Air entrainment study of a converging-diverging type IRS device: A numerical exercise

Abstract

The present numerical calculation considers a converging-diverging funnel-type real-scale IRS (infrared suppression) device made up of two conical funnels, one above the other. The device's mass suction and outlet temperature are calculated by changing geometrical and operational parameters, such as the Reynolds number, inlet temperature, funnel, and exhaust pipe overlapping. For the current computation, the effect of the above parameter on the non-dimensional mass entrained and the outlet temperature was studied. Various governing equations like mass, momentum, and energy conservation are applied to the computational domain for a real-scale IRS device. The numerical computation results indicate that the inlet temperature significantly impacts the mass entrainment ratio more than the Reynolds number. This impact is quite visible for the Reynolds number at higher inlet temperatures. A better mass entrainment ratio is achieved at a negative overlap, but the changes are negligible after a negative funnel overlap of 0.4 m. Similarly, mass entrainment improves when the exhaust pipe is kept far from the bottom funnel. This study proposes new correlations for mass entrainment and outlet temperature ratios.