Muhammad Ayub, Muhammad Yousaf Malik, Misbah Ijaz, Marei Saeed Alqarni and Ali Saeed Alqahtani
The purpose of this paper is to explore the novel aspects of activation energy in the nonlinearly convective flow of Walter-B nanofluid in view of Cattaneo–Christov…
Abstract
Purpose
The purpose of this paper is to explore the novel aspects of activation energy in the nonlinearly convective flow of Walter-B nanofluid in view of Cattaneo–Christov double-diffusion model over a permeable stretched sheet. Features of nonlinear thermal radiation, dual stratification, non-uniform heat generation/absorption, MHD and binary chemical reaction are also evaluated for present flow problem. Walter-B nanomaterial model is employed to describe the significant slip mechanism of Brownian and thermophoresis diffusions. Generalized Fourier’s and Fick’s laws are examined through Cattaneo–Christov double-diffusion model. Modified Arrhenius formula for activation energy is also implemented.
Design/methodology/approach
Several techniques are employed for solving nonlinear differential equations. The authors have used a homotopy technique (HAM) for our nonlinear problem to get convergent solutions. The homotopy analysis method (HAM) is a semi-analytical technique to solve nonlinear coupled ordinary/partial differential equations. The capability of the HAM to naturally display convergence of the series solution is unusual in analytical and semi-analytic approaches to nonlinear partial differential equations. This analytical method has the following great advantages over other techniques:
It provides a series solution without depending upon small/large physical parameters and applicable for not only weakly but also strongly nonlinear problems.
It guarantees the convergence of series solutions for nonlinear problems.
It provides us a great choice to select the base function of the required solution and the corresponding auxiliary linear operator of the homotopy.
It provides a series solution without depending upon small/large physical parameters and applicable for not only weakly but also strongly nonlinear problems.
It guarantees the convergence of series solutions for nonlinear problems.
It provides us a great choice to select the base function of the required solution and the corresponding auxiliary linear operator of the homotopy.
Brief mathematical description of HAM technique (Liao, 2012; Mabood et al., 2016) is as follows. For a general nonlinear equation:
where N denotes a nonlinear operator, x the independent variables and u(x) is an unknown function, respectively. By means of generalizing the traditional homotopy method, Liao (1992) creates the so-called zero-order deformation equation:
here q∈[0, 1] is the embedding parameter, H(x) ≠ 0 is an auxiliary function, h(≠ 0) is a nonzero parameter, L is an auxiliary linear operator, uo(x) is an initial guess of u(x) and
Expanding
If the initial guess, the auxiliary linear operator, the auxiliary h and the auxiliary function are selected properly, then the series (4) converges at q=1, then we have:
By defining a vector
where:
Applying L−1 on both sides of Equation (6), we get:
In this way, we obtain um for m ⩾ 1, at mth-order, we have:
Findings
It is evident from obtained results that the nanoparticle concentration field is directly proportional to the chemical reaction with activation energy. Additionally, both temperature and concentration distributions are declining functions of thermal and solutal stratification parameters (P1) and (P2), respectively. Moreover, temperature Θ(Ω1) enhances for greater values of Brownian motion parameter (Nb), non-uniform heat source/sink parameter (B1) and thermophoresis factor (Nt). Reverse behavior of concentration ϒ(Ω1) field is remarked in view of (Nb) and (Nt). Graphs and tables are also constructed to analyze the effect of different flow parameters on skin friction coefficient, local Nusselt number, Sherwood numbers, velocity, temperature and concentration fields.
Originality/value
The novelty of the present problem is to inspect the Arrhenius activation energy phenomena for viscoelastic Walter-B nanofluid model with additional features of nonlinear thermal radiation, non-uniform heat generation/absorption, nonlinear mixed convection, thermal and solutal stratification. The novel aspect of binary chemical reaction is analyzed to characterize the impact of activation energy in the presence of Cattaneo–Christov double-diffusion model. The mathematical model of Buongiorno is employed to incorporate Brownian motion and thermophoresis effects due to nanoparticles.
