Thermal Maragoni Convection of Two-phase Dusty Fluid Flow Along a Vertical Wavy Surface

The paper considers the inuence of thermal Maragoni convection on boundary layer flow of two-phase dusty fluid along a vertical wavy surface. The dimensionless boundary layer equations for two-phase problem are reduced to a convenient form by primitive variable transformation (PVF) and then integrated numerically by employing the implicit finite difference method along with the Thomas Algorithm. The effect of thermal Maragoni convection, dusty water and sinusoidal waveform are discussed in detail in terms of local heat transfer rate, skin friction coefficient, velocity and temperature distributions. This investigation reveals the fact that the water-particle mixture reduces the rate of heat transfer, significantly

A Numerical Solution for the Turbulent Flow of Non-Newtonian Fluids in the Entrance Region of a Heated Circular Tube

Numerical solutions of conservation equations are obtained for turbulent flow of non-Newtonian fluids in a circular tube. The forward marching procedure of Patankar and Spalding^1 was implemented in order to obtain the simultaneous development of the velocity and temperature fields by using the apparent viscosity of fluids. Prandtl\u27s mixing length concept is used to determine the apparent turbulent shearing stress. Furthermore, local and average Nusselt numbers are obtained in the entrance region, as well as in the fully developed region. For the case of the fully developed region, values of the Nusselt numbers are compared both with the experimental data and empirical correlations

A Numerical Solution for the Turbulent Flow of Non-Newtonian Fluids in the Entrance Region of a Heated Circular Tube

Numerical solutions of conservation equations are obtained for turbulent flow of non-Newtonian fluids in a circular tube. The forward marching procedure of Patankar and Spalding^1 was implemented in order to obtain the simultaneous development of the velocity and temperature fields by using the apparent viscosity of fluids. Prandtl\u27s mixing length concept is used to determine the apparent turbulent shearing stress. Furthermore, local and average Nusselt numbers are obtained in the entrance region, as well as in the fully developed region. For the case of the fully developed region, values of the Nusselt numbers are compared both with the experimental data and empirical correlations

Mixed Convection in Vertical Internal Flow of a Micropolar Fluid

The theory of micropolar fluids due to Eringen is used to formulate a set of equations for the flow and heat transfer characteristics of the combined convection micropolar flow in vertical channels. It is found that the microstructure and substructure parameters have significant effects on the flow and thermal fields. By making the Newtonian solvent more and more micropolar, it is possible to obtain drag reduction as well as reduced heat transfer characteristics

Heat and Mass Transfer in Power-Law Nanofluids Over a Nonisothermal Stretching Wall With Convective Boundary Condition

A boundary layer analysis that has been presented for the heat and mass transfer in powerlaw nanofluids over a stretching surface with convective boundary condition are investigated numerically. The surface nanoparticle concentration is kept constant. A power-law model is used for non-Newtonian fluids, whereas Brownian motion and thermophoresis effects are incorporated in the nanofluid model. A similarity transformation is used to reduce mass, momentum, thermal energy, and nanoparticles concentration equations into nonlinear ordinary differential equations which are solved numerically by using a finite difference method. The effects of nanofluid parameters, suction/injection, and convective parameters and generalized Pr and Le numbers on dimensionless functions, skin friction, local Nusselt, and Sherwood numbers are shown graphically. The quantitative comparison of skin friction and heat transfer rates with the published results for special cases is shown in tabular form and is found in good agreement

Mixed convective boundary layer flow over a vertical wedge embedded in a porous medium saturated with a nanofluid: Natural Convection Dominated Regime

A boundary layer analysis is presented for the mixed convection past a vertical wedge in a porous medium saturated with a nano fluid. The governing partial differential equations are transformed into a set of non-similar equations and solved numerically by an efficient, implicit, iterative, finite-difference method. A parametric study illustrating the influence of various physical parameters is performed. Numerical results for the velocity, temperature, and nanoparticles volume fraction profiles, as well as the friction factor, surface heat and mass transfer rates have been presented for parametric variations of the buoyancy ratio parameter Nr, Brownian motion parameter Nb, thermophoresis parameter Nt, and Lewis number Le. The dependency of the friction factor, surface heat transfer rate (Nusselt number), and mass transfer rate (Sherwood number) on these parameters has been discussed

Two-phase Dusty Fluid Flow Along a Rotating Axi-symmetric Round-Nosed Body

This article is concerned with the class of solutions of gas boundary layer containing uniform, spherical solid particles over the surface of rotating axi-symmetric roundnosed body. By using the method of transformed coordinates, the boundary-layer equations for two-phase flow are mapped into a regular and stationary computational domain and then solved numerically by using implicit finite difference method. In this study, a rotating hemisphere is used as a particular example to elucidate the heat transfer mechanism near the surfaces of round nosed bodies. We will also investigate whether the presence of dust particles in carrier fluid disturb the flow characteristics associated with rotating hemisphere or not. A comprehensive parametric analysis is presented to show the influence of the particle loading, the buoyancy ratio parameter and the surface of rotating hemisphere on the numerical findings. In the absence of dust particles, the results are graphically compared with existing data in the open literature and an excellent agreement has been found. It is noted that, the concentration of dust particles parameter, D_p, strongly influence the heat transport rate near the leading edge

Natural Convection Flow of a Two-Phase Dusty Non-Newtonian Fluid Along a Vertical Surface

The aim of this paper is to present a boundary-layer analysis of two-phase dusty non-Newtonian fluid flow along a vertical surface by using a modified power-law viscosity model. This investigation particularly reports the flow behavior of spherical particles suspended in the non-Newtonian fluid. The governing equations are transformed into nonconserved form and then solved straightforwardly by implicit finite difference method. The numerical results of rate of heat transfer, rate of shear stress, velocity and temperature profiles and streamlines and isotherms are presented for wide range of Prandtl number, i.e, (0:7 ≤ Pr ≤ 1000:0), with the representative values of the power-law index n. A good agreement is found between the present and the previous results when compared with some special cases. The key observation from the present study is that the power-law fluids with (n > 1) are more likely to promote the rate of heat transfer near the leading edge

Natural convection flow of two-phase dusty gas with variable thermophysical properties along a vertical wavy surface

The purpose of the present study is to establish the detailed parametric solutions for laminar natural convection flow of two-phase dusty fluid moving along a vertical wavy plate. Typical sinusoidal surface is used to elucidate the heat transport phenomena for the carrier gas having variable thermophysical properties. The governing equations are cast into a system of parabolic partial differential equations by using set of continuous transformations and then the resulting system is integrated through implicit finite difference method. In order to ensure the accuracy, the present numerical results are also compared with the available published results and good compatibility is found between the present and previous results. It is showed that mass concentration parameter, D_p, and the variable thermophysical properties extensively promotes the rate of heat transfer near the uneven surface. It is also established that amplitude of the wavy surface enhances very drastically, which is also due to the variable properties of the fluid

Asymptotic Boundary-Layer Solutions for Mixed Convection from a Vertical Surface in a Micropolar Fluid

Using the theory of micropolar fluids due to Eringen, asymptotic boundary layer solutions are presented to study the combined convection from a vertical semi-infinite plate to a micropolar fluid. Consideration is given to the region close to the leading edge as well as the region far away from the leading edge. Numerical results are obtained for the velocity, angular velocity and temperature distribution. The missing wall values of the velocity, angular velocity and thermal functions are tabulated. Micropolar fluids display drag reduction and reduced surface heat transfer rate when compared to Newtonian fluids