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Article
Publication date: 9 July 2024

Abhishek Sahu and Shubhankar Bhowmick

Transient response of continuous composite material (CCM) fin made of high thermally conductive composite material is presented. The continuously varying effective properties of…

43

Abstract

Purpose

Transient response of continuous composite material (CCM) fin made of high thermally conductive composite material is presented. The continuously varying effective properties of composite material such as thermal conductivity, heat capacity and density have been modelled using the Mori-Tanaka homogenization theory and rule of mixture. Additionally, temperature dependency of thermal conductivity, heat generation (composite materials) and convection coefficient (fluid properties) have also been incorporated. Different base boundary conditions are addressed such as oscillating heat flow, oscillating temperature, step-changing heat flow and step-changing temperature. At the other boundary, the fin is assumed to have a convective tip.

Design/methodology/approach

Lattice Boltzmann method is implemented using an in-house source code for obtaining the numerical solution of typical non-linear heat balance equation of the aforementioned problem under various transient base boundary conditions.

Findings

The effects of various thermal parameters such as material diffusivity ratio and conductivity ratio, area ratio and Biot number on transient response of fin and temperature distribution of fins are studied and interpreted. The heat transfer rate and time for attainment of steady state temperature of metal matrix composite (MMC) fin are found to be proportionally dependent on their diffusivity ratio. Additionally for higher values of area ratio and biot number, MMC fins are reported to dissipate the heat more efficiently in comparision to homogeneous fins in terms of time required to attain the steady state and surface temperature.

Practical implications

Response of transient fin associated with advanced class of material can facilitates the practicing engineers for designing high-performance and/or miniaturized thermal management devices as used in electronic packaging industries.

Originality/value

Studies of composite fin consisting of laminating second layer of material over the first layer have been reported previously, however transient response of CCM fin fabricated by continuously varying the volume fraction of two materials along the fin length has not been reported till date. Such material finds its application in thermal management and electronic packaging industries. Results are plotted in form of a graph for different application-wise material combinations that have not been reported earlier, and it can be treated as design data.

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Article
Publication date: 7 June 2021

Royal Madan and Shubhankar Bhowmick

The purpose of this study is to investigate Thermo-mechanical limit elastic speed analysis of functionally graded (FG) rotating disks with the temperature-dependent material…

130

Abstract

Purpose

The purpose of this study is to investigate Thermo-mechanical limit elastic speed analysis of functionally graded (FG) rotating disks with the temperature-dependent material properties. Three different material models i.e. power law, sigmoid law and exponential law, along with varying disk profiles, namely, uniform thickness, tapered and exponential disk was considered.

Design/methodology/approach

The methodology adopted was variational principle wherein the solution was obtained by Galerkin’s error minimization principle. The Young’s modulus, coefficient of thermal expansion and yield stress variation were considered temperature-dependent.

Findings

The study shows a substantial increase in limit speed as disk profiles change from uniform thickness to exponentially varying thickness. At any radius in a disk, the difference in von Mises stress and yield strength shows the remaining stress-bearing capacity of material at that location.

Practical implications

Rotating disks are irreplaceable components in machinery and are used widely from power transmission assemblies (for example, gas turbine disks in an aircraft) to energy storage devices. During operations, these structures are mainly subjected to a combination of mechanical and thermal loadings.

Originality/value

The findings of the present study illustrate the best material models and their grading index, desired for the fabrication of uniform, as well as varying FG disks. Finite element analysis has been performed to validate the present study and good agreement between both the methods is seen.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 4
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 26 December 2022

Lakshman Sondhi, Rakesh Kumar Sahu, Shubhankar Bhowmick and Royal Madan

The purpose of this study was to perform thermo-mechanical deformation and stress analysis in a functionally graded (FG) hollow cylinder considering steady-state temperature…

48

Abstract

Purpose

The purpose of this study was to perform thermo-mechanical deformation and stress analysis in a functionally graded (FG) hollow cylinder considering steady-state temperature distribution under the effect of rotation, gravity and constant heat generation.

Design/methodology/approach

Navier's equation was used to solve the problem, and the obtained results were validated with benchmarks found to be in excellent agreement. The variation of temperature and other material properties such as Young's modulus, density, thermal expansion coefficient and thermal conductivity varied radially as per power-law variation.

Findings

The effect of rotation was found to be vital compared to gravity and heat generation when compared individually and in combination. The results of displacement and stresses were presented for varying grading indices.

Practical implications

FG cylinders have huge industrial applications as it opens the possibility of developing structures with a high strength/weight ratio. The present study will benefit industries in identifying the effective grading index that can be used by industries for fabricating FG structures.

