Ahlam Aljabali¹, Abdul Rahman Mohd Kasim^1,*, Nur Syamilah Arifin², Sharena Mohamad Isa³, Noor Amalina Nisa Ariffin¹

CMC-Computers, Materials & Continua, Vol.66, No.1, pp. 675-689, 2021, DOI:10.32604/cmc.2020.012334

Abstract Non-Newtonian is a type of fluid that does not comply with the viscosity under the Law of Newton and is being widely used in industrial applications. These include those related to chemical industries, cosmetics manufacturing, pharmaceutical field, food processing, as well as oil and gas activities. The inability of the conventional equations of Navier–Stokes to accurately depict rheological behavior for certain fluids led to an emergence study for non-Newtonian fluids’ models. In line with this, a mathematical model of forced convective flow on non-Newtonian Eyring Powell fluid under temperature-dependent viscosity (TDV) circumstance is formulated. The fluid model is embedded with… More >

Mohamed Abd El-Aziz^{1, 2}, A. M. Aly^{1, 3, *}

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 525-549, 2020, DOI:10.32604/cmc.2020.08576

Abstract This study focusses on the numerical investigations of boundary layer flow for magnetohydrodynamic (MHD) and a power-law nanofluid containing gyrotactic microorganisms on an exponentially stretching surface with zero nanoparticle mass flux and convective heating. The nonlinear system of the governing equations is transformed and solved by Runge-Kutta-Fehlberg method. The impacts of the transverse magnetic field, bioconvection parameters, Lewis number, nanofluid parameters, Prandtl number and power-law index on the velocity, temperature, nanoparticle volume fraction, density of motile microorganism profiles is explored. In addition, the impacts of these parameters on local skin-friction coefficient, local Nusselt, local Sherwood numbers and local density number… More >

Mohamed Abd El-Aziz^{1, 2}, A. M. Aly^{1, 3, *}

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 37-59, 2020, DOI:10.32604/cmc.2020.08488

Abstract In the present study, the effects of the magnetic field on the entropy generation during fluid flow and heat transfer of a Sisko-fluid over an exponentially stretching surface are considered. The similarity transformations are used to transfer the governing partial differential equations into a set of nonlinear-coupled ordinary differential equations. Runge-Kutta-Fehlberg method is used to solve the governing problem. The effects of magnetic field parameter M, local slip parameter λ, generalized Biot number γ, Sisko fluid material parameter A, Eckert number Ec, Prandtl number Pr and Brinkman number Br at two values of power law index on the velocity, temperature,… More >

H.B. Chen

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.4, pp. 105-106, 2011, DOI:10.3970/icces.2011.020.105

Abstract The calculation of field values and their derivatives near the domain boundary through the boundary element method (BEM) will meet the nearly singularity problem, i.e. the boundary layer effect problem. The tangential derivatives of field values on the boundary often meet an obvious deduction of calculation accuracy. An effective algorithm was proposed by Chen et al. [1,2] to treat these two problems in the same time in elastic BEM and it was recently extended to calculate the second derivative values in potential problem [3]. This algorithm is based on the regularized formulations and is now called the regularized indirect algorithm.… More >

S. R. Atashipour¹, A. R. Saidi²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.14, No.3, pp. 91-96, 2010, DOI:10.3970/icces.2010.014.091

Abstract In this article, the bending equations of thick annular sector plates are derived based on the third-order shear deformation theory (TSDT). Using a function, called boundary layer function, the coupled system of equations is converted into two decoupled equations and solved analytically. It is shown that the value of the boundary layer function for TSDT is higher than that of the Mindlin theory. Thus, variations of stress components in the edge zone of the plate are more significant. It is seen that there exist no boundary layer, a weak boundary layer, and a strong boundary layer effect for simply supported,… More >

Witold Elsner^1,*, Artur Dróżdż¹, Paweł Niegodajew¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 41-41, 2019, DOI:10.32604/icces.2019.05114

Abstract Estimation of the wall skin friction in a turbulent boundary layer (TBL) is always challenging due to the large gradient of mean velocity in the near-wall region and requires precise measurements of mean velocity in viscous sublayer. This problem becomes even more serious for a flow with a strong positive pressure gradient where the low velocity closes the wall occurs. Hence, choosing an appropriate measuring technique for the wall skin friction measurement is an important issue. Most commonly used for this purpose is hot-wire technique, where determination of mean velocity gradient is strongly dependent on resolution and quality of measurements… More >

Wen-Hwa Chen¹, Cheng-Hung Chen²

CMES-Computer Modeling in Engineering & Sciences, Vol.8, No.3, pp. 177-190, 2005, DOI:10.3970/cmes.2005.008.177

Abstract An enriched meshless method, using meshless interpolations and a global Galerkin approach, is developed for the analysis of three-dimensional fracture problems. The displacement field which accounts for the stress singularity nearby the crack front and the boundary layer effect at the intersection between the crack front and the free surface of the structure is adopted to enrich the trial functions. The three-dimensional stress intensity factors can thus be treated as independent unknown parameters and calculated with the nodal displacements directly. To estimate the accuracy of the method developed, several representative three-dimensional cracks are analyzed. These include single-edge crack, embedded elliptical… More >

J. Qiu¹, T. Hayase¹, T. Okutani¹

CMC-Computers, Materials & Continua, Vol.1, No.4, pp. 301-308, 2004, DOI:10.3970/cmc.2004.001.301

Abstract In this study, three types of surface motion of wall motion actuators were proposed and used to control the Tollmien-Schlichting (T-S) wave in the laminar boundary layer of a plate. These three types of motion are standing transverse wave (with out-of-plane displacement), traveling transverse wave (with out-of-plane displacement) and standing longitudinal wave (with in-plane displacement). The length of a wall motion actuator was set to 1, 2 or 3 cycles of waveform. Numerical simulation was performed on the generation of T-S wave and its suppression with the three types of surface motion of the wall motion actuator and the dependence… More >

Sun-Chien Ko^1,2, Chen-Ti Hu¹, Sanboh Lee¹, Y.T. Chou³

CMC-Computers, Materials & Continua, Vol.28, No.2, pp. 165-180, 2012, DOI:10.3970/cmc.2012.028.165

Abstract The chemical stresses developed in a cylindrical sandwich composite during radial boundary layer diffusion have been investigated. The system consists of a thin layer A of circular cross section sandwiched between two semi-infinite outer layers B, with the diffusivity of diffusant in A (D_A) being much greater than that in B (D_B). Two boundary conditions, the constant surface concentration and the instantaneous surface concentration, were considered. The concentration distributions were obtained by the Bessel-Laplace transform method. The stress functions were solved analytically based on the linear elasticity. Numerical computations were performed to illustrate the effects of the diffusivity ratio (D_A/D_B)… More >

Weiwei Li¹, Wen Chen^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.5, pp. 347-362, 2014, DOI:10.3970/cmes.2014.100.347

Abstract This paper presents an efficient strategy for the accurate evaluation of near-boundary solutions in the regularized meshless method (RMM), also known as the boundary layer effect associated with the boundary element method. The RMM uses the double layer potentials as its interpolation basis function. When the field point is close to the boundary, the basis function will present nearly strongand hyper-singularities, respectively, for potentials and its derivative. This paper represents the first attempt to apply a nonlinear transformation, based on sinh function, to the accurate evaluation of nearly singular kernels associated with the RMM. The accuracy and efficiency of the… More >