MD. Shamshuddin^{1, *}, C. Balarama Krishna²

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.3, pp. 207-231, 2019, DOI:10.32604/fdmp.2019.00449

Abstract Mathematical model for an unsteady, incompressible, electrically conducting micropolar fluid past a vertical plate through porous medium with constant plate velocity has been investigated in the present study. Heat absorption, Joulian dissipation, and firstorder chemical reaction is also considered. Under the assumption of low Reynolds number, the governing transport equations are rendered into non-dimensional form and the transformed first order differential equations are solved by employing an efficient finite element method. Influence of various flow parameters on linear velocity, microrotation velocity, temperature, and concentration are presented graphically. The effects of heat absorption and chemical reaction rate decelerate the flow is… More >

M. Krishna Prasad¹, G. Manpreet Kaur¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.2, pp. 107-125, 2017, DOI:10.3970/fdmp.2017.013.107

Abstract The slow steady rotation of a micropolar fluid spheroid whose shape deviates slightly from that of a sphere in concentric spheroidal container filled with Newtonian viscous fluid is studied analytically. The boundary conditions used are the continuity of velocity and stress components, and spin vorticity relation. The torque and wall correction factor exerted on the micropolar fluid spheroid is obtained. The dependence of wall correction factor on the micropolarity parameter, spin parameter, viscosity ratio and deformation parameter is studied numerically and its variation is presented graphically. In the limiting cases, the torque acting on solid spheroid in spheroidal container and… More >

Hiroshi Kadowaki¹, Wing Kam Liu²

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.3, pp. 269-282, 2005, DOI:10.3970/cmes.2005.007.269

Abstract A method to derive governing equations and elastic-plastic constitutive relations for the micropolar continuum model is proposed. Averaging procedures are operated over a surrounding sub-domain for each material point to bridge a discrete microstructure to a macro continuum model. Material parameters are determined by these procedures. The size of the sub-domain represents the material intrinsic length scale, and it is passed into the macroscopic governing equation so that the numerical solution can be regularized for analyses of failure phenomena. An application to a simple granular material model is presented. More >

Youping Chen¹, James D Lee², Azim Esk,arian¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.1, pp. 35-44, 2004, DOI:10.3970/cmes.2004.005.035

Abstract This paper addresses the need of theories and simulations for material body of mesoscopic and microscopic sizes. An overview of polar theories is presented. The micropolar theory proposed by Eringen is introduced and compared with other polar theories. Constitutive equations of micropolar thermo-visco-elastic solid are derived. Finite element analyses have been performed for a few sample problems with wide range of length scales. Based on the discussion, comparison and computer simulations, the unique feature and applicability of micropolar theory are demonstrated. More >

H. Imtiaz¹, F. M. Mahfouz²

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.3, pp. 171-192, 2015, DOI:10.3970/cmes.2015.108.171

Abstract This paper investigates numerically the conjugate heat transfer in a concentric enclosure that is formed between two concentric cylinders and filled with micropolar fluid. The wall of inner cylinder is considerably thick, while the wall of outer cylinder is very thin. The inner cylinder is heated from inner side through constant heat flux, whereas the outer cylinder is cooled and maintained at constant temperature. The induced buoyancy driven flow and associated conjugate heat transfer are predicted numerically by solving flow and energy governing equations considering a combination of finite difference and Fourier spectral methods. The study investigates the effect of… More >

M. D. Shamshuddin^{1, *}, P. V. Satya Narayana²

FDMP-Fluid Dynamics & Materials Processing, Vol.14, No.1, pp. 57-86, 2018, DOI:10.3970/fdmp.2018.014.057

Abstract In the present paper, a numerical analysis is performed to study the primary and secondary flows of a micropolar fluid flow past an inclined plate with viscous dissipation and thermal radiation in a rotating frame. A uniform magnetic field of strength Bo is applied normal to the plane of the plate. The whole system rotates with uniform angular velocity about an axis normal to the plate. The governing partial differential equations are transformed into coupled nonlinear partial differential equations by using the appropriate dimensionless quantities. The resulting equations are then solved by the Galerkin finite element method. The influencing pertinent… More >

J.R. Lin¹, T.L. Chou², L.J. Liang², M.C. Lin², P.H. Lee²

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 49-61, 2015, DOI:10.3970/fdmp.2015.011.049

Abstract The characteristics of a hydromagnetic non-Newtonian squeeze film formed between parallel rectangular plates under the application on an external magnetic field are investigated. A specific hydromagnetic non-Newtonian Reynolds equation is derived via pplication of the hydromagnetic flow theory together with the micro-continuum theory. It is found that the coupled effects of electrically conducting fluids and micropolar fluids result in a higher load capacity and a longer approaching time with respect to the non-conducting Newtonian case. These improved characteristics become more pronounced as the magnetic Hartmann parameter, the coupling parameter, and the fluid-gap parameter are increased. More >

J.R. Lin¹, L.M. Chu², T.L. Chou³, L.J. Liang³, P.Y. Wang³

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 163-177, 2014, DOI:10.3970/fdmp.2014.010.163

Abstract We investigate the influence of non-Newtonian micropolar fluids on the dynamic characteristics of wide tapered-land slider bearings. The study is carried out on the basis of the micro-continuum theory originally developed by Eringen (1966). Analytical expressions for the linear dynamic coefficients are provided and compared with earlier results in the literature. In particular, direct comparison with the Newtonian fluid-lubricated tapered-land bearings by Lin et al. (2006) indicates that the use of non-Newtonian micropolar fluids can lead to a significant increase in the values of stiffness and damping coefficients. Such improvements are found to be even more pronounced for larger values… More >

SamiaM.Said¹

CMC-Computers, Materials & Continua, Vol.52, No.1, pp. 1-24, 2016, DOI:10.3970/cmc.2016.052.001

Abstract The present paper is concerned with the wave propagation in a micropolar thermoelastic solid with distinct two temperatures under the effect of the magnetic field in the presence of the gravity field and an internal heat source. The formulation of the problem is applied in the context of the three-phase-lag model and Green-Naghdi theory without dissipation. The medium is a homogeneous isotropic thermoelastic in the half-space. The exact expressions of the considered variables are obtained by using normal mode analysis. Comparisons are made with the results in the two theories in the absence and presence of the magnetic field as… More >

G. Q. Xie^1,2, S. Y. Long^1,3

CMC-Computers, Materials & Continua, Vol.4, No.1, pp. 11-20, 2006, DOI:10.3970/cmc.2006.004.011

Abstract The concept of the micropolar theory is employed to investigate vibration behaviors of carbon nanotubes. The constitutive relation has been deduced from the two-dimensional analysis of the microstructure of the carbon nanotube. Van der Waals interactions are simulated by a weak spring model. Hamilton's principle is employed to obtain dynamics equations of the multi-walled carbon nanotube. Numerical examples for both single-walled and double-walled carbon nanotubes are presented and the significant difference in vibration behaviors between them has been distinguished. Numerical results show that fundamental frequencies for the cantilever single-walled carbon nanotube decreases with increase of the aspect ratio of them,… More >