scholarly journals A modified Fourier-Fick analysis for modeling non-Newtonian mixed convective flow considering heat generation

2020 ◽  
Vol 24 (2 Part B) ◽  
pp. 1381-1387
Author(s):  
Muhammad Anwar ◽  
Muhammad Saqlain ◽  
Muhammad Gulzar ◽  
Muhammad Waqas
Keyword(s):  
Convective Flow ◽  
Linear Analysis ◽  
Coupled Equations ◽  
Buoyancy Forces ◽  
Non Linear ◽  
Dimensionless Variables ◽  
Mixed Convective Flow ◽  
Non Linear System ◽  
Variable Conductivity ◽  
Comprehensive Discussion

Homotopic solutions for Jeffrey material in frames of buoyancy forces are constructed in this research. The improved Fourier-Fick laws are considered for formulation. In addition, variable liquid aspects (thermal conductivity, mass diffusiv?ity) along with heat source are accounted. Prandtl?s boundary-layer idea is utilized to model the problem. Involvement of similarity variables resulted into non-linear system of coupled equations. The well-known homotopic scheme is employed for non-linear analysis. Besides, a comprehensive discussion is reported for arising dimensionless variables vs. significant profiles. Our results indicate a rise in thermal and solutal fields when variable conductivity and mass diffusivity parameters are increased.

Entropy Optimization in Nonlinear Mixed Convective Flow of Nanomaterials Through Porous Space

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tasawar Hayat ◽  
Ikram Ullah ◽  
Ahmad Alsaedi ◽  
Shaher Momani
Keyword(s):  
Convective Flow ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Porous Space ◽  
Arrhenius Activation Energy ◽  
Suction Parameter ◽  
Electrically Conducting ◽  
Entropy Optimization ◽  
Dimensionless Variables ◽  
Mixed Convective Flow

Abstract Our intention in this article is to investigate entropy optimization in nonlinear mixed convective unsteady magnetohydrodynamic flow of nanomaterials in porous space. An exponentially stretched sheet creates the liquid flow. Nanomaterial is considered electrically conducting. The concentration and energy expressions comprise viscous dissipation, Joule heating, thermophoresis and Brownian motion aspects. Arrhenius activation energy is considered. Computation of entropy generation based upon the second law of thermodynamics is made. Nonlinear partial expressions are obtained via suitable dimensionless variables. Resultant expressions are tackled by the OHAM technique. Features of numerous variables on entropy, temperature, velocity and concentration are graphically visualized. Skin friction and the temperature gradient at the surface are also elaborated. Comparative analysis is deliberated in tabulated form to validate the previously published outcomes. Velocity is reduced significantly via the suction parameter. The entropy rate increases for higher values of Brinkman, Biot and Hartmann numbers.

scholarly journals Non-Linear Analysis of Vibrations of Non-Linear System Subjected to Multi-Excitation Forces via a Non-Linear Absorber

2012 ◽  
Vol 03 (01) ◽  
pp. 64-72 ◽  
Author(s):  
Taha H. El-Ghareeb ◽  
Yaser S. Hamed ◽  
Mohamed S. Abd Elkader
Keyword(s):  
Linear System ◽  
Linear Analysis ◽  
Non Linear ◽  
Non Linear System

scholarly journals Hydrodynamic Analysis of Laminar Mixed Convective Flow of Ag-TiO2-Water Hybrid Nanofluid in a Horizontal Annulus

CFD letters ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 45-57
Author(s):  
Badr Ali Bzya Albeshri ◽  
Nazrul Islam ◽  
Ahmad Yahya Bokhary ◽  
Amjad Ali Pasha
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Convective Flow ◽  
Base Fluid ◽  
Entrance Region ◽  
Heat Transfer Fluid ◽  
Hybrid Nanofluid ◽  
Hydrodynamic Behavior ◽  
Buoyancy Forces ◽  
Mixed Convective Flow