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Divya Divya, Savita Savita and Sandeepa Kaur
This paper aims to provide a conceptual framework containing SERVQUAL original dimensions and add two additional dimensions: patient satisfaction and loyalty in the hospital SQ…
Abstract
Purpose
This paper aims to provide a conceptual framework containing SERVQUAL original dimensions and add two additional dimensions: patient satisfaction and loyalty in the hospital SQ model that demonstrates the relationship between hospital service quality, patient satisfaction and loyalty from patients’ perspective.
Design/methodology/approach
This research conducted a thorough literature review using specific keywords and electronic databases, adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Through analysis, the key dimensions of service quality in Indian hospitals were identified, with the addition of patient satisfaction and loyalty as variables. Of 1,000 initially downloaded papers, 497 were included.
Findings
While many researchers rely on the SERVQUAL model, some introduce new or modified dimensions, often renaming existing ones. This study identifies the RATER factors as the main dimensions patients use to evaluate hospital services. This study finds a positive relationship between service quality, patient satisfaction and loyalty.
Practical implications
An understanding of how health-care service quality dimensions, directly and indirectly, affect patient satisfaction and loyalty is important for hospital marketing managers. This study helps them take action to improve patient satisfaction, which encourages patients to be loyal.
Originality/value
This research provides a comprehensive framework for measuring health-care service quality, combining SERVQUAL dimensions and new variables. This study offers useful insights for academics and health-care professionals, promoting more accurate measurement and enhancement of service quality. The use of PRISMA in this context is also innovative, as it is less common in administrative health-care research.
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F. Jayakanth, K. Maly, M. Zubair and L. Aswath
A dynamic approach to making legacy databases, like CDS/ISIS, interoperable with OAI‐compliant digital libraries (DLs).
Abstract
Purpose
A dynamic approach to making legacy databases, like CDS/ISIS, interoperable with OAI‐compliant digital libraries (DLs).
Design/methodology/approach
There are many bibliographic databases that are being maintained using legacy database systems. CDS/ISIS is one such legacy database system. It was designed and developed specifically for handling textual data. Over the years, many databases have been developed using this package. There is, however, no mechanism supported by the package for seamless interoperability of databases. The open archives initiative (OAI) addresses the issue of interoperability by using a framework to facilitate the discovery of content stored in distributed archives or bibliographic databases through the use of the OAI Protocol for Metadata Harvesting (OAI‐PMH). The protocol is becoming a de facto standard for interoperability of DLs. Many of the legacy database systems that are in use today, to the best of our knowledge, for various reasons, are not OAI‐compliant. This makes it difficult for the legacy databases to share their metadata automatically. There are two possible approaches to make legacy databases OAI‐compliant – static and dynamic. In this paper, we discuss the dynamic approach to make CDS/ISIS databases OAI‐compliant.
Findings
The dynamic approach is a simple way to make legacy databases OAI‐compliant so that they become interoperable with other OAI‐compliant DLs.
Research limitations/implication
Developing a general‐purpose tool to make legacy databases OAI‐compliant may be difficult as the driver software needed for database connectivity may not be easily available. Also, the structure of the databases are likely be so varied that identifying the fields that make up the databases programmatically will be very challenging.
Originality/value
Provides a dynamic approach to making legacy databases interoperable with OAI‐compliant libraries.
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F. Jayakanth, K. Maly, M. Zubair and L. Aswath
To make CDS/ISIS databases OAI‐compliant.
Abstract
Purpose
To make CDS/ISIS databases OAI‐compliant.
