Viscous dissipation effect on steady natural convection Couette flow with convective boundary condition

The present article explores the effect of viscous dissipation on steady natural convection Couette flow subject to convective boundary condition. Due to the nonlinearity and coupling of the governing equations in the present situation, the homotopy perturbation method was employed to obtain the solutions of the energy and momentum equations. The impacts of the controlling parameters were investigated and discussed graphically. In the course of investigation, it was found that fluid temperature increases with an increase in viscous dissipation while the reverse trend was observed in fluid velocity. However, it was also discovered that heat generation leads to a decrease in the rate of heat transfer on the heated plate and it increases on the cold plate. Finally, it was concluded that the velocity boundary layer thickness increases with an increase in Biot number.

Hydrodynamic and heat transfer analysis of dissimilar shaped nanoparticles-based hybrid nanofluids in a rotating frame with convective boundary condition

Solar thermal systems have low efficiency due to the working fluid's weak thermophysical characteristics. Thermo-physical characteristics of base fluid depend on particle concentration, diameter, and shapes. To assess a nanofluid's thermal performance in a solar collector, it is important to first understand the thermophysical changes that occur when nanoparticles are introduced to the base fluid. The aim of this study is, therefore, to analyze the hydrodynamic and heat characteristics of two different water-based hybrid nanofluids (used as a solar energy absorber) with varied particle shapes in a porous medium. As the heat transfer surface is exposed to the surrounding environment, the convective boundary condition is employed. Additionally, the flow of nanoliquid between two plates (in parallel) is observed influenced by velocity slip, non-uniform heat source-sink, linear thermal radiation. To make two targeted hybrid nanofluids, graphene is added as a cylindrical particle to water to make a nanofluid, and then silver is added as a platelet particle to the graphene/water nanofluid. For the second hybrid nanofluid, CuO spherical shape particles are introduced to the graphene/water nanofluid. The entropy of the system is also assessed. The Tiwari-Das nanofluid model is used. The translated mathematical formulations are then solved numerically. The physical and graphical behavior of significant parameters is studied.

Effects of Heat Generation/Absorption on Magnetohydrodynamics Flow Over a Vertical Plate with Convective Boundary Condition

Heat generation effect in a steady two-dimensional magnetohydrodynamics (MHD) flow over a moving vertical plate with a medium porosity has been studied. By similarity transformation variables, the coupled non-linear ordinary differential equations describing the model are obtained. The resulting equation is then solved, using Galerkin Weighted Residual Method (GWRM), where the effect of heat generation, Magnetic Parameter as well as other physical parameters encountered were examined and discussed. Some of the major findings were that increase in heat generation and convective heat parameter enhances the plate surface temperature as well as temperature field which allows the thermal effect to penetrate deeper into the quiescent fluid.

Combined Convective Transport of Brinkman-viscoelastic Fluid Across Horizontal Circular Cylinder with Convective Boundary Condition

Traditional heat transfer fluids frequently encounter several limitations in the heat transfer process, due to the lower thermal conductivity in heat transfer process industries, and also has an impact on the performance of heat transfer in industrial sectors. In order to overcome the problem, researchers have currently considered an alternative development of heat transfer of fluids. Hence, this study will concentrate on the problem of steady combined convective transport. In particular, the flow of Brinkman-viscoelastic fluid over a horizontal circular cylinder with the influence of convective boundary condition (CBC) was investigated. Using the necessary similarity transformation, the governing equations were converted into a less complicated form and numerically solved by using Runge-Kutta-Fehlberg-method, which was programmed in Maple software. The influence of Biot number, combined convection, Brinkman and viscoelastic parameters are analyzed and demonstrated in graphs and tables. Numerical result showed that the fluid velocity increased with improving conjugate and combined convection parameter, but decreased with increasing Brinkman and viscoelastic parameter. It is also discovered the reverse trend on temperature profiles.

Flow and Heat Transfer of MHD Dusty Nanofluid Toward Moving Plate with Convective Boundary Condition

This paper considers the flow and heat transfer characteristics of dusty nanofluid over a moving plate in the presence of magnetohydrodynamic (MHD) with convective boundary condition. Two types of nanofluid namely CuO-water and Al2O3-water permeated with dust particles are considered. The governing partial differential equations are converted into a system of non-linear ordinary differential equations using similarity transformation, then the non-linear ordinary differential equations are solved using shooting method with fourth-fifth order Runge-Kutta Fehlberg method (RKF45). The influence of non-dimensional governing parameters such as velocity ratio parameter, magnetic field parameter, volume fraction of the nanoparticle, volume fraction of the dust particle, mass concentration of the dust particle, fluid particle interaction parameter for velocity, fluid particle interaction parameter for temperature and Biot number on the velocity and temperature profiles for fluid and dust phases of CuO-water and Al2O3-water dusty nanofluids are discussed and presented through graphs. The skin friction coefficient and Nusselt number are discussed and presented in tabular form.

Impact of surface temperature and convective boundary conditions on a Nanofluid flow over a radially stretched Riga plate

The current work provides the optimal homotopic analytical methodology for the steady circulation over a non-isothermal radially stretched Riga plate/disc unit. The attributes of the heat, along with the mass transfer process, are assessed in the existence of variable transport and magnetic features. Radial stretched Riga disc is considered along with additional realistic boundary heating conditions, namely, prescribed surface temperature as well as prescribed surface concentration, convective boundary conditions and also zero mass flux concentration on the surface area of the Riga disc. The model tracks Brownian motion as well as the thermal diffusion of nanoparticles in fluid circulation all at once. Regulating equations, which are highly coupled, are changed right into non-dimensional equations using appropriate transformations of similarity. Through assembling series solutions, the resulting framework is planned and examined. Graphic summaries are offered for the rheological qualities of various parameters in size for velocity, temperature, as well as nanoparticles. The modified Hartman number improves the velocity distribution and reduces the temperature distribution in both prescribed surface temperature and convective boundary condition cases. The effect of the chemical reaction parameter shows the reduced concentration distribution for the prescribed surface temperature case. In contrast, it is precisely the opposite in the convective boundary condition case.

Effect of convective boundary condition on unsteady flow of CNT-H2O nanofluid towards a stagnation-point on a shrinking/expanding flat sheet

A model study of unsteady stagnation-point flow of most important nanoparticles, that is, carbon nanotubes suspended nanofluid towards shrinking/expanding sheet with convective boundary condition is demonstrated. Two types of carbon nanotubes, namely, single-wall and multi-wall nanotubes are carefully considered. Numerical solutions of converted equations from governing equation of the problem are obtained and those are graphically presented. Similar to without carbon nanotubes case, dual and unique solutions in specific ranges of velocity ratio parameter are achieved. Analysis disclosures that the condition on range where dual solutions exist is unaltered with solid-volume fraction and type of carbon nanotubes. The surface drag-force and heat transfer rate from wall are larger for single-walled carbon nanotubes nanofluid than multi-walled carbon nanotubes nanofluid. An increment in the parameter related to convective boundary condition generates high rate of heat transfer. After stability analysis, it is identified that in case of dual solutions, upper branch is stable and lower branch is unstable, while unique solution is always stable.