Nanofluids occupy a large place in many fields of technology due its improved heat transfer and pressure drop characteristics. Very recently, a new type of nanofluid, known as hybrid nanofluid, which consists of a mixture of two different nanoparticles suspended in the base fluid has been found to be the most emerging heat transfer fluid. It is well also established that entrance region effect enhances heat transfer rate. The present study deals with numerical investigations of the hydrodynamic behavior of the laminar mixed convective flow of a hybrid nanofluid in the entrance region of a horizontal annulus. A thermal boundary condition of uniform heat flux at the inner wall and an adiabatic outer wall is selected. The SIMPLER numerical algorithm is adopted in the present study. The hybrid nanofluid consists of water as base fluid and Ag-TiO2 as nanoparticles. The ratio of Ag to TiO2 is maintained as 1:3. The objective of the current study is mainly to analyze the hydrodynamic behavior hybrid nanofluid in the entrance region. The investigation reveals that the effect of the secondary flow due to the buoyancy forces is more intense in the upper part of the annular cross-section. It increases throughout the cross-section until its intensity reaches a maximum and then it becomes weak far downstream. The development of axial flow and temperature field is strongly influenced by the buoyancy forces.

A Numerical Study of Laminar and Turbulent Mixed Convective Flow Over a Vertical Isothermal Plate

2010 ◽  
Author(s):  
Patrick H. Oosthuizen
Keyword(s):  
Heat Transfer ◽  
Prandtl Number ◽  
Heat Transfer Rate ◽  
Convective Flow ◽  
Transfer Rate ◽  
Free Stream ◽  
Heated Surface ◽  
Buoyancy Forces ◽  
The Mean ◽  
Mixed Convective Flow

Mixed (or combined) convective flow is flow with heat transfer in which there is a forced flow but in which the buoyancy forces that arise due to temperature variations in the flow have a significant effect on the flow and therefore on the heat transfer rate. In such flows the buoyancy forces can also have a very significant influence on the conditions under which transition from laminar to turbulent flow occurs. In the present study this effect of the buoyancy forces on the conditions under which transition occurs have been studied for the particular case of flow in the vertically upward direction over a heated vertical flat plane surface that is maintained at a uniform temperature that is higher than the temperature of the undisturbed fluid flow, i.e., attention has been restricted to assisting (or aiding) mixed convective flow. The flow has been assumed to be steady and it has also been assumed that the fluid properties are constant except for the density change with temperature which gives rise to the buoyancy forces, this having been treated by using the Boussinesq approach. The solution has been obtained by numerically solving the governing equations subject to the boundary conditions using the commercial cfd solver, FLUENT. The k-epsilon turbulence model with full account being taken of the buoyancy forces has been used in obtaining the solutions. The mean heat transfer rate from the surface expressed in terms of the mean Nusselt number depends on the Reynolds number based on the free-stream forced velocity and the length of the heated surface, on the Rayleigh number based on the length of the heated surface and the overall surface to free-stream temperature difference, and on the Prandtl number. Results have only been obtained for a Prandtl number of 0.74. Solutions have been obtained for a series of increasing Rayleigh numbers between 105 and 1012 for a series of Reynolds numbers between approximately 1 and 107.

Determination of Concrete Cube Strength from Used Samples / Určení Krychelné Pevnosti Betonu U Použitých Zkušebních Trámců

2012 ◽  
Vol 12 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Oldřich Sucharda ◽  
David Mikolášek ◽  
Jiří Brožovský
Keyword(s):  
Compressive Strength ◽  
Concrete Beams ◽  
Linear Analysis ◽  
Bending Tests ◽  
Cube Strength ◽  
Non Linear ◽  
Compressive Strength Of Concrete ◽  
Concrete Cube

Abstract This paper deals with the determination of compressive strength of concrete. Cubes, cylinders and re-used test beams were tested. The concrete beams were first subjected to three-point or fourpoint bending tests and then used for determination of the compressive strength of concrete. Some concrete beams were reinforced, while others had no reinforcement. Accuracy of the experiments and calculations was verified in a non-linear analysis.

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