scholarly journals Multiple shaped nano-particles influence on thermal conductivity of fluid flow between inflexible and sinusoidal walls

2021 ◽  
Vol 25 ◽  
pp. 100930
Author(s):  
T. Salahuddin ◽  
Abdul Mosan Bashir ◽  
Mair Khan ◽  
We-Fing Xia
Keyword(s):  
Thermal Conductivity ◽  
Fluid Flow ◽  
Nano Particles

scholarly journals Effect of magnetized variable thermal conductivity on flow and heat transfer characteristics of unsteady Williamson fluid

2020 ◽  
Vol 9 (1) ◽  
pp. 338-351
Author(s):  
Usha Shankar ◽  
N. B. Naduvinamani ◽  
Hussain Basha
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Fluid Flow ◽  
Velocity Profile ◽  
Variable Thermal Conductivity ◽  
Flow Index ◽  
Williamson Fluid ◽  
Flow Equations ◽  
Velocity Parameter ◽  
Squeezed Flow

AbstractA two-dimensional mathematical model of magnetized unsteady incompressible Williamson fluid flow over a sensor surface with variable thermal conductivity and exterior squeezing with viscous dissipation effect is investigated, numerically. Present flow model is developed based on the considered flow geometry. Effect of Lorentz forces on flow behaviour is described in terms of magnetic field and which is accounted in momentum equation. Influence of variable thermal conductivity on heat transfer is considered in the energy equation. Present investigated problem gives the highly complicated nonlinear, unsteady governing flow equations and which are coupled in nature. Owing to the failure of analytical/direct techniques, the considered physical problem is solved by using Runge-Kutta scheme (RK-4) via similarity transformations approach. Graphs and tables are presented to describe the physical behaviour of various control parameters on flow phenomenon. Temperature boundary layer thickens for the amplifying value of Weissenberg parameter and permeable velocity parameter. Velocity profile decreased for the increasing squeezed flow index and permeable velocity parameter. Increasing magnetic number increases the velocity profile. Magnifying squeezed flow index magnifies the magnitude of Nusselt number. Also, RK-4 efficiently solves the highly complicated nonlinear complex equations that are arising in the fluid flow problems. The present results in this article are significantly matching with the published results in the literature.

Quadratic Mixed Convection Stagnation-Point Flow in Hydromagnetic Casson Nanofluid over a Nonlinear Stretching Sheet with Variable Thermal Conductivity

2021 ◽  
Vol 409 ◽  
pp. 95-109
Author(s):  
Ephesus Olusoji Fatunmbi ◽  
Samuel Segun Okoya
Keyword(s):  
Thermal Conductivity ◽  
Fluid Flow ◽  
Mixed Convection ◽  
Stagnation Point ◽  
Stretching Sheet ◽  
Ohmic Heating ◽  
Nonlinear Partial Differential Equations ◽  
Viscous Drag ◽  
Casson Nanofluid ◽  
Nonlinear Stretching

An analysis of nonlinear mixed convection transport of hydromagnetic Casson nanofluid over a nonlinear stretching sheet near a stagnation point is deliberated in this study. The flow is confined in a porous device in the presence of thermophoresis, Ohmic heating, non-uniform heat source with temperature-dependent thermal conductivity associated with haphazard motion of tiny particles. The transport equations are translated from nonlinear partial differential equations into ordinary ones via similarity transformation technique and subsequently tackled with shooting method coupled with Runge-Kutta Fehlberg algorithm. The significant contributions of the embedded parameters on the dimensionless quantities are graphically depicted and deliberated while the numerical results strongly agree with related published studies in the limiting conditions. It is found that a rise in the magnitude of Casson fluid parameter decelerates the fluid flow while enhancing the viscous drag and thermal profiles. The inclusion of the nonlinear convection term aids fluid flow whereas heat transfer reduces with growth in the thermophoresis and Brownian motion terms.

scholarly journals Investigation of thermal model effects on geothermal and oil reservoir well testing behavior during water and steam injection

2020 ◽  
Vol 75 ◽  
pp. 58
Author(s):  
Mahdi Abbasi ◽  
Mohammad Ahmadi ◽  
Alireza Kazemi ◽  
Mohammad Sharifi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Fluid Flow ◽  
Steam Injection ◽  
Model Parameters ◽  
Transfer Model ◽  
Diffusivity Coefficient ◽  
Reservoir Model ◽  
Type Curve ◽  
Water Steam

