Effect of Location of Rectangular Orifice on the Momentum flow of Power-law Fluids

Abstract

The present work numerically investigates the flow of power-law fluids through a square-edged rectangular orifice. This study has been carried out for a wide range of power-law index (0.3 - 1.0) and three lateral positions of the orifice (0.5 - 0.75) at a fixed Reynolds number (i.e., 20) and aspect ratio (i.e., 0.5). This work aims to understand the influence of the shift of the location of the orifice in the lateral direction on the flow characteristics. The new results have been presented in this work in the form of flow patterns, central and lateral velocity profiles, and the discharge coefficient. Notably, the flow pattern demonstrates the formation of symmetric and antisymmetric flow separation zones in the vicinity of the orifice, depending upon the orifice location, regardless of the power-law index. In this work, an effort has been made to analytically derive the equation for the discharge coefficient of non-Newtonian fluids through the rectangular channel and presented the same for a wide range of conditions. Results demonstrate that the flow velocities, i.e., centreline and lateral velocity profiles are a strong function of the governing parameters and orifice location. The discharge coefficient is seen as an increasing function of the orifice location as it shifts in the lateral direction, towards the upper wall of the computational domain. Also, a dramatic effect of the power-law index on the discharge coefficient has been observed herein for a particular orifice location.