NUMERICAL STUDY OF HEAT AND FLUID FLOW PAST A CUBICAL PARTICLE AT SUBCRITICAL REYNOLDS NUMBERS

Abstract

This work is devoted to a numerical investigation into heat and fluid flow past a particle of a cubical shape. Additionally, it is a continuation of the recent publication by Richter and Nikrityuk (Int. J. Heat Mass Transfer, vol. 55, no. 4, pp. 1343−1354, 2012a), where the authors performed numerical calculations of drag forces and heat transfer coefficients for nonspherical particles in laminar flows with an angle of attack of zero. In this work we focus on the influence of the angle of attack on flow past a cubical particle. Due to the asymmetric flow, three-dimensional calculations were carried out based on the immersed boundary (IB) method in continuous forcing mode; see the review by Mittal and Iaccarino (Ann. Rev. Fluid Mech., vol. 37, pp. 239−261, 2005). In order to substantiate the results, additional calculations were made based on a so-called conventional computational fluid dynamics (CFD) solver using body-fitted meshes. Based on the present analysis of numerical results obtained for a cubical particle, new correlations for both the drag coefficient (cD) and the Nusselt number (Nu) were developed. In addition to the Prandtl and Reynolds numbers, both correlations incorporate the angle of attack. A significant influence of the particle orientation on the characteristics cD and Nu was observed. The accuracy of the closures developed for cD and Nu is discussed, comparing the relations developed with published models.