Flow and conjugate heat transfer with surface radiation characteristics of a real-scale infrared suppression device with conical funnels

Abstract The precise flow and heat transfer aspects in an infrared suppression (IRS) device are challenging because of the complicated flow features. The suction of cold ambient air and subsequent mixing with the hot exhaust gas from the turbine in cargo/naval ships happens in the IRS device. In the present research, the thermo-fluid characteristics of a two-dimensional axisymmetric IRS system consisting of conical funnels stacked one above the other are meant to study. Numerical simulations are performed for the real-scale IRS unit by solving the equations of mass, momentum, energy, and radiation in the computational domain surrounding the IRS device. In this study, the effect of conducting funnel walls with surface radiation is considered. The impact of the number of funnels on mass intake and the device outlet temperature is analyzed. The results show that the maximum air intake and minimum outlet temperature can be achieved using five funnels. The mass intake and device outlet temperature are also affected by funnel-overlapping and nozzle-overlapping. The maximum air intake and minimum outlet temperature are obtained by zero funnel-overlapping and zero nozzle-overlapping conditions. When the adiabatic funnel is replaced by conducting funnels with surface radiation, the increment in the mass intake and decrement in outlet temperature is observed. The impact of funnel wall inclination and the type of guide vanes are also discussed.