Journal Articles
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/19884
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Item A review of lattice boltzmann method computational domains for micro-and nanoregime applications(Begell House Inc., 2020) Narendran, G.; Arumuga Perumal, A.P.; Gnanasekaran, N.In the last two decades, microscale and nanoscale devices have received much interest due to the inevitable performance and their numerous applications not only in the field of fluid flow and heat transfer but also in bio-technology, bio-medical engineering, etc. In many situations, besides the conventional experiments and theoretical analysis, computations have emerged as a valuable tool for investigating the fluid transport and heat transfer phenomena. The lattice Boltzmann method (LBM) has emerged as an important option for micro-and nanoscale devices due to the fact that the LBM is well established for the range of Knudsen number. A comparative study on several working fluids used in the field of micro-and nanodevices such as microchannel, micro-cavity, microboiling, and nanochannel is categorized. Various aspects of nanofluids used in natural convection with different cavity configurations, flow boiling, immiscible fluids, liquid–vapor phase change are also critically reviewed. Different remarks and findings of available numerical results with several investigated parameters were summarized. © 2020 Begell House, Inc.Item Thermodynamic irreversibility and conjugate effects of integrated microchannel cooling device using TiO2 nanofluid(Springer, 2020) Narendran, G.; Gnanasekaran, N.; Arumuga Perumal, A.P.Thermal management is highly essential for the latest electronic devices to effectively dissipate heat in a densely packed environment. Usually, these high power devices are cooled by integrating micro scale cooling systems. Most of the works reported in the literature majorly concentrate on microchannel heat sink in which the characteristics of friction factor and enhancement of heat transfer are analyzed in detail. However, due to the advent of compact electronic devices a crucial investigation is required to facilitate an amicable environment for the neighboring components so as to improve the reliability of the electronic devices. Henceforth, in the present study a combined experimental and numerical analysis is performed to provide an insight to determine the performance of a copper microchannel integrated with aluminium block using TiO2 nanofluid for different particle configurations. Needless to say, the present study, which also focuses on entropy generation usually attributed to the thermodynamic irreversibility, is very much significant to design an optimum operating condition for better reliability and performance of the cooling devices. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.Item Numerical and experimental analysis on thermal energy storage of polyethylene/functionalized graphene composite phase change materials(Elsevier Ltd, 2020) Chavan, S.; Gumtapure, V.; Arumuga Perumal, A.P.The main driving force behind the present work is environmental issues caused due to the usage of plastics, and energy issues. Current work attempts to address these problems by converting recycled plastics into thermal storage materials (TSM). Unfavorable thermophysical properties of plastic make it impractical but these inadequacies can be amended by blending with additives of superior thermophysical properties like, functionalized graphene. Numerical and experimental analysis are carried out to assess the thermal performance of TSMs (LLDPE, CPCM-1, CPCM-2 and CPCM-3) and check the compatibility of the materials. The phase change temperature of TSM is 123 to 125 °C and heat of fusion is 71.95 to 97 kJ/kg. Several thermal characteristics are analyzed to assess thermal performance and the amount of heat energy supplied, rate of heat transfer, and heat storage efficiency are deliberated. Results shown energy level enhancement of 43.17, 50.42, 54 and 50.61% for LLDPE, CPCM-1, CPCM-2 and CPCM-3 respectively. Among the TSM CPCM-2 shows relatively better storage capability (54% enhancement) due to incorporation of optimum concentration of enhancing material. The solidification process takes place through convection and radiation mode of heat transfer, at the completion of solidification process the TSM energy content reduces to 97.5, 96, 96 and 96% for LLDPE, CPCM-1,CPCM-2 and CPCM-3 respectively. This work concludes that, recycled plastics can be blended and it can be converted into efficient thermal storage material. © 2019 Elsevier LtdItem EFFECTS OF NANOREFRIGERANTS FOR REFRIGERATION SYSTEM: A REVIEW(Begell House Inc., 2023) Kumar, A.; Narendran, G.; Arumuga Perumal, A.P.In this article various nanorefrigerants have been critically reviewed towards the performance enhancement of the refrigeration system. Research has been more focused on the different techniques to prepare nanorefrigerants. This paper is an attempt to summarize all aspects of nanorefrigerants such as preparation, thermophysical properties, hydrodynamic study, boiling heat transfer, and performance of nanorefrigerants. It also discusses the effects of different nanoparticles on ther-mophysical properties. Nanorefrigerants are a special category of nanofluid, advanced nanotech-nology-based refrigerants that are stable mixtures of nanoparticles and base fluid, which improve thermophysical properties such as heat transfer and pressure drop and bring compactness to the system. This article presents an overview of improving thermal performance by using different nanoparticle blends with different base refrigerants. Further, influential parameters of nanopar-ticles and thermal performance are discussed. This paper also discusses the effects of different nanoparticles such as Al2O3, TiO2, CuO, carbon nanotubes (CNTs), etc., on thermophysical prop-erties. The present situation requires a robust system and refrigerants for required performance. Some refrigerants cannot be used directly. So, this paper deals with using nanorefrigerants for better system performance such as coefficient of performance (COP) enhancement, compressor work reduction, and energy efficiency. It is seen that the use of nanorefrigerants, or nanotechnology-based refrigerants, results in highly effective cooling and thus enhances the thermophysical properties of refrigeration systems. © 2023 by Begell House, Inc. www.begellhouse.com.Item Analysis of Fluid Flows in Bounded Domain with Particular Shape of a Cavity using Lattice Boltzmann Method(Bentham Science Publishers, 2023) Shetty, V.V.; Balashanker, K.; Arumuga Perumal, A.P.; Patel, V.U.The present work numerically models the incompressible, continuous phase, viscous flow of Newtonian fluid flow in a bounded domain of two-dimensional cavity that is driven by walls and contains grooves in the shape of squares on the lower wall. With the help of the mesoscopic lattice Boltzmann method (LBM) and D2Q9 square lattice model, simulation results are found stable and reliable. The flow physics of the problem by varying Reynolds number, the height and quantity of lower wall grooves, and other fluid flow characteristics within the bounded domain are studied in detail. It is seen that the effects of the groove heights and wavelengths on the fluid flow are structured within the bounded domain. The study is performed from low Re = 100 to high Re = 3200, with minimum two and maximum four-wavelength grooves evaluated on the bottom surface, each having a height of low 0.25 and high 0.75. Additionally, a thorough discussion of complicated vortex dynamics is provided regarding the input parameters and geometry. Objective: The current study aims to use mesoscopic LBM to analyze incompressible viscous fluid flows on complex geometries other than rectangular shapes. Methods: Mesoscopic approach of kinetic theory-based Lattice Boltzmann method (LBM) is implemented in the current work. The popular Single Relaxation Time Lattice Boltzmann method with D2Q9 square lattice model and second-order accurate boundary condition is adopted for the current study. Results: The numerical approach of LBM is used to simulate fluid flows in a 2D bounded domain with grooved bottom surfaces. The influence of different factors, such as the height of bottom-wall surface grooves, flow Reynolds number, and wavelength of these grooves on flow patterns, is then investigated. Conclusion: The numerical study of the bounded domain is considered, and the Reynolds number is varied from 100 to 3200, with two and four-wavelength grooves evaluated on the bottom surface, each having a height of 0.25 and 0.75. The impacts on the flow pattern both within and slightly above the grooves of the computational findings for different Reynolds numbers, groove heights, and groove wavelengths are evaluated. As the Reynolds number rises, the mixing phenomenon of fluid is shown to flow more quickly in the wall-driven enclosures. © 2023 Bentham Science Publishers.