Numerical Characterization of Lip Thickness on Subsonic and Correctly Expanded Sonic Co-flowing Jets

Abstract

Characteristics of co-flowing jets at subsonic and correctly expanded sonic Mach numbers were investigated numerically for three different lip thicknesses namely, 0.2D p , 1.0D p and 1.5D p (where D p is the exit diameter of the primary nozzle which is 10 mm). Comparisons of numerical flow-field characteristics were made with experimental data. Lip thickness is defined as the thickness of the wall separating primary jet and the secondary jet. It has been found that co-flow with 0.2D p lip thickness retards the mixing of the primary jet, leading to potential core elongation. For 1.0D p and 1.5D p lip thickness, the presence of lip thickness creates a recirculation zone between the primary jet and the secondary jet, which increases turbulence intensity in the near-field region of the co-flowing jet thereby influencing the properties in the nearfield, such as potential core length reduction, static pressure rise, etc. Variation in Mach number has less significance in the flow-field characteristics of co-flowing jet.

Investigation of Jet Mixing Characteristics Using Slotted Rectangular Tabs

“…Grooved and chevron nozzles are used as certain techniques in jet flow control (Elangovan and Rathakrishnan 2004;Tide and Srinivasan 2010;Kumar et al 2011). Nozzles are also modified to issue co-flowing jets to control the flow in the subsonic regime (Lovaraju and Rathakrishnan 2011;Shankar et al 2016;Shankar et al 2018;Shankar and Bennett 2019;Thanigaiarasu et al 2019;Shankar and Raja 2020).…”