Convection Flow of MHD Couple Stress Fluid in Vertical Microchannel with Entropy Generation

2020

HFF

Purpose Microfluidics is one of the extensive elaborated technologies in thermal and engineering fields due to its wide range of applications, such as micro heat exchangers, micro mixture and microchannel heat sinks, which is used to develop a large number of microscopic devices and systems. Enhancement of thermal energy using verity of nanoliquids is one of the challenges in these applications of microfluidics. Therefore, using single wall carbon nanotubes for enhancement of thermal energy in microchannel is the main purpose of this study. Hall effect of natural convection flow in a vertical channel with slip and temperature jump condition is considered. The impacts of radiative heat flux, uniform heat source/sink, viscous dissipation and joule heating are also taken into account. Design/methodology/approach Suitable non-dimension variables are applied to the governing equations to reduce the system into ordinary differential equations. The reduced nonlinear system is then solved numerically using Runge–Kutta–Fehlberg fourth–fifth-order method along with shooting technique. The impact of different pertinent parameters on numerical solutions of primary velocity, secondary velocity, temperature, entropy generation and Bejan number is comprehensively discussed in detail. Also, the obtained numerical results are compared with existing one which perfectly found to be in good agreement. Findings It is established that, with the aspects of Joule heating, viscous dissipation, radiative heat flux and uniform heat source/sink, the production in the entropy can be improved. Further, it is found that the increasing ratio of wall ambient temperature difference and nanoparticle volume fraction leads to enhance the entropy generation. The same effect reverses with increasing values of fluid wall interaction parameter (FWIP) and rare faction. The irreversibility ratio enhances with larger values of nanoparticle volume fraction and decelerates with increment values of FWIP. Originality/value The impact of single wall carbon nanoliquid in a vertical channel flow by using radiative heat flux, heat source/sink, joule heating and viscous dissipation is first time investigated. Further, the influence of Hall current is explored in detail.

Section: Hall Effect Of Natural Convection Flowmentioning

confidence: 99%

Second law analysis on Hall effect of natural convection flow through vertical channel in the presence of uniform heat source/sink

Roja

2020

HFF

“…They have noticed that the impact of diffusivity is dominant in a couple stress fluid flow. In a vertical channel, an electrically conducting couple stress fluid flow subjected to the fluid friction irreversibility has been studied by Opanuga et al 14 Including, they have studied the impact of various flow parameters such as effective temperature ratio, rarefaction, and FWI parameter on the fluid motion, thermal field, entropy, and Bejan number in detail through graphs. Many authors have studied the flow and heat transfer analysis in different aspects by using various effects 15–27 …”

Section: Introductionmentioning

confidence: 99%

Flow and heat transfer analysis of MHD third‐grade fluid flow through a vertical microchannel subjected to entropy generation

Roja¹,

2022

Heat Trans

This paper analyses the generation of entropy in an electrically conducting third‐grade fluid through a vertical channel considering the variable thermal conductivity. Aspects of radiation, viscous dissipation, porous medium, Joule heating, convective boundary condition, and heat generation are studied. Nonlinear systems of ordinary differential equations are obtained via applying suitable dimensionless variables. After that, the system is solved with the aid of using the Runge–Kutta–Fehlberg method. The numerical solutions are used to characterize the irreversibility and irreversibility ratio. It is established that the entropy is enhanced with accelerating estimations of the third‐grade material parameter, Brinkman number, magnetism, Biot number, porous parameter, and the impact is decelerated with elevating values of the radiation. The rate of heat transfer is higher for the Brinkman number, and a similar impact on drag force is noticed for magnetic and Grashof numbers. All the parameters on flow, temperature, fluid irreversibility and irreversibility ratio are discussed through graphical illustration.

“…In a uniformly heated microchannel, the entropy generation analysis under the impact of Darcy porous medium has been depicted by Abbassi. 8 The combined effects of various physical parameters such as Prandtl number, Reynolds number, and Brinkmann number in a parallel plate channel subjected to irreversibility analysis have been displayed by Erbay et al 9 In a vertical microchannel, the irreversibility investigation in an electrically conducting couple stress fluid under the effect of magnetism, Joule heating, and viscous dissipation has been discussed by Abiodun et al 10 By utilizing generators of a longitudinal vortex, the entropy generation in a channel has been depicted by Ebrahimi et al 11 Several investigations have been done on irreversibility analysis in a channel with different geometries. [12][13][14][15][16][17][18][19][20] The impact of Hall current on natural convection flow in a microchannel via analyzing irreversibility has been represented by Agboola et al 21 In their study, the impact of WATDR, Hall current, and fluid wall interaction parameter (FWIP) on fluid motion, temperature, irreversibility, and irreversibility ratio has been studied.…”

Section: Introductionmentioning

confidence: 99%

“…Including, it is also important from the perspective of industrial applications, such as the refreshing of metallic plates in a shower, extrusion of polymer liquids, and it has increased carrying fluid flow through the thin film 29,30 . Regarding this, the analysis of couple stress fluid between two parallel channels under the effects of magnetism, Joule heating, and the convective boundary has been discussed by Kareem et al 31 The couple stress fluid flow between parallel channels by utilizing Adomin decomposition method has been reported by Adesanya et al 32 In an MHD couple, stress fluid through a vertical microchannel subjected to the analysis of irreversibility has been displayed by Opanuga et al 33 They have observed the different parameters, such as rarefaction, the ratio of effective temperature, and FWIP on fluid motion, thermal field, irreversibility, and irreversibility ratio in detail through graphs. In a similar manner, many researchers have conducted their research on flow and heat transfer analysis in different channels in different aspects of the physical model 34‐41 …”

Section: Introductionmentioning

confidence: 99%

Hall effects on MHD couple stress fluid flow through a vertical microchannel subjected to heat generation: A numerical study

Roja

2020

Heat Trans

The present study analyzes the irreversibility in an electrically conducting couple stress fluid between two vertical channel plates with the aspects of exponential space and temperature-dependent, radiative heat flux, heat generation, and Joule heating. A reduced system of the governing equations is obtained via applying suitable nondimensional variables. To determine the solutions of velocity, thermal field, irreversibility, and irreversibility ratio, the Runge-Kutta-Fehlberg method along with the shooting technique has been employed. The various pertinent parameters that are involved in the problem have been discussed in detail through graphs. The results show that the entropy production can improve with the viscous dissipation, Joule heating, exponential space and temperature-dependent, and radiative heat flux. Furthermore, it is clear that the entropy enhances with wall ambient temperature difference, radiation parameter, and the effect is reversed with higher estimations of the fluid wall interaction parameter, couple stress parameter, and rarefaction. The present numerical results are compared with the existing results that are in good agreement.