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The purpose of this paper is to make a three-dimensional computational analysis of melting in corrugated pipe inserted system filled with phase change material (PCM). The system was heated from the inner pipe, and temperature of the outer pipe was lower than that of inner pipe. Different geometrical ratio cases and two different temperature differences were tested for their effect on melting time.

A computational analysis through a pipe with corrugated pipe filled with PCM is analyzed. Finite volume method was applied with the SIMPLE algorithm method to solve the governing equations.

The results indicate that the geometrical parameters can be used to control the melting time inside the heat exchanger which, in turn, affect the energy efficiency. The fastest melting time is seen in Case 4 at the same temperature difference which is the major observation of the current work.

Originality of this work is to perform a three-dimensional analysis of melting of PCM in a corrugated pipe inserted pipe.

The purpose of this paper is to solve the problem of a three-dimensional computational analysis for an elliptic-shaped cavity in a pipe under constant temperature.

The three-dimensional computational solution of governing equations was performed by using finite volume method with different temperature difference.

The parafin wax was chosen as a phase change material (PCM), and melting fraction, streamlines and isotherms are formed for different time step. It is found that position B give better results than that of position A, and temperature difference effects the duration of melting of PCM.

The three-dimensional analysis of melting in an ellipsoidal pipe with inner pipe with higher temperature is the main originality of this work.

The purpose of this paper is to analyse the buoyancy flow, mass and heat transfer in coaxial duct under Soret and Dufour effect. The combined effects of the thermal-diffusion and diffusion-thermo coefficients, as well as the Schmidt number, on natural convection in a heated lower coaxial curve were explored using the proposed physical model. The Dufour and Soret effects are taken into consideration in the energy and concentration equations, respectively.

The dominating mathematical models are converted into a set of non-linear coupled partial differential equations, which are solved using a numerical approach. The controlling non-linear boundary value problem is numerically solved using the penalty finite element method with Galerkin’s weighted residual scheme over the entire variety of essential parameters.

It was observed that different parameters were tested such as heat generation or absorption coefficient, buoyancy ratio, Soret coefficient, Dufour coefficient, Lewis number and Rayleigh number. Effect of Rayleigh number, absorption/generation and Dufour coefficient on isotherm are significantly reported. For greater values of Lewis number, maximum mass transfer in duct in the form of molecular particles is produced. Buoyancy ratio parameter decreases the average rate of heat flow and increases its mass transfer.

The main originality of this work is to make an application of Soret and Dufour effects in a coaxial duct in the presence of source sink.

The purpose of this paper is to research on CuO-water nanofluid Non-Darcy flow because of magnetic field. Porous cavity has circular heat source and filled with nanofluid. Lattice Boltzmann Method (LBM) has been used to simulate this problem.

In this research, LBM has been applied as mesoscopic approach to simulate water-based nanofluid free convection. Koo–Kleinstreuer–Li model is used to consider Brownian motion impact on nanofluid properties. Impacts of Rayleigh number, Darcy number, nanofluid volume fraction and Hartmann number on heat transfer treatment are illustrated.

It is found that temperature gradient decreases with rise of while it enhances with augment of Ha. Darcy number can enhance the convective flow.

The originality of this work is to analyze the to investigate magnetic field impact on water based CuO-H₂O nanofluid natural convection inside a porous cavity with elliptic heat source.

The purpose of this study is to work on heat transfer enhancement within different engineering cavities is the major aim of most technical solutions. Such intensification can be obtained by using “smart” liquids known as nanoliquids and solid fins. Therefore, free convective thermal transmission within square nanoliquid chamber under the influence of complex fins is studied. The considered fins are the combination of wall-mounted adiabatic fin and an adiabatic block over this fin.

Influences of the Rayleigh number, location of the local adiabatic block and nanoparticles concentration on liquid motion and energy transport are studied. Finite difference technique was used to solve the governing equations.

It has been ascertained that the energy transport intensification can be reached for the middle position of this local block within the cavity.

The main originality of this work is to use intermittent block in a nanofluid filled cavity under differentially heated conditions. One constant and location of one of the passive element is constant and other one is fixed, which is the intermittent block, is used to control heat and fluid flow. Thus, distance between blocks is allowed to control of the velocity and kinetic energy. In this way, temperature distribution also can be controlled inside the square cross-sectional closed space. Another originality of the work is to use nanoparticle added main flow for this geometry. Thus, energy efficiency can be controlled via adiabatic intermittent blocks without spending any extra energy.

The purpose of this paper is to investigate the hydromagnetic third-grade non-Newtonian fluid flow and heat transfer between two coaxial pipes with a variable radius ratio.