Design/methodology/approach
One of the biggest obstacles for information dissemination to a user community is that many digital libraries or bibliographic databases use heterogeneous technologies that inhibit interoperability. The Open Archives Initiative (OAI) addresses interoperability by using a framework to facilitate the discovery of content stored in distributed archives or bibliographic databases through the use of the OAI Protocol for Metadata Harvesting (OAI‐PMH). Though the OAI‐PMH is becoming the de facto standard, many of the legacy databases or bibliographic systems, for various reasons, are not OAI‐compliant. CDS/ISIS is one such database system. In this paper, we discuss the static repository (SR) approach to make CDS/ISIS databases OAI‐compliant. The records from a CDS/ISIS database are exported onto a file and the exported records are then converted to the SR XML file format. The SR file is made OAI‐compliant either by ingesting it into the Kepler Archivelet or through the intermediation of a static repository gateway (SRG).
Findings
The SR is a simple approach for making bibliographic records contained in non‐OAI‐compliant systems, OAI‐compliant.
Research limitations/implications
The SR approach is meant for records, which are relatively static. If the OAI‐compliance is achieved through the SRG, then the number of records contained in a SR file should not exceed 5,000. However, if the SR file is ingested into the Kepler Archivelet, then there is no restriction on the number of records contained in a SR file.
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Prashant Dineshbhai Vyas, Harish C. Thakur and Veera P. Darji
This paper aims to study nonlinear heat transfer through a longitudinal fin of three different profiles.
Abstract
Purpose
This paper aims to study nonlinear heat transfer through a longitudinal fin of three different profiles.
Design/methodology/approach
A truly meshfree method is used to undertake a nonlinear analysis to predict temperature distribution and heat-transfer rate.
Findings
A longitudinal fin of three different profiles, such as rectangular, triangular and concave parabolic, are analyzed. Temperature variation, along with the fin length and rate of heat transfer in steady state, under convective and convective-radiative environments has been demonstrated and explained. Moving least square (MLS) approximants are used to approximate the unknown function of temperature T(x) with Th(x). Essential boundary conditions are imposed using the penalty method. An iterative predictor–corrector scheme is used to handle nonlinearity.
Research limitations/implications
Modelling fin in a convective-radiative environment removes the assumption of no radiation condition. It also allows to vary convective heat-transfer coefficient and predict the closer values to the real problems for the corresponding fin surfaces.
Originality/value
The meshless local Petrov–Galerkin method can solve nonlinear fin problems and predict an accurate solution.
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Muhammad Sohail and Sana Tariq
Thermal and species transport of magneto hydrodynamic Casson liquid over a stretched surface is investigated theoretically in this examination for the three-dimensional boundary…
Abstract
Purpose
Thermal and species transport of magneto hydrodynamic Casson liquid over a stretched surface is investigated theoretically in this examination for the three-dimensional boundary layer flow of a yield exhibiting material. The phenomenon of heat and species relocation is based upon modified Fourier and Fick’s laws that involves the relaxation times for the transportation of heat and mass. Conservation laws are modeled under boundary layer analysis in the Cartesian coordinates system. The purpose of this paper is to find the influence of different emerging parameters on fluid velocity, temperature and transport of species.
Design/methodology/approach
Reconstructed nonlinear boundary layer ordinary differential equations are analyzed through eigenvalues and eigenvectors. Due to the complexity and non-existence of the exact solution of the transformed equations, a convergent series solution by the homotopy algorithm is also derived. The reliability of the applied scheme is presented by comparing the obtained results with the previous findings.
Findings
Physical quantities of interest are displayed through graphs and tables and discussed for sundry variables. It is discerned that higher magnetic influence slows down fluid motion, whereas concentration and temperature profiles upsurge. Reliability of the recommended scheme is monitored by comparing the obtained results for the dimensionless stress as a limiting case of previous findings and an excellent agreement is observed. Higher values of Schmidt number reduce the concentration profile, whereas mounting the values of Prandtl number reduces the dimensionless temperature field. Moreover, heat and species transfer rates increase by mounting the values of thermal and concentration relaxation times.
