LAUSR

Abstract A numerical simulation has been performed to study the natural convection cooling of an IRS device by varying Rayleigh number in the range of 1010 to 1012. Computations are carried out by varying the diameter ratio (DR) in the range of 1.02–1.3. Navier-Stokes equations and energy equation have been numerically simulated for a full-scale IRS device using the algebraic multi-grid solver of FLUENT 16 with a two-equation eddy viscosity based turbulence model. It was found that with the increase in diameter ratio the heat transfer rate increases but the average Nusselt number initially increases and then decreases following a peak value. The effect of diameter ratio, funnel overlap and Ra on Nusselt number, induced mass flow rate and cooling time has been discussed along with the correlations for average Nusselt number and induced mass flow rate which can be very beneficial to the shipping industry.