Originality/value

The effect of rotation, body force and heat generation on a cylindrical body has not been studied before. Furthermore, the combined effect of rotation, body force and heat generation has been studied to understand the behaviour of cylinders operating under similar conditions.

Details

International Journal of Structural Integrity, vol. 14 no. 2
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 18 November 2019

Royal Madan, Kashinath Saha and Shubhankar Bhowmick

The limit elastic speed of rotating disk is an important design criterion, as it defines the limit before onset of yielding initiates. The purpose of this paper is to establish…

80

Abstract

Purpose

The limit elastic speed of rotating disk is an important design criterion, as it defines the limit before onset of yielding initiates. The purpose of this paper is to establish the limit elastic speeds for S-FG disks and report the stresses induced at such speeds.

Design/methodology/approach

For S-FGM disk, effective Young’s modulus is calculated using modified rule of mixture and subsequently effective yield stress is also calculated by taking into consideration of stress-strain transfer ratio. The S-FGM disk is subject to centrifugal loading and the stress and deformation characteristics are investigated using variational principle wherein the solution is obtained by Galerkin’s error minimization principle. Based on von-Mises yield criteria, equivalent stress is calculated at different angular speeds till the equivalent stress at any given location in the disk attains the value of effective yield stress at the given location (location of yield initiation). This defines the limit elastic speed for the S-FGM disk (for given n).

Findings

The limit elastic speed of S-FGM disks for a range of grading index (n) and corresponding stresses within the disk are reported. Results are reported for uniform disks of different aspect ratio and the results reported could be used as practical design data.

Practical implications

Functional grading of material in structures opens a new horizon to explore the possibility of manufacturing high strength component at low weight. Material grading plays a significant role in achieving desired material properties, and literature review reveals reporting of numerous grading functions to approximate material distribution in structure.

Originality/value

The work has not been addressed earlier and findings provide a pioneering insight into the performance of S-FG disks.

Details

World Journal of Engineering, vol. 16 no. 6
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 11 August 2022

Royal Madan and Shubhankar Bhowmick

The purpose of this study is to investigate the performance of disks that can be increased by functionally grading the disk in the radial direction; there are several but distinct…

75

Abstract

Purpose

The purpose of this study is to investigate the performance of disks that can be increased by functionally grading the disk in the radial direction; there are several but distinct categories of literature that pertain to the fabrication of disk in the thickness direction, but to the best of the authors’ knowledge, no study has been conducted yet, in which gradient composition changes radially.

Design/methodology/approach

A powder metallurgy technique was used for the fabrication of Al-SiC-based, three-and five-layered functionally graded (FG) disk. The variation of volume fraction of reinforcement particles (SiC) in a disk changes radially. Finite element analysis has been performed to investigate stress distribution in a layered disk.

Findings

The microstructural investigation was carried out under an optical microscope and scanning electron microscopy integrated with EDS, confirming a uniform distribution of SiC in the matrix (Al). Interface microstructure indicates a successful fabrication of FG material because the transition is uniform in the graded layer without any development of crack or void at the interface. The grain size in the layers decreases with the addition of SiC particles. Additionally, the disk hardness increases as the SiC composition in the layer increases.

Practical implications

An FG disk can be used in a wide range of machinery, from power transmission assemblies to energy storage devices (e.g. flywheel, gears, rotors and disk brake).

Originality/value

The proposed powder metallurgy technique could be used in industries for the fabrication of simple to complicated geometries with FG properties.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 2
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 16 September 2024

Royal Madan, Pallavi Khobragade and Shubhankar Bhowmick

This study aimed to analyze the free vibration of a radially graded Ni-Al2O3-based functionally graded (FG) disk with uniform thickness.

11

Abstract

Purpose

This study aimed to analyze the free vibration of a radially graded Ni-Al2O3-based functionally graded (FG) disk with uniform thickness.

Design/methodology/approach

Using the energy method, natural frequencies of rotating and non-rotating disks were determined at the limit elastic angular speed. Material properties were estimated using a modified rule of mixture. Both even and uneven porosity variation effects were considered in the material modeling. Finite element analysis validated the analytical approach.

Findings

The study explored limit angular speeds and natural frequencies across various grading indices, investigating the impact of porosity types and grading indices on these parameters.

Practical implications

Insights from this research are valuable for researchers and design engineers involved in modeling and fabricating porous FG disks, aiding in more effective design and manufacturing processes.