Originality/value
The phenomenon of heat and species relocation is based upon modified Fourier and Fick’s laws which involves the relaxation times for the transportation of heat and mass. Conservation laws are modeled under boundary layer analysis in the Cartesian coordinates system.
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G. Sowmya, B.J. Gireesha and O.D. Makinde
The purpose of this paper is to study the thermal behaviour of a fully wet porous fin of longitudinal profile. The significance of radiative and convective heat transfer has been…
Abstract
Purpose
The purpose of this paper is to study the thermal behaviour of a fully wet porous fin of longitudinal profile. The significance of radiative and convective heat transfer has been scrutinised along with the simultaneous variation of surface emissivity, heat transfer coefficient and thermal conductivity with temperature. The emissivity of the surface and the thermal conductivity are considered as linear functions of the local temperature between fin and the ambient. Darcy’s model was considered to formulate the heat transfer equation. According to this, the porous fin permits the flow to penetrate through it and solid–fluid interaction occurs.
Design/methodology/approach
Runge–Kutta–Fehlberg fourth–fifth-order method has been used to solve the reduced non-dimensionalized ordinary differential equation involving highly nonlinear terms.
Findings
The impact of pertinent parameters, such as convective parameter, radiative parameter, conductivity parameter, emissivity parameter, wet porous parameter, etc., on the temperature profiles were elaborated mathematically with the plotted graphs. The heat transfer from the fin enhances with the rise in convective parameter.
Originality/value
The wet nature of the fin enhances heat transfer and in many practical applications the parameters, such as thermal conductivity, heat transfer coefficient as well as surface emissivity, vary with temperature. Hence, the main objective of the current study is to depict the significance of simultaneous variation in surface emissivity, heat transfer coefficient and thermal conductivity with respect to temperature under natural convection and radiation condition in a totally wetted longitudinal porous fin.
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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…
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.
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G. Sowmya, Gireesha B.J., Muhammad Ijaz Khan, Shaher Momani and Tasawar Hayat
The purpose of this study is to conduct a numerical computation to analyse the thermal attribute and heat transfer phenomenon of a fully wetted porous fin of a longitudinal…
Abstract
Purpose
The purpose of this study is to conduct a numerical computation to analyse the thermal attribute and heat transfer phenomenon of a fully wetted porous fin of a longitudinal profile. The fin considered is that of a functionally graded material (FGM). Based on the spatial dependency of thermal conductivity, three cases such as linear, quadratic and exponential FGMs are analysed.
Design/methodology/approach
The governing equations are nondimensionalised and solved by applying Runge-Kutta-Fehlberg fourth-fifth order technique.
Findings
The parametric investigation is executed to access the significance of the pertinent parameters on the thermal feature of the fin and heat transmit rate. The outcomes are portrayed in a graphical form.
Originality/value
No such study has yet been published in the literature.
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This paper aims to seek purely analytical results relying on the physical parameters including the temperature jump parameter.
Abstract
Purpose
This paper aims to seek purely analytical results relying on the physical parameters including the temperature jump parameter.
Design/methodology/approach
The exponential fin profiles and heat transfer enhancement influenced by a temperature jump at the base are the main targets of this paper.
Findings
The introduced temperature slip at the base penetrates through the surface of the fin and reorganizes the distribution of temperature all over the surface. The overall impact of the temperature jump on the fin efficiency is such that it acts to lower the fin efficiency. However, the efficiency of the exponential fin is increasing for growing shape exponential fins as compared to the rectangular and decaying ones. Hence, exponential fins amenable to certain temperature jump has significance in technological cooling processes. Finally, the optimum dimensions regarding the base fin thickness and the fin length of the exponential profiles are assessed by means of optimizing the base heat transfer rate given a cross-sectional area.
Originality/value
Exact solutions are provided for optimum exponential type fins subjected to a temperature jump. The optimum dimensions regarding the base fin thickness and the fin length of the exponential profiles are assessed.