Computational Study of a Four-Funnel Converging–Diverging Infrared Suppression Device

Abstract

This research presents a computational exploration of an infrared suppression (IRS) configuration featuring four tapering flues in a converging–diverging sequence. Intended for aerospace propulsion systems, the design functions by mixing exhaust gases with entrained ambient air, lowering plume temperature and infrared emission levels. The study evaluates entrainment characteristics and outlet gas temperatures under varying Reynolds numbers, inlet temperatures, and funnel overlaps. The analysis employs conservation principles of mass, momentum, and energy, solved numerically to capture both flow dynamics and heat transfer. The findings highlight how operating and geometric parameters affect non- dimensional entrainment ratios and temperature profiles. Special emphasis is placed on the effect of inlet air temperature across flow regimes. Results demonstrate the potential of conical funnel IRS units as passive cooling solutions, providing insights into thermal signature control strategies.