This study addresses the complex thermo-physical properties of an Infrared Suppression System (IRS). A two-dimensional axisymmetric setup consists of stacked conical funnels, one converging and the other diverging, creating a challenging flow environment due to the interplay of hot turbine exhaust, ambient air intake, and hot-cold air mixing. A critical focus is placed on the radial gap between these funnels, significantly impacting mass entrainment into the IRS. Altering this gap changes the second funnel's diameter, potentially affecting radar detectability. The study's objectives involve investigating how the radial gap (ROL) influences mass entrainment and the outlet air temperature ratio to the surrounding air. Numerical simulations provide insights, employing mass, momentum, and energy conservation equations within a cylindrical computational domain around the IRS device. Various initial conditions are explored. This research advances our understanding of IRS system dynamics and offers practical implications for optimizing similar systems, particularly in scenarios where radar detection remains a concern. The current numerical computation shows that the mass entrainment ratio increases with the ROL but decreases significantly afterward.