of performance indicators such as sensible, chemical, total energy and effectiveness. For the first time, the role of vapor flow on the physical behavior of the thermochemical energy storage system is delineated. It is observed that the flow of water vapor significantly influences system's temperature distribution which in turn influences all other physical aspects, such as local and global heat transfer, reaction progression, concentration field and storage performance of the system.

Applied Thermal Engineering, 2019

Intermittent ice slurry generation is an innovative and realistic solution for obtaining on-deman... more Intermittent ice slurry generation is an innovative and realistic solution for obtaining on-demand ice slurry. In this article, solidification and multiphase transport phenomena during ice slurry generation in an intermittent ice slurry generator is numerically investigated. The numerical model considers multiphase convection, sedimentation and remelting of ice particles, drag on ice particles, permeability variation across the mushy zone, and slurry viscosity as a function of ice fraction. Prior to discussing the results of intermittent generator, ice slurry generation is analyzed in a cylindrical ice slurry generator (without any intermittency) in order to better understand the attendant transport phenomena. The evolution of ice fraction, temperature and concentration fields, and solid-liquid drift velocity is described. Thermal performance analysis is carried out to optimize the operational and design parameters. In the context of the present study, the optimum generation of ice slurry takes place for 0.75 aspect ratio (H:D), 0.1527 Stefan number and 24% depressant concentration. Using these optimized parameters, simulations are performed for intermittent ice slurry generator. The evolution of ice fraction in each cycle of intermittent ice slurry generation is described. For each cycle, the maximum extractable amount of ice slurry, the cold energy available and the effectiveness of the system are delineated. It is observed that in successive cycles, the total cold energy available in the system increases. On the other hand, the cold energy available from the ice slurry zone decreases because of widening of the immobile mushy zone.

International Journal of Refrigeration, 2018

This study reports an analysis of isothermal and non-isothermal (with melting) ice slurry flow in... more This study reports an analysis of isothermal and non-isothermal (with melting) ice slurry flow in horizontal elliptical pipes. A three dimensional Euler-Euler granular multiphase turbulent CFD model has been constructed accounting the effects of particle collisions, drag, lift and turbulence dispersion. The model is applied to study isothermal and non-isothermal ice slurry flow in horizontal elliptical pipes and the characteristics, such as stratified flow development, heterogeneity in ice fraction distribution, pressure drop, melting and heat transfer are described. Isothermal ice slurry flow in elliptical pipes results in slightly lower heterogeneity as compared to circular pipes for a given constant flow rate. The heterogeneity of ice fraction distribution in the elliptical pipe increases as the size of the ice particles increase. For non-isothermal ice slurry flow, as compared to circular pipe elliptical pipe results in less melting tendency of ice particles.

Energy Procedia, 2016

Inorganic salt hydrates are promising candidates as latent heat storage materials entailing, for ... more Inorganic salt hydrates are promising candidates as latent heat storage materials entailing, for example, a high thermal energy storage density and cheap price [1,2] in spite that they have many handicaps. For almost all applications, Phase change materials (PCMs) have to be encapsulated, that is, they have to be hermetically sealed within barrier containments, preferably within small microcapsules. Encapsulation improves heat transfer, cycling stability, and material compatibility with the environment. However, no attempt has been completely successful to microencapsulate salt hydrates so far due to the high surface polarities of these substances, edge alignment effects, their tendency to alter their water content [3]. This work is aimed to encapsulate some commonly used salt hydrates; sodium sulphate decahydrate (Na 2 SO 4 .10H 2 O) and calcium chloride hexahydrate (CaCl 2 .6H 2 O) in a hydrophilic polymer; polyvinyl alcohol (PVA) stably for passive thermal energy storage systems. So that an economically beneficial application mean will be validated.

Topics in Mining, Metallurgy and Materials Engineering, 2015

Most of the studies reported for droplet impact and spreading on a substrate in a thermal spray c... more Most of the studies reported for droplet impact and spreading on a substrate in a thermal spray coating process assume that droplet solidifies as a pure substance, i.e., phase change occurs at a fixed temperature. The alloy type behaviour of the droplet impact where it solidifies within liquidus and solidus temperature is not well reported. The role of formation of mushy zone and species composition variation during the coating layer formation while using a multi-constituent alloy material is not known. This work investigates the impact, spreading and solidification characteristics of an alloy droplet impacting on a substrate. Two dimensional axisymetric model has been used to simulate the transient flow and alloy solidification dynamics during the droplet impingement process. Volume of fluid (VOF) surface tracking method coupled with the alloy solidification model within a one-domain continuum formulation is developed to describe the transport phenomena during the droplet impact, spreading and solidification of an alloy droplet on a flat substrate. Using the model the characteristics of alloy solidification in coating formation are highlighted.