Compressed Flow of Hybridized Nanofluid Entwined Between Two Rotating Plates Exposed to Radiation

2021 ◽  
Vol 10 (2) ◽  
pp. 186-199
Author(s):  
F. Almeida ◽  
P. Venkatesh ◽  
B. J. Gireesha ◽  
B. Nagaraja ◽  
K. M. Eshwarappa

The existing work unveils the mixed convection squeezed flow of MHD hybridized nanoliquid amid two plates of the channel that is rotating vertically depending upon time. The fluid is sucked/injected through the channel extremes. The hybrid nanofluid anticipated here is composed of Graphene oxide and Molybdenum disulphide with the hybrid base fluid comprised of water and ethylene glycol. The scrutiny is carried out in the presence of thermal radiation and heat source. The acquired equations are numerically computed with the aid of Runge Kutta Fehlberg 4–5th order method. The entropy behavior and Bejan number are examined utilizing graphs. The novelty of the work lies in perceiving which shape of nanoparticle has better tendency in escalating the heat transport and whip up the efficiency of the channel. The flow repercussion so obtained are emphasized for both hybrid and nano phase. On enlarging squeezing parameter, velocity escalates whereas for large values of rotating parameter velocity diminishes. The temperature is highest for blade structured and least for brick shaped nanoparticles. Heat generation/absorption parameter plays a crucial role in controlling the heating and cooling process. Higher value of this parameter augments the thermal profile. Bejan number is least for blade structured nanoparticles.

2019 ◽  
Vol 30 (3) ◽  
pp. 1457-1477 ◽  
Author(s):  
B.J. Gireesha ◽  
S. Sindhu

Purpose This paper aims to focus on the steady state flow of nanoliquid through microchannel with the aid of internal heat source and different shapes of nanoparticle. The influence of MoS2 and TiO2 particles of nano size on flow and thermal fields is examined. The governing equations are modelled and then solved numerically. The obtained physical model is nondimensionalized using dimensionless quantities. The nondimensional equations are treated with numerical scheme. The outcome of the current work is presented graphically. Diverse substantial quantities such as entropy generation, Bejan number and Nusselt number for distinct parameters are depicted through graphs. The result established that nanoparticle of blade shape acquires larger thermal conductivity. Entropy analysis is carried out to explore the impact of various parameters such as nanoparticle volume fraction, magnetic parameter, radiation parameter and heat source parameter. Design/methodology/approach The resultant boundary value problem is converted into initial value problem using shooting scheme. Then the flow model is resolved using Runge-Kutta-Fehlberg-Fourth-Fifth order technique. Findings It is emphasized that entropy generation for the fluid satisfies N(ζ)(TiO2−water) > N(ζ)(MoS2−water). In addition to this, it is emphasized that N(ζ)sphere > N(ζ)brick > N(ζ)cylinder > N(ζ)platelet > N(ζ)blade. Also, it is obtained that blade-shaped nanoparticle has higher thermal conductivity for both MoS2 and TiO2. Originality/value Shape effects on Molybdenum disulphide and TiO2 nanoparticle in a microchannel with heat source is examined. The analysis of entropy shows that N(ζ)(TiO2−water) > N(ζ)(MoS2−water).


Author(s):  
Saeed Dinarvand ◽  
Mohammadreza Nademi Rostami

In the present article, we intend to study quasi-analytically the unsteady three-dimensional squeezed flow of the magnetite–graphene oxide/water hybrid nanofluid inside a rotating channel with two horizontal and parallel sheets, in which the lower sheet is stationary, stretchable, and permeable, while the upper sheet is moving and impermeable. Our methodology is based on the single-phase Tiwari–Das hybrid nanofluid model considering nanoparticles and base fluid masses instead volume concentration of first and second nanoparticles. The dimensional partial differential equations are altered to a set of nondimensional ordinary differential equations with the help of similarity transformation method, which is then solved numerically using the bvp4c function from MATLAB. The governing similarity parameters are the empirical shape factor of nanoparticles, the suction parameter, the squeezing parameter, the rotation parameter, the Eckert number, and the Prandtl number. Results indicate that when the upper sheet faster moves toward the lower sheet, the profiles trend is opposite in comparison with when the upper sheet faster moves away from the lower one. On the one hand, the drastic thermal conductivity of the graphene oxide is a major reason to achieve maximum heat transfer rate enhancement of our working fluid. Finally, this study may be applicable in biomechanics, flow through arteries, food processing, polymer processing, lubrication, injection modeling, etc.


