Muhammad Sami Rashad¹, Haihu Liu^1,*, Shan Ali Khan²

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.1, pp. 233-254, 2022, DOI:10.32604/cmes.2022.017277

Abstract A mathematical modeling is explored to scrutinize the unsteady stagnation point flow of Oldroyd-B nanofluid under the thermal conductivity and solutal diffusivity with bioconvection mechanism. Impacts of Joule heating and Arrhenius activation energy including convective boundary conditions are studied, and the specified surface temperature and constant temperature of wall (CTW) are discussed. The consequences of thermal conductivity and diffusivity are also taken into account. The flow is generated through stretchable disk geometry, and the behavior of non-linear thermal radiation is incorporated in energy equation. The partial differential equations governing the fluid flow in the structure is reduced into dimensionless nonlinear… More >

Safia Akram^*, Alia Razia

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 901-922, 2021, DOI:10.32604/cmes.2021.014469

Abstract This article brings into focus the hybrid effects of thermal and concentration convection on peristaltic pumping of fourth grade nanofluids in an inclined tapered channel. First, the brief mathematical modelling of the fourth grade nanofluids is provided along with thermal and concentration convection. The Lubrication method is used to simplify the partial differential equations which are tremendously nonlinear. Further, analytical technique is applied to solve the differential equations that are strongly nonlinear in nature, and exact solutions of temperature, volume fraction of nanoparticles, and concentration are studied. Numerical and graphical findings manifest the influence of various physical flow-quantity parameters. It… More >

G. Kanevce¹, L. Kanevce², V. Mitrevski³, G. Dulikravich⁴

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.1, pp. 1-6, 2008, DOI:10.3970/icces.2008.008.001

Abstract This paper deals with the application of inverse concepts in drying. The objective of the paper is estimation of the moisture diffusivity of a drying body by using only temperature measurements. Potato and apple slices have been chosen as representative drying bodies with significant shrinkage effects. A mathematical model of the drying process of shrinking bodies has been applied. The Levenberg-Marquardt method and a hybrid optimization method of minimization of the least-squares norm were used to solve the present parameter estimation problem. More >

N. Ohba^1,2, S. Ogata², T. Tamura², S. Yamakawa¹, R. Asahi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.75, No.3&4, pp. 247-266, 2011, DOI:10.3970/cmes.2011.075.247

Abstract Understanding the stress dependence of Li diffusivity in the Li-graphite intercalation compound (Li-GIC) that has been used in the Li-ion rechargeable battery as a negative electrode, is important to search for better conditions to improve the power performance of the battery. In the Li-GIC, the Li ion creates a long-ranged stress field around itself by expanding the inter-layer distance of the graphite. To take into account such a long-ranged stress field in the first-principles simulation of the Li diffusion, we develop the hybrid quantum (QM)-classical (CL) simulation code. In the hybrid code, the QM region selected adaptively around the Li… More >

V.C. Mariani¹, V. J. Neckel², L. S. Coelho³

CMES-Computer Modeling in Engineering & Sciences, Vol.68, No.2, pp. 167-184, 2010, DOI:10.3970/cmes.2010.068.167

Abstract In this study an inverse heat conduction problem using two optimization methods to estimate apparent thermal diffusivity at different drying temperatures is solved. Temperature and moisture versus time were obtained numerically using heat and mass transfer equations with drying temperatures in the range between 20°C to 70°C. The solution of the partial differential equation is made with a finite difference method coupled to optimization techniques of Differential Evolution (DE) and Particle Swarm Optimization (PSO) used in inverse problem. Statistical analysis shows no significant differences between reported and estimated curves, and no remarkable differences between results obtained using DE and PSO… More >

Antoine Fabre¹, Jordan Hristov^2*, Rachid Bennacer¹

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.2, pp. 69-85, 2016, DOI:10.3970/fdmp.2016.012.069

Abstract Closed form approximate solutions to nonlinear transient heat conduction with linear power-law k = k₀(1±βT^m) temperature-dependent thermal diffusivity have been developed by the integral-balance integral method under transient conditions. The solutions use improved direct approaches of the integral method and avoid the commonly used linearization by the Kirchhoff transformation. The main steps in the new solutions are improvements in the integration technique of the double-integration technique and the optimization of the exponent of the approximate parabolic profile with unspecified exponent. Solutions to Dirichlet boundary condition problem have been developed as examples by the classical Heat-balance Integral method (HBIM) and the… More >