Narrow Results

The study of the blood flow through arterial walls is an important subject due to different chemical reactions and magnetohydrodynamic having an impact on the arterial walls during the treatment of cancer, malignant tumors, drug targeting and endoscopy. So, this paper aims to present a comprehensive investigation of the blood bioconvective flow of Carreau–Yasuda (C–Y) nanofluids in an arterial. Variable velocity conditions near the walls are considered. The flow domain is filled by a porous medium and a time-dependent magnetic field is assumed. The impacts of an exponential chemical reaction are considered and the viscous dissipation in the case of the C–Y model is formulated and examined. The fully implicit finite difference method is applied to solve the dimensionless governing system. The case of the shear thinning $(n=0.5)$ and shear thickening $(n=1.5)$ are analyzed for the variations of the governing parameters such as Weissenberg $(0.001\le \mathrm{\text{We}}\le 0.1)$ and parameter of the porous medium $(0\le \beta \le 2)$. The major outcomes revealed that the friction coefficient is improved as the C–Y parameter is raised. Also, values of heat and mass transfer are higher in the case of the shear thinning compared to the shear thickening.

Numerical simulation of thermal stress during casting solidification process can predict crack, residual stress concentration, deformation. Though stress simulation involves too many complex problems such as numerical model, mechanical boundary condition and high thermo-mechanical parameters, it still retains as a difficult hotspot of macro-simulation of casting nowadays. Based on finite difference method (FDM), a 3D FDM/FDM numerical simulation system for temperature and stress analysis during casting solidification process was developed. To verify the system, a standard stress frame model and a practical casting were simulated. Pouring experiments have been carried out in the laboratory. The results of simulation coincided with those obtained from experiment and practical results. When adopting FDM to calculate casting thermal stress, thermal analysis and stress analysis can use the same FD model, which can avoid matching between different models and reduce the errors of temperature load transferring. It makes the simulation of fluid-flow, temperature and stress unify into one model.