Couple stress fluid flow with variable properties: A second law analysis

AbstractThe study of oscillating flow of a Couple Stress fluid past a permeable sphere is considered. Analytical solution for the flow field in terms of stream function is obtained using modified Bessel functions. The formula for Drag acting on the sphere due external flow is evaluated. Pressure field for the flow region past and inside the sphere is obtained. Effects of physical parameters like couple stress parameter, permeability, frequency and geometric parameters on the drag due to internal and external flows are represented graphically. It is observed that the drag for viscous fluid flow will be less than the case of couple-stress fluid flow and hence couple stress fluids offer resistance for flow.

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Second-law analysis of fluid flow over an isothermal moving wedge

Alexandria Engineering Journal ◽

10.1016/j.aej.2013.11.011 ◽

2014 ◽

Vol 53 (1) ◽

pp. 1-9 ◽

Cited By ~ 17

Author(s):

F. Hedayati ◽

A. Malvandi ◽

D.D. Ganji

Keyword(s):

Fluid Flow ◽

Second Law ◽

Second Law Analysis ◽

Moving Wedge

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Second Law Analysis of Magneto-Micropolar Fluid Flow Between Parallel Porous Plates

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4039633 ◽

2018 ◽

Vol 10 (4) ◽

Cited By ~ 1

Author(s):

Abbas Kosarineia ◽

Sajad Sharhani

Keyword(s):

Magnetic Field ◽

Reynolds Number ◽

Fluid Flow ◽

Entropy Generation ◽

Hartmann Number ◽

Second Law ◽

Brinkman Number ◽

Viscosity Parameter ◽

Micropolar Fluid Flow ◽

Second Law Analysis

In this study, the influence of the applied magnetic field is investigated for magneto-micropolar fluid flow through an inclined channel of parallel porous plates with constant pressure gradient. The lower plate is maintained at constant temperature and the upper plate at a constant heat flux. The governing motion and energy equations are coupled while the effect of the applied magnetic field is taken into account, adding complexity to the already highly correlated set of differential equations. The governing equations are solved numerically by explicit Runge–Kutta. The velocity, microrotation, and temperature results are used to evaluate second law analysis. The effects of characteristic and dominate parameters such as Brinkman number, Hartmann Number, Reynolds number, and micropolar viscosity parameter are discussed on velocity, temperature, microrotation, entropy generation, and Bejan number in different diagrams. The results depicted that the entropy generation number rises with the increase in Brinkman number and decays with the increase in Hartmann Number, Reynolds number, and micropolar viscosity parameter. The application of the magnetic field induces resistive force acting in the opposite direction of the flow, thus causing its deceleration. Moreover, the presence of magnetic field tends to increase the contribution of fluid friction entropy generation to the overall entropy generation; in other words, the irreversibilities caused by heat transfer reduced. Therefore, to minimize entropy, Brinkman number and Hartmann Number need to be controlled.

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