To solve the approximate nonlinear and linear problems with variable coefficients, a trial function was applied. Methods include collocation, least square and Galerkin that can be applied for obtaining these coefficients.

It is revealed that an increase of the non-Newtonian parameter, Hartmann number, and radius ratio leads to an augmentation of the absolute value of the dimensionless velocity, temperature, velocity gradient, and temperature gradient of about 10-60%. Further, the augmentation of Bi₁ reduces the absolute value of the dimensionless temperature profile and dimensionless temperature gradient about three to four times; hence, the dimensionless heat transfer rate reduces. However, the growth of Bi₂ has a contrary impact. Besides, the increase of Pr and Ec leads to an increase in the dimensionless temperature profile and dimensionless temperature gradient; therefore, the dimensionless heat transfer rate increases.

The convection heat transfer on the walls of the pipes is considered, and the nonlinear coupled momentum and energy equations are solved using the least squared method and collocation methods, respectively.

The main aim of this work is to perform a numerical analysis on natural convection with entropy generation in a partially open triangular cavity with a local heat source.

The unsteady governing dimensionless partial differential equations with corresponding initially and boundary conditions were numerically solved by the finite difference method of the second-order accuracy. The effects of dimensionless time is studied, and other governing parameters are Rayleigh number (Ra = 10³ − 10⁵), Prandtl number (Pr = 6.82), heater length (w/L = 0.2, 0.4 and 0.6) and distance of heater ratio (δ/L = 0.3).

An increase in the Rayleigh number leads to an increment of the fluid flow and heat transfer rates. Average Bejan number decreases with Ra as opposed to the average Nusselt number and average entropy generation. High values of Ra characterize a formation of long-duration oscillating behavior for the average Nusselt number and entropy generation.

The originality of this work is to analyze the entropy generation in natural convection in a one side open and partial heater-located cavity. This is a good application for electronical systems or building design.

The purpose of this paper is to study about the natural convection of water-based nanofluid in a partially open trapezoidal cavity under the influence of Brownian diffusion and thermophoresis.

Governing equations formulated in dimensionless stream function – vorticity variables – have been solved by finite difference method with a homemade code C++. Effects of Rayleigh number (Ra = 50-1,000), Lewis number (Le = 10-1,000), buoyancy-ratio parameter (Nr = 0.1-5.0), Brownian motion parameter (Nb = 0.1, 1.0) and thermophoresis parameter (Nt = 0.1, 1.0) on nanofluid flow and heat transfer have been studied.

It is found that high values of Rayleigh and Lewis numbers lead to the homogenization of nanoparticles distributions. For high values of Nt and Nb, heating is more essential and the cavity average temperature rises.

The originality of this work is to analyze natural convection in an open-sided trapezoidal cavity with Brownian diffusion and thermophoresis.

The purpose of this paper is to provide a solution for natural convection in a cavity with a partial heater in case of volumetric heating and analysis of the entropy generation.

The control volume method based on three-dimensional (3D) vorticity-potential vector was applied to solve governing equations of natural convection in a 3D cavity with a fin for different governing parameters as external Rayleigh numbers (103=Ra_E=106), internal Rayleigh numbers 103=Ra_I=106, partition height (0.25=h=0.75) and partition location (0.25=c=0.75). A code was written by using Fortran platform.

The edge of the fin becomes important on entropy generation. The ratio of the Ra_I/Ra_E plays the important role on natural convection and entropy generation. The variation of external Rayleigh number becomes insignificant for the Ra_I/Ra_E>1.

The originality of this work is to analyze the entropy generation and natural convection in a cubical cavity with volumetrically heating.

The main purpose of this work is to arrive at a three-dimensional (3D) numerical solution on mixed convection in a cubic cavity with a longitudinally located triangular fin in different sides.

The 3D governing equations are solved via finite volume technique by writing a code in FORTRAN platform. The governing parameters are chosen as Richardson number, 0.01 ≤ Ri ≤ 10 and thermal conductivity ratio 0.01 ≤ Rc ≤ 100 for fixed parameters of Pr = 0.7 and Re = 100. Two cases are considered for a lid-driven wall from left to right (V+) and right to left (V−).

It is observed that entropy generation due to heat transfer becomes dominant onto entropy generation because of fluid friction. The most important parameter is the direction of the moving lid, and lower values are obtained when the lid moves from right to left.

The main originality of this work is to arrive at a solution of a 3D problem of mixed convection and entropy generation for lid-driven cavity with conductive triangular fin attachments.