Thermophoretic particle deposition in time-dependent flow of hybrid nanofluid over rotating and vertically upward/ downward moving disk
TL;DR: In this article, the authors examined the deposition of thermophoretic particles in the flow of hybrid nanofluid suspended by ferrite nanoparticles past an expansion/contraction moving disk with rotation.
About: This article is published in Surfaces and Interfaces.The article was published on 2021-02-01. It has received 97 citations till now. The article focuses on the topics: Nanofluid & Particle deposition.
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16 Apr 2021
TL;DR: In this paper, the steady Marangoni driven boundary layer flow, heat and mass transfer characteristics of a nanofluid were studied using the Runge-Kutta-Fehlberg fourth-fifth order (RKF-45) method.
Abstract: The flow and heat transfer of non-Newtonian nanofluids has an extensive range of applications in oceanography, the cooling of metallic plates, melt-spinning, the movement of biological fluids, heat exchangers technology, coating and suspensions. In view of these applications, we studied the steady Marangoni driven boundary layer flow, heat and mass transfer characteristics of a nanofluid. A non-Newtonian second-grade liquid model is used to deliberate the effect of activation energy on the chemically reactive non-Newtonian nanofluid. By applying suitable similarity transformations, the system of governing equations is transformed into a set of ordinary differential equations. These reduced equations are tackled numerically using the Runge–Kutta–Fehlberg fourth-fifth order (RKF-45) method. The velocity, concentration, thermal fields and rate of heat transfer are explored for the embedded non-dimensional parameters graphically. Our results revealed that the escalating values of the Marangoni number improve the velocity gradient and reduce the heat transfer. As the values of the porosity parameter increase, the velocity gradient is reduced and the heat transfer is improved. Finally, the Nusselt number is found to decline as the porosity parameter increases.
163 citations
Cites background from "Thermophoretic particle deposition ..."
...[10] studied the stream of liquid with a hybrid nanoparticles suspension over a moving disk with spin by considering particle deposition....
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TL;DR: In this article, the thermal properties of AA7072-AA7075/water-based hybrid nanofluid over a curved stretching sheet using non-Fourier heat flux model were analyzed.
142 citations
TL;DR: In this article, a comparative study on flow of two diverse combinations of hybrid nanofluids, namely MnZnFe2O4−NiZn Fe4−C10H22 and Cu−Al2O3−C 10H22, was conducted to investigate the thermal and mass transfer in hybrid nanoliquid flow over a stretching cylinder.
Abstract: Nanofluids manage heat in the internal combustion of the engines or machines by avoiding corrosion in the cooling system as well as assist in eradicating the engine’s waste heat. Hence, they are used as coolants in many automotive industries. Inspired by these applications, the thermal and mass transfer in hybrid nanoliquid flow over a stretching cylinder on taking account of magnetic dipole is studied in this investigation. Here, we have done a comparative study on flow of two diverse combinations of hybrid nanofluids, namely MnZnFe2O4−NiZnFe2O4−C10H22 and Cu−Al2O3−C10H22. The modelled equation for the assumed flow is converted to ODEs by opting appropriate similarity variables. These ODEs are solved by utilizing the Runge–Kutta Fehlberg fourth-fifth order (RKF-45) method by adopting shooting technique. Physical clarification of relevant parameters for non-dimensional discrete flow fields are discussed briefly by using graphs. Also, skin friction, Sherwood and Nusselt numbers are deliberated with the assistance of graphs. Results reveal that, the upsurge in ferromagnetic interaction parameter declines the velocity in both fluids but converse trend is detected in temperature and concentration of the liquids. The heightening of ferromagnetic interaction parameter declines the rate of heat and mass transfer.
96 citations
TL;DR: In this article, the impact of dispersion of nanoparticle CuO in base liquid water on the performance of flow, thermal conductivity and mass transfer using KKL model in the presence of Cattaneo-Christov heat flux and activation energy is deliberated.
Abstract: The objective of the current paper is to study the two-dimensional, incompressible nanofluid flow over a curved stretching sheet coiled in a circle. Further, the impact of dispersion of nanoparticle CuO in base liquid water on the performance of flow, thermal conductivity and mass transfer using KKL model in the presence of Cattaneo-Christov heat flux and activation energy is deliberated. A curvilinear coordinate system is used to develop the mathematical model describing the flow phenomena in the form of partial differential equations. Further, by means of apt similarity transformations the governing boundary value problems are reduced to ordinary differential equations. Mathematical computations are simplified using Runge-Kutta-Fehlberg-45(RKF-45) process by adopting shooting method. Graphical illustrations of velocity, temperature, concentration gradients for various pertinent parameters are presented. The result reveals that, the heightening of porosity parameter heightens the thermal gradient but converse trend is depicted in velocity gradient. The enhancing values of Schmidt number and chemical reaction rate parameter declines concentration gradient whereas converse trend is depicted for upsurge in activation energy parameter.