Originality/value

This study contributes to the field by providing a comprehensive analysis of free vibration behavior in radially graded Ni-Al2O3-based FG disks. The incorporation of material modeling considering both even and uneven porosity variation adds originality to the research. Additionally, the validation through finite element analysis enhances the credibility of the findings.

Details

Multidiscipline Modeling in Materials and Structures, vol. 20 no. 6
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 26 January 2021

Royal Madan and Shubhankar Bhowmick

Functionally graded materials are a special class of composites in which material are graded either continuously or layered wise depending upon its applications. With such…

383

Abstract

Purpose

Functionally graded materials are a special class of composites in which material are graded either continuously or layered wise depending upon its applications. With such variations of materials, the properties of structure vary either lengthwise or thickness wise. This paper aims to investigate models for effective estimation of material properties, as it is necessary for industries to identify the properties of composites or functionally graded materials (FGM’s) before manufacturing and also to develop novel material combinations.

Design/methodology/approach

Available models were compared for different material combinations and tested with experimental data for properties such as Young’s modulus, density, coefficient of thermal expansion (CTE) and thermal conductivity. Combinations of metal–ceramic and metal–metal were selected such that their ratios cover a wide range of materials.

Findings

This study reveals different models will be required depending on the material used and properties to be identified.

Practical implications

The results of the present work will help researchers in the effective modeling of composites or FGM’s for any analysis.

Originality/value

This paper presents a comparison and review of various analytical methods with experimental data graphically to find out the best suitable method. For the first time, the Halpin-Tsai model was extended in the analysis of the CTE which shows good approximations.

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Article
Publication date: 26 January 2023

Royal Madan, Shubhankar Bhowmick, Lazreg Hadji and Ali Alnujaie

In this work, the effect of porosity volume fraction, porosity types, material grading index, variable disk profiles and aspect ratio on disk performance was studied by performing…

72

Abstract

Purpose

In this work, the effect of porosity volume fraction, porosity types, material grading index, variable disk profiles and aspect ratio on disk performance was studied by performing limit elastic speed analysis of functionally graded porous rotating disks (PFGM) under thermo-mechanical loading.

Design/methodology/approach

The composition change was varied by employing the power law function. The thermo-mechanical properties of PFGM such as Young's modulus and yield strength were estimated using modified rule of mixture, for density and coefficient of thermal expansion rule of mixture was used. The even and uneven distribution of porosity in a disk was taken as uniform, symmetrical, inner maximum and outer maximum. The problem was then solved with the help of the variational principle and Galerkin's error minimization theory.

Findings

The research reveals that the grading parameter, disk geometry and porosity distribution have a significant impact on the limit elastic speed in comparison to the aspect ratio.

Practical implications

The study determines a range of operable speeds for porous and non-porous disk profiles that the industry can utilize to estimate structural performance.

Originality/value

A finite element investigation was conducted to validate the findings of the present study. Limit elastic analysis of porous FG disks under thermo-mechanical loading has not been studied before.

Details

Multidiscipline Modeling in Materials and Structures, vol. 19 no. 2
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 15 July 2022

Upendra Bajpai, Palash Soni, Vivek Kumar Gaba and Shubhankar Bhowmick

When the temperature of an air conditioning unit’s fin surface goes below its dew point temperature, condensation forms on the unit’s surface. As a result, the cooling coil’s…

69

Abstract

Purpose

When the temperature of an air conditioning unit’s fin surface goes below its dew point temperature, condensation forms on the unit’s surface. As a result, the cooling coil’s performance is compromised. By altering the cross-section and heat conductivity of the fins, the performance of such systems can be improved. This study aims to analyze the thermal performance of longitudinal fins made up of a variable thickness (assuming constant weight) and functionally graded material.

Design/methodology/approach

Different grading parameters are considered for an exponential variation of thermal conductivity. The humidity ratio and the corresponding fin temperatures are assumed to follow a cubic relationship. The Bvp4c solver in MATLAB® is used to solve the differential heat transfer equation resulting from balancing heat transfer in a small segment.

Findings

Validation of the methodology is provided by previous research presented in this area. For different combinations of grading parameters, geometry parameters and relative humidity, the normalized temperature distribution along the fin length and fin efficiency contours are plotted, and the results are very promising.

Originality/value

When compared to the efficiency of an isotropic homogenous rectangular longitudinal fin with optimal geometry and grading parameters, a 17% increase in efficiency under fully wet conditions is measured. When it comes to fin design, these efficiency contour plots are extremely useful.

Details

World Journal of Engineering, vol. 20 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

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