Numerical Investigation of Unsteady Mixed Convection Flow

2007 ◽  
Author(s):  
Param Jeet Singh ◽  
S. Roy
Keyword(s):  
Mixed Convection ◽  
Nonlinear Partial Differential Equations ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Stream Velocity ◽  
Mixed Convection Flow ◽  
Boundary Layer Equations ◽  
Unsteady Mixed Convection ◽  
Implicit Finite Difference Scheme ◽  
Effect Of Surface

Unsteady mixed convection flow over a vertical slender cylinder under the combined effects of buoyancy force and thermal diffusion with injection/suction has been studied where the slender cylinder is inline with the flow. The unsteadiness is introduced by time dependent free stream velocity of the fluid. The effect of surface curvature is also taken into account, especially for the applications such as wire and fiber drawing, where accurate predictions are desired. The governing boundary layer equations along with the boundary conditions are first converted into dimensionless form by a non similar transformation, and then resulting system of coupled nonlinear partial differential equations is solved by an implicit finite difference scheme in combination with the quasilinearization technique. The effects of various parameters on velocity, temperature profiles, on skin friction coefficient and heat transfer rate at the wall are reported in the present study.

scholarly journals Radiation and Magnetic Field Impacts on Time-Dependent Mixed Convection Flow and Heat Transmission of Maxwellian Fluid Past A Stretching Sheet

Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 208
Author(s):  
Sajjad Haider ◽  
Imran Syed Muhammad ◽  
Yun-Zhang Li ◽  
Faraz ◽  
Adnan Saeed Butt
Keyword(s):  
Magnetic Field ◽  
Mixed Convection ◽  
Transmission Rate ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Heat Transmission ◽  
Boundary Layer Equations ◽  
Flow Parameters ◽  
Unsteady Mixed Convection

The current study was devoted to explicating the impacts of heat transmission in an unsteady mixed convection flow of an upper convected Maxwell (UCM) fluid passing over a continuously stretching surface under the influence of radiation and magnetic field. Appurtenant similarity transmutations were adopted in order to express the constitutive boundary layer Equations of flow and heat transmission in non-dimensionalized form. The reduced system of partial differential Equations was solved by implementing the implicit finite difference method (IFDM). Our center of attention was to scrutinize the behavior of influential flow parameters on some significant features of flow and heat transmission, which were briefly examined, discussed, and presented in both graphical and tabular formats. Finally, a comparison was established with existing literature in limiting cases to support the present results, and a good agreement was found, corroborating our work. It was predicted that the thermal diffusion rate could be controlled by varying the Prandtl number. Moreover, a rise in radiation and magnetic field parameters reduced the skin friction coefficient and led to enhance the heat transmission rate at the surface. The outcomes of the study might have viable implementations in order to improve the quality of industrial products.

scholarly journals Unsteady mixed convection flow from a slender cylinder due to impulsive change in wall velocity and temperature

2013 ◽  
Vol 17 (4) ◽  
pp. 1023-1034 ◽  
Author(s):  
P.M. Patil ◽  
I. Pop
Keyword(s):  
Mixed Convection ◽  
Skin Friction Coefficient ◽  
Temperature Fields ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Local Skin ◽  
Wall Velocity ◽  
Boundary Layer Equations ◽  
Linear Partial Differential Equations ◽  
Unsteady Mixed Convection

An unsteady mixed convection flow of a viscous incompressible fluid over a non-permeable linear stretching vertical slender cylinder is considered to investigate the combined effects of buoyancy force and thermal diffusion. It is assumed that the slender cylinder is in line with the flow. The unsteadiness in the flow and temperature fields is caused due to the impulsive change in the wall velocity and wall temperature of linearly stretching vertical slender cylinder. The effect of surface curvature is also taken into account, particularly for the applications as wire and fiber drawing where exact predictions are expected. The governing boundary layer equations are transformed into a non-dimensional form by a group of non-similar transformations. The resulting system of coupled non-linear partial differential equations is solved by an implicit finite difference scheme in combination with the quasi-linearization technique. Numerical computations are performed to understand the physical situations of linear stretching surface for different values of parameters to display the velocity and temperature profiles graphically. The numerical results for the local skin-friction coefficient and local Nusselt number are also presented. Present results are compared with previously published work and are found to be in excellent agreement.

Unsteady Mixed Convection From a Moving Vertical Slender Cylinder

2005 ◽  
Vol 128 (4) ◽  
pp. 368-373 ◽  
Author(s):  
S. Roy ◽  
D. Anilkumar
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Skin Friction Coefficient ◽  
Surface Mass ◽  
Boundary Layer Equations ◽  
Surface Mass Transfer ◽  
Laminar Mixed Convection ◽  
Unsteady Mixed Convection ◽  
Implicit Finite Difference Scheme ◽  
Momentum And Heat Transfer

A general analysis has been developed to study flow and heat transfer characteristics of an unsteady laminar mixed convection on a continuously moving vertical slender cylinder with surface mass transfer, where the slender cylinder is inline with the flow. The unsteadiness is introduced by the time-dependent velocity of the slender cylinder as well as that of the free stream. The calculations of momentum and heat transfer on slender cylinders considered the transverse curvature effect, especially in applications such as wire and fiber drawing, where accurate predictions are required. The governing boundary layer equations along with the boundary conditions are first cast into a dimensionless form by a nonsimilar transformation, and the resulting system of nonlinear coupled partial differential equations is then solved by an implicit finite difference scheme in combination with the quasi-linearization technique. Numerical results are presented for the skin friction coefficient and Nusselt number. The effects of various parameters on the velocity and temperature profiles are also reported here.

scholarly journals Effects of Thermal Radiation on Mixed Convection Flow of a Micropolar Fluid from an Unsteady Stretching Surface with Viscous Dissipation and Heat Generation/Absorption

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Khilap Singh ◽  
Manoj Kumar
Keyword(s):  
Mixed Convection ◽  
Thermal Radiation ◽  
Heat Generation ◽  
Micropolar Fluid ◽  
Numerical Solutions ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Stretching Surface ◽  
Local Skin ◽  
Unsteady Mixed Convection

A numerical model is developed to examine the effects of thermal radiation on unsteady mixed convection flow of a viscous dissipating incompressible micropolar fluid adjacent to a heated vertical stretching surface in the presence of the buoyancy force and heat generation/absorption. The Rosseland approximation is used to describe the radiative heat flux in the energy equation. The model contains nonlinear coupled partial differential equations which have been converted into ordinary differential equation by using the similarity transformations. The dimensionless governing equations for this investigation are solved by Runge-Kutta-Fehlberg fourth fifth-order method with shooting technique. Numerical solutions are then obtained and investigated in detail for different interesting parameters such as the local skin-friction coefficient, wall couple stress, and Nusselt number as well as other parametric values such as the velocity, angular velocity, and temperature.

scholarly journals MHD Nonlinear Mixed Convection Flow of Micropolar Nanofluid over Nonisothermal Sphere

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Wubshet Ibrahim ◽  
Chaluma Zemedu
Keyword(s):  
Boundary Layer ◽  
Mixed Convection ◽  
Mathematical Formulation ◽  
Magnetic Field Effect ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Nonlinear Boundary Value Problems ◽  
Micropolar Nanofluid ◽  
Nonlinear Mixed Convection

In this paper, two-dimensional steady laminar boundary layer flow of a nonlinear mixed convection flow of micropolar nanofluid with Soret and magnetic field effect over a nonisothermal sphere is evaluated. The mathematical formulation for the flow problem has been made with appropriate similarity transformation and dimensionless variables, and the main nonlinear boundary value problems were reduced into mixed high-order nonlinear ordinary differential equations. Solution for velocity, microrotation, temperature, and concentration has been obtained numerically. The equations were calculated using method bvp4c from Matlab software for various quantities of main parameters. The effects of various parameters on skin friction coefficient f″0, wall duo stress coefficient -G′0, and convection mass transfer coefficient -Φ′0 are analysed and presented through the graphs and tables. The convergence test has been maintained. For the number of points greater than the suitable mesh number of points, the precision is not influenced but the set time is increased. Moreover, a comparison with a previous paper, obtainable in the literature, has been presented and an excellent agreement is obtained. The findings indicate that an increase in the values of nonisothermal parameters (m, P), magnetic Ma, thermal and solutal nonlinear convection (λ, s) parameter, and Soret number is to enhance the temperature difference between the boundary layer and ambient fluid to diffuse which increases the velocity profile f′ζ and their boundary layer thicknesses near the surface of the sphere.

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