Global warming and reducing fossil fuel resources have increased the interest in using renewable resources such as geothermal energy. In this paper, in the first step, heat transfer equations have been presented for reservoir during water (steam) injection by considering heat loss to adjacent formations. According to radius of thermal front, the reservoir is partitioned into two regions with different fluid physical properties. The heat transfer model is coupled with a fluid flow model which is used to calculate the reservoir pressure or fluid flow rates. Then by calculating outer radius of heated region and using radial composite reservoir model, the fluid flow equations in porous media are solved. Using pressure derivative plot in regions with different thermal conductivity coefficients, a type curve plot is presented. The reservoir and adjacent formation thermal conductivity coefficients can be calculated by matching the observed pressure data on the thermal composite type curve. Additionally, the interference test in composite geothermal reservoir is discussed. In the composite reservoir model, parameters such as diffusivity coefficient, conductivity ratio and the distance to the radial discontinuity are considered. New type curves are provided to introduce the effect of diffusivity/conductivity contrast ratios on temperature behavior. Improving interpretations, and performing fast computations and fast sensitivity analysis are the benefits of the presented solutions.

scholarly journals Analysis of Magnetic Properties of Nano-Particles Due to a Magnetic Dipole in Micropolar Fluid Flow over a Stretching Sheet

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 170 ◽  
Author(s):  
Liaqat Ali ◽  
Xiaomin Liu ◽  
Bagh Ali ◽  
Saima Mujeed ◽  
Sohaib Abdal ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Nusselt Number ◽  
Fluid Flow ◽  
Differential Equations ◽  
Magnetic Dipole ◽  
Stretching Sheet ◽  
Nano Particles ◽  
Boundary Parameter ◽  
The Impact

This article explores the impact of a magnetic dipole on the heat transfer phenomena of different nano-particles Fe (ferromagnetic) and Fe3O4 (Ferrimagnetic) dispersed in a base fluid ( 60 % water + 40 % ethylene glycol) on micro-polar fluid flow over a stretching sheet. A magnetic dipole in the presence of the ferrities of nano-particles plays an important role in controlling the thermal and momentum boundary layers. The use of magnetic nano-particles is to control the flow and heat transfer process through an external magnetic field. The governing system of partial differential equations is transformed into a system of coupled nonlinear ordinary differential equations by using appropriate similarity variables, and the transformed equations are then solved numerically by using a variational finite element method. The impact of different physical parameters on the velocity, the temperature, the Nusselt number, and the skin friction coefficient is shown. The velocity profile decreases in the order Fe (ferromagnetic fluid) and Fe3O4 (ferrimagnetic fluid). Furthermore, it was observed that the Nusselt number is decreasing with the increasing values of boundary parameter ( δ ) , while there is controversy with respect to the increasing values of radiation parameter ( N ) . Additionally, it was observed that the ferromagnetic case gained maximum thermal conductivity, as compared to ferrimagnetic case. In the end, the convergence of the finite element solution was observed; the calculations were found by reducing the mesh size.

scholarly journals Mixed convection dissipative viscous fluid flow over a rotating cone by way of variable viscosity and thermal conductivity

2016 ◽  
Vol 6 ◽  
pp. 1126-1135 ◽  
Author(s):  
M.Y. Malik ◽  
Hamayun Jamil ◽  
T. Salahuddin ◽  
S. Bilal ◽  
K.U. Rehman ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Fluid Flow ◽  
Viscous Fluid ◽  
Mixed Convection ◽  
Variable Viscosity ◽  
Viscous Fluid Flow ◽  
Rotating Cone

Development Strategy of Insulation Macromolecular Composite Materials

2011 ◽  
Vol 391-392 ◽  
pp. 328-331
Author(s):  
Yong Peng Yu
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Development Strategy ◽  
Cooling System ◽  
High Thermal Conductivity ◽  
Nano Particles ◽  
Insulation Material ◽  
Foreign Companies ◽  
The Status ◽  
Insulation Systems

The status and progress of high pressure resistant insulation material at home and abroad were reviewed from aspects like high thermal conductivity, high temperature resistance, environ-mental protection and modification of nano-particles. High thermal conductivity insulation materials can improve the efficiency of cooling system and decrease the energy loss of electric machines. Some famous foreign companies keep ahead in this field. Current domestic high temperature resistant solvent less insulating varnish can only be used in small and medium sized generators instead of high voltage generators. Therefore this kind of material should be improved in either resin rich or resin less insulation systems.

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