Diffusion Foundations Vol. 26

Abstract: In this paper, a fractional relaxation model is studied to determine the effect of heat transfer and magnetic field on the blood flow. The flow is due to an oscillating periodic pressure gradient and body acceleration. We apply Laplace transform as well as finite Hankel transform to obtain the closed form solutions of the velocity and temperature distributions of the fractional time partial differential equations. Effect of the fluid flow parameters are shown graphically with changes in the ordinary model as well as the fractional parameters. The analysis shows that the fractional derivative is an excellent tool which gives remarkable change in controlling temperature and blood flow. The analysis depicts graphically, that in the presences of strong applied (exterior) magnetic field, reduces the temperature and blood flow velocities, which is appropriate to avoid tissues damage during treatment. In addition, it is seen that some of the aforementioned parameters influenced the fluid flow profiles in increasing and decreasing fashion which is interpreted as useful to the study.

Abstract: We extend previous studies of channel flows to porous media flows with combined effects ofboth heat and mass transfer. We consider a temperaturedependent viscosity fluid and a concentrationdependent diffusivity in an unsteady and pressuredriven nonisothermal Brinkman flow. This leads to the governing equations for velocity, concentration and temperature. By lagging nonlinear coefficients, in time, a convergent finite difference scheme is formulated. We adopt the method of manufactured solutions to verify the convergence and second order spatial accuracy of the scheme. The impact of the flow parameters on the flow fields are numerically investigated. The results show that increase in the Darcy number and temperature parameter both increase the velocity while the increase in the pollutant diffusion parameter decreases the pollutant concentration.

Abstract: In order to reduce the operating costs of the engine, turbine designers must also increase the life of their components. However, high gas temperatures throughout the engine require more cooling air or better cooling efficiency to protect the parts from thermal damage. This study presents numerical research on cooling holes. Research focused on aerodynamics and thermal aspects of shallow whole angle. The numerical simulation is performed based on Reynolds Averaged Navier-Stokes (RANS) equations with SST turbulence model by using CFX. A modification has been done in the normal injection hole of 35°, by injecting the cold fluid at different blowing ratio, providing a significant change in the shape of holes which later we found in our numerical investigation giving good quality of film cooling effectiveness.