Natural convection cooling of an infrared suppression device (IRS) with conical funnels- a computational approach

摘要

The present study involves the numerical computations of the free convