10 research outputs found
Double-diffusive natural convection with Soret/Dufour effects and energy optimization of Nano-Encapsulated Phase Change Material in a novel form of a wavy-walled I-shaped domain
Background: As building segment grows in parallel with amplifying population, the necessity for consumption of energy needed to passive and active heating or cooling buildings for thermal comfort increases. Schemes such as developing green buildings for sustainable architecture were utilized to address this issue. The utilization of Phase Change Materials (PCMs) with the aim of active and passive cooling or heating of buildings illustrates a promising and modern technique. Methods: This study's objective is to perform a numerical analysis using the finite element method, FEM for modeling free convection produced by double-diffusion (DDNC) with Soret/Dufour effects of Nano-Encapsulated PCMs within an I-shaped enclosure equipped with a novel type of corrugated vertical walls subjected to Neumann thermal and solutal conditions. Findings: Results are interpreted and assessed in relation to the governing factors, such as buoyancy ratio (N), Rayleigh and Lewis numbers (Ra, Le), the height of corrugated walls (a), Stefan number (Ste), non-dimensional fusion temperature (胃f), Dufour (Df), and Soret (Sr) parameters. High values of N and Ra, and low values of Le and a, caused in the highest rate of heat and mass exchange. The irreversibilities due to the heat and mass transfer effects increase as the flow intensity within the system decrease. Decreasing the latent heat of the NEPCM cores and increasing their fusion temperature lowering the heat transfer rates, while improving mass transfer rates. This configuration can help in the design of the storage tank in hydronic apparatus for cooling, heating, and domestic hot water in buildings
Effect of magnetic field on the motion of two rigid spheres embedded in porous media with slip surfaces
A semi-analytical study for the Stokes flow approximation caused by two solid spheres of different sizes with slip surfaces, immersed in a porous medium in the presence of a transverse magnetic field, is investigated. The two spheres are translating with different velocities along the line joining their centers. A general solution is developed from the superposition of the essential solutions in two spherical frameworks with origins located at the centers of the two spheres. Numerical results for the normalized hydrodynamic drag force acting on each sphere are obtained with good convergence for various values of the Hartmann number which characterizes the presence of magnetic field, the permeability parameter which characterizes the porous medium, separation parameter, and velocity and size ratios of the spheres. Our drag results are in good agreement with the available solutions in the literature in the cases of no-slip surfaces and when the porous medium turns into a pure fluid
Stochastic wave propagation in magneto-thermoelastic materials subjected to the change in electrical and thermal conductivity
This paper presents the results of an investigation that focuses on the stochastic wave propagation that occurs within an elastic medium when the thermoelectric properties are taken into consideration. It has been found that there is a clear association between the characteristics of electrical conductivity and thermal conductivity. As a result, the current topic focuses on the influence a magnetic field has on the variable thermal conductivity and electrical conductivity that exists within a material. This is done within the context of dual phase lag thermoelasticity. Several parameters are incorporated into the governing equations, which exhibit coupling. Thermal shock has been applied to the boundary of the medium that represents the non-traction barrier. At the border of the problem, stochasticity is imposed in order to make the problem appear more realistic. Within the boundary conditions, it is presumed that the white-noise function is present. Utilizing the Laplace transform method is the approach that is taken to address the issue. It is possible to determine the inverse transformations using numerical approximation approaches. Both graphical and visual analyses are performed on the dataset. In conclusion, graphical representations are utilized in order to make comparisons between the deterministic and stochastic solutions of all physical fields
Response of photo-elasto-electric semiconductor porosity medium according to changing thermal conductivity with two-temperature
This study examines a new model for a solid semiconductor porosity medium with variable thermal conductivity under photo-thermoelastic conditions using two-temperature theory. A normal mode analysis is carried out to solve the equations in two dimensions analytically while taking into account the linear relationship between thermal conductivity and temperature. Physical fields, such as carrier density distribution, temperature, stress, and displacement, are then determined. The interaction between plasma and elastic waves is also considered. The simulation is conducted using silicon material, and the numerical calculations are illustrated graphically. This study investigates the effects of different porosity parameters (with and without porosity), thermal variable conductivity, and the two-temperature parameter on the physical field values
Accommodation of climate change in coastal areas of cameroon: selection of household-level protection options
Climate change, Coastal residents, Protection options,