Evaluation of Heat Irreversibility in a Thin Film Flow of Couple Stress Fluid on a Moving Belt

This article addresses the inherent heat irreversibility in the flow of a couple stress thin film along a moving vertical belt subjected to free and adiabatic surface. Mathematical analysis for the fluid-governing-equations is performed in detail. For maximum thermal performance and efficiency, the present analysis follows the second law of thermodynamics approach for the evaluation of entropy generation rate in the moving film. With this thermodynamic process, the interconnectivity between variables responsible for energy wastage is accounted for in the thermo-fluid equipment. Results of the analysis revealed the fluid properties that contribute more to energy loss and how the exergy of the system can be restored.

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Thin Film Flow of Couple Stress Magneto-Hydrodynamics Nanofluid with Convective Heat over an Inclined Exponentially Rotating Stretched Surface

Coatings ◽

10.3390/coatings10040338 ◽

2020 ◽

Vol 10 (4) ◽

pp. 338 ◽

Cited By ~ 2

Author(s):

Asifa Tassaddiq ◽

Ibni Amin ◽

Meshal Shutaywi ◽

Zahir Shah ◽

Farhad Ali ◽

...

Keyword(s):

Thin Film ◽

Brownian Motion ◽

Differential Equations ◽

Prandtl Number ◽

Ordinary Differential Equations ◽

Couple Stress ◽

Magnetic Parameter ◽

Film Flow ◽

Thin Film Flow ◽

Brownian Motion Parameter

In this article a couple stress magneto-hydrodynamic (MHD) nanofluid thin film flow over an exponential stretching sheet with joule heating and viscous dissipation is considered. Similarity transformations were used to obtain a non-linear coupled system of ordinary differential equations (ODEs) from a system of constitutive partial differential equations (PDEs). The system of ordinary differential equations of couple stress magneto-hydrodynamic (MHD) nanofluid flow was solved using the well-known Homotopy Analysis Method (HAM). Nusselt and Sherwood numbers were demonstrated in dimensionless forms. At zero Prandtl number the velocity profile was analytically described. Furthermore, the impact of different parameters over different state variables are presented with the help of graphs. Dimensionless numbers like magnetic parameter M, Brownian motion parameter Nb, Prandtl number Pr, thermophoretic parameter Nt, Schmidt number Sc, and rotation parameter S were analyzed over the velocity, temperature, and concentration profiles. It was observed that the magnetic parameter M increases the axial, radial, drainage, and induced profiles. It was also apparent that Nu reduces with greater values of Pr. On increasing values of the Brownian motion parameter the concentration profile declines, while the thermophoresis parameter increases.

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Thin-Film Flow Over a Rotating Plate: An Assessment of the Suitability of VOF and Eulerian Thin-Film Methods for the Numerical Simulation of Isothermal Thin-Film Flows

Volume 5C: Heat Transfer ◽

10.1115/gt2015-43506 ◽

2015 ◽

Cited By ~ 1

Author(s):

B. Kakimpa ◽

H. P. Morvan ◽

S. Hibberd

Keyword(s):

Thin Film ◽

Film Thickness ◽

Film Flow ◽

Computational Cost ◽

Inlet Temperature ◽

Thin Film Flow ◽

Vof Model ◽

Fluid Properties ◽

Thickness Variations ◽

Rotating Plate

An isothermal thin-film flow over a rotating plate has been simulated using the depth-averaged Eulerian Thin-Film modelling (ETFM) approach. The model setup is based on published experimental and numerical Volume of Fluid (VOF) CFD studies of the same problem to allow for model validation. A range of controlled film inlet heights and mass flow rates are explored together with varied plate rotational speeds ranging from a stationary plate (50rpm) to 200 rpm. While the VOF model has previously been shown to accurately reproduce film thickness, the Eulerian thin-film model is shown to provide predictions of comparable accuracy at a much lower computational cost. The model is also shown to be able to reproduce the film solution’s sensitivity to variations in fluid properties due to changes in inlet temperature. A full 3D domain has been used in this study and the ETFM model is also shown to be able to reproduce azimuthal film thickness variations and surface features similar to those previously observed in experiments.

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Thin film flow of an unsteady Maxwell fluid over a shrinking/stretching sheet with variable fluid properties

International Journal of Numerical Methods for Heat &amp Fluid Flow ◽

10.1108/hff-12-2017-0498 ◽

2018 ◽

Vol 28 (7) ◽

pp. 1596-1612 ◽

Cited By ~ 5

Author(s):

N. Faraz ◽

Y. Khan

Keyword(s):

Thin Film ◽

Differential Equation ◽

Boundary Layer ◽

Partial Differential Equation ◽

Stretching Sheet ◽

Film Flow ◽

Maxwell Fluid ◽

Thin Film Flow ◽

Content Type ◽

Fluid Properties

Purpose This paper aims to explore the variable properties of a flow inside the thin film of a unsteady Maxwell fluid and to analyze the effects of shrinking and stretching sheet. Design/methodology/approach The governing mathematical model has been developed by considering the boundary layer limitations. As a result of boundary layer assumption, a nonlinear partial differential equation is obtained. Later on, similarity transformations have been adopted to convert partial differential equation into an ordinary differential equation. A well-known homotopy analysis method is implemented to solve the problem. MATHEMATICA software has been used to visualize the flow behavior. Findings It is observed that variable viscosity does not have a significant effect on velocity field and temperature distribution either in shrinking or stretching case. It is noticed that Maxwell parameter has no dramatic effect on the flow of thin liquid fluid. It has been seen that heat flow increases by increasing the conductivity with temperature in both cases (shrinking/stretching). As a result, fluid temperature goes down when than delta = 0.05 than delta = 0.2. Originality/value To the best of authors’ knowledge, nobody has conducted earlier thin film flow of unsteady Maxwell fluid with variable fluid properties and comparison of shrinking and stretching sheet.

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