Cooling Characteristic of an Infrared Suppression Device with Single Perforated Funnel: A Computational Fluid Dynamics Approach

An infrared suppression (IRS) device is integral to any gas turbine used in naval and cargo ships. Estimating an IRS device's cooling characteristics is essential to start the maintenance operation. Thus, this article presents a computational investigation of the cooling characteristics of an infrared suppression device with a single cylindrical funnel with or without circular perforations. All simulations have been carried out in a steady and laminar environment. The numerical procedure adopted in this work has been validated with the existing correlations and achieved satisfactory agreement. The effect of the Rayleigh number and the length-To-diameter ratio of the funnel have been varied within the practical range to observe their effects on the averaged Nusselt number, heat transfer rate, mass suction rate, velocity fields, and thermal plumes. Moreover, the cooling performance has been compared for funnels without and with circular perforations. It is observed that the average Nu and the heat transfer rate increase with an increase in the Ra. Conversely, the average Nu first increases and then reduces with an increase in L/D. On the contrary, the heat transfer rate decreases monotonically with an increase in the L/D. The suction of fresh air into the funnel increases with Ra, whereas it reduces with an increase in L/D. The perforated funnels have better heat dissipation capacity than the unperforated ones.