Natural Convection of Non-Newtonian Dilatant Fluid in the Gap Between an Outer Cylinder and Inner Cylinder With Grooves

Abstract

This paper reports a numerical study of the laminar free convection of dilatant fluid between two concentric cylinders. The simulations have been performed for the two-dimensional steady state and the ANSYS CFX 16.2 was used as theoretical-computational approach to achieve detailed and realistic results. The finite volume method was used for that objective. The governing problem parameters are taken as 1 ≤ <i>n</i> ≤ 1.6,10 ≤ Pr ≤ 10<sup>3</sup>, 10<sup>3</sup>≤ Ra ≤ 10<sup>5</sup> and a different number of grooves was added to the inner cylinder (4, 8, 12, and 16). We give detailed explanations on the effects of the precedent coefficients on the streamlines, isotherms, velocity, and dimensionless temperature. It is found that dilatant fluids display the behavior like a solid more than a solution. The Rayleigh number strengthens the convective flow which refers by increasing in the Nusselt number at the same set of the other parameters. Also, the important phenomenon here (effects of the grooves) will take a large part from the discussion section. When the grooves accomplished a given number and <i>n</i> is high, the fluid is stiff and the heat transfer mode is purely by conduction.