Fluids ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 138
Author(s):  
Ali Rehman ◽  
Zabidin Salleh

This paper analyses the two-dimensional unsteady and incompressible flow of a non-Newtonian hybrid nanofluid over a stretching surface. The nanofluid formulated in the present study is TiO2 + Ag + blood, and TiO2 + blood, where in this combination TiO2 + blood is the base fluid and TiO2 + Ag + blood represents the hybrid nanofluid. The aim of the present research work is to improve the heat transfer ratio because the heat transfer ratio of the hybrid nanofluid is higher than that of the base fluid. The novelty of the recent work is the approximate analytical analysis of the magnetohydrodynamics mixed non-Newtonian hybrid nanofluid over a stretching surface. This type of combination, where TiO2+blood is the base fluid and TiO2 + Ag + blood is the hybrid nanofluid, is studied for the first time in the literature. The fundamental partial differential equations are transformed to a set of nonlinear ordinary differential equations with the guide of some appropriate similarity transformations. The analytical approximate method, namely the optimal homotopy analysis method (OHAM), is used for the approximate analytical solution. The convergence of the OHAM for particular problems is also discussed. The impact of the magnetic parameter, dynamic viscosity parameter, stretching surface parameter and Prandtl number is interpreted through graphs. The skin friction coefficient and Nusselt number are explained in table form. The present work is found to be in very good agreement with those published earlier.


2021 ◽  
Vol 60 (3) ◽  
pp. 2947-2962
Author(s):  
T. Armaghani ◽  
M.S. Sadeghi ◽  
A.M. Rashad ◽  
M.A. Mansour ◽  
Ali J. Chamkha ◽  
...  

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fazle Mabood ◽  
Anum Shafiq ◽  
Waqar Ahmed Khan ◽  
Irfan Anjum Badruddin

Purpose This study aims to investigate the irreversibility associated with the Fe3O4–Co/kerosene hybrid-nanofluid past a wedge with nonlinear radiation and heat source. Design/methodology/approach This study reports the numerical analysis of the hybrid nanofluid model under the implications of the heat source and magnetic field over a static and moving wedge with slips. The second law of thermodynamics is applied with nonlinear thermal radiation. The system that comprises differential equations of partial derivatives is remodeled into the system of differential equations via similarity transformations and then solved through the Runge–Kutta–Fehlberg with shooting technique. The physical parameters, which emerges from the derived system, are discussed in graphical formats. Excellent proficiency in the numerical process is analyzed by comparing the results with available literature in limiting scenarios. Findings The significant outcomes of the current investigation are that the velocity field uplifts for higher velocity slip and magnetic strength. Further, the heat transfer rate is reduced with the incremental values of the Eckert number, while it uplifts with thermal slip and radiation parameters. An increase in Brinkmann’s number uplifts the entropy generation rate, while that peters out the Bejan number. The results of this study are of importance involving in the assessment of the effect of some important design parameters on heat transfer and, consequently, on the optimization of industrial processes. Originality/value This study is original work that reports the hybrid nanofluid model of Fe3O4–Co/kerosene.


2019 ◽  
Vol 6 (2) ◽  
pp. a1-a7
Author(s):  
N. V. Lishchenko ◽  
V. P. Larshin ◽  
H. Krachunov

A study of a simplified mathematical model for determining the grinding temperature is performed. According to the obtained results, the equations of this model differ slightly from the corresponding more exact solution of the one-dimensional differential equation of heat conduction under the boundary conditions of the second kind. The model under study is represented by a system of two equations that describe the grinding temperature at the heating and cooling stages without the use of forced cooling. The scope of the studied model corresponds to the modern technological operations of grinding on CNC machines for conditions where the numerical value of the Peclet number is more than 4. This, in turn, corresponds to the Jaeger criterion for the so-called fast-moving heat source, for which the operation parameter of the workpiece velocity may be equivalently (in temperature) replaced by the action time of the heat source. This makes it possible to use a simpler solution of the one-dimensional differential equation of heat conduction at the boundary conditions of the second kind (one-dimensional analytical model) instead of a similar solution of the two-dimensional one with a slight deviation of the grinding temperature calculation result. It is established that the proposed simplified mathematical expression for determining the grinding temperature differs from the more accurate one-dimensional analytical solution by no more than 11 % and 15 % at the stages of heating and cooling, respectively. Comparison of the data on the grinding temperature change according to the conventional and developed equations has shown that these equations are close and have two points of coincidence: on the surface and at the depth of approximately threefold decrease in temperature. It is also established that the nature of the ratio between the scales of change of the Peclet number 0.09 and 9 and the grinding temperature depth 1 and 10 is of 100 to 10. Additionally, another unusual mechanism is revealed for both compared equations: a higher temperature at the surface is accompanied by a lower temperature at the depth. Keywords: grinding temperature, heating stage, cooling stage, dimensionless temperature, temperature model.


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