85 citations
TL;DR: In this article, the impact of magnetic effect on the Casson nanoliquid flow over a curved stretching sheet with the influence of chemical reaction was explored and the heat and mass transfere...
Abstract: The current article explores the impact of magnetic effect on the Casson nanoliquid flow over a curved stretching sheet with the influence of chemical reaction. Further, the heat and mass transfere...
76 citations
References
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TL;DR: In this paper, a laser-Doppler velocimeter (LDV) study of velocity profiles in the laminar boundary layer adjacent to a heated flat plate revealed that the seed particles used for the LDV measurements were driven away from the plate surface by thermophoretic forces, causing a particle free region within the boundary layer of approximately one half the boundary-layer thickness.
Abstract: A laser-Doppler velocimeter (LDV) study of velocity profiles in the laminar boundary layer adjacent to a heated flat plate revealed that the seed particles used for the LDV measurements were driven away from the plate surface by thermophoretic forces, causing a particle-free region within the boundary layer of approximately one half the boundary-layer thickness. Measurements of the thickness of this region were compared with particle trajectories calculated according to several theories for the thermophoretic force. It was found that the theory of Brock, with an improved value for the thermal slip coefficient, gave the best agreement with experiment for low Knudsen numbers, λ/R = O(10−1), where λ is the mean free path and R the particle radius.Data obtained by other experimenters over a wider range of Knudsen numbers are compared, and a fitting formula for the thermophoretic force useful over the entire range 0 [les ] λ/R [les ] ∞ is proposed which agrees within 20% or less with the majority of the available data.
1,372 citations
01 Sep 1985
TL;DR: In this article, it was shown that the particle flux to the boundary is proportional to the total heat flux from the boundary to the moving fluid, and that the relation between C 1 / C 0 and T 1 / T 0 is approximately the same for all flow systems.
Abstract: The rate at which particles carried in a flowing gas are deposited on a cold surface by thermophoretic movement is studied theoretically. Some exact deductions from the coupled equations for the temperature ( T ) and particle concentration ( C ) in the moving fluid show that, in cases in which the particles come from a region in which T and C are uniform with values T 0 and C 0 , there are strong constraints on the possible values of C / C 0 at a point at which T / T 0 is known. This suggests the hypotheses that C / C 0 is approximately uniform (with value C 1 / C 0 say) over a cold isothermal boundary (at temperature T 1 ), in which event the total particle flux to the boundary is proportional to the total heat flux to the boundary, and that the relation between C 1 / C 0 and T 1 / T 0 is approximately the same for all flow systems. These hypotheses are tested against the available numerical results for a number of steady flow systems, four of them relating to cold bodies in a uniform stream of gas and two relating to flow in a circular tube downstream from a sudden drop in wall temperature, and are found to represent the exact results with adequate accuracy except when both T 1 / T 0 and the thermophoretic coefficient are small. We thus have a means of estimating the total rate of deposition on a cold isothermal boundary from a knowledge of the total heat flux to the boundary in cases in which computation of the distributions of temperature and particle concentration in the fluid is not feasible, although further tests of the hypotheses are desirable.
319 citations
TL;DR: The presented approach serves to understand the stabilizing/destabilizing effects of nanofluids as compared to the standard base fluids in terms of stability of viscous/inviscid and temporal/spatial senses.
168 citations
TL;DR: In this paper, the steady MHD laminar flow of an electrically conducting fluid on a radially stretchable rotating disk in the presence of a uniform vertical magnetic field is investigated.
146 citations
TL;DR: In this paper, the development of the fluid flow and resultant heat transfer caused by a rotating disk moving vertically upward or downward during an unsteady flow motion is studied, and it is observed that the upward and downward motion of the disk exerts an effect similar to that of the injection/suction through the wall, albeit with observable differences.
Abstract: The object of this study is the development of the fluid flow and resultant heat transfer caused by a rotating disk moving vertically upward or downward during an unsteady flow motion. The problem is formulated such that the similarity equations governing the physical phenomenon eventually reduced to those reported in the traditional viscous pumping study of von Karman for a vertically motionless but still rotating disk. The non-rotating disk with the upward or downward motion leads to the formation of a two-dimensional flow over the disk. Otherwise, the rotation and vertical action of the disk sets up a three-dimensional flow over the surface. It is observed that the upward and downward motion of the disk exerts an effect similar to that of the injection/suction through the wall, albeit with observable differences. Moreover, the viscous pumping is found to be a jet-like radial velocity as the disk moves upward fast. Although the downward movement of the disk suppresses the velocity field, a growth in the boundary layer thickness is anticipated, contrary to the traditional wall suction. The temperature field is shown to be highly dependent on the form of the wall temperature, which is maintained at a time-varying function. Moreover, the impact of the vertical wall movement is observed to be overwhelmed by high disk rotations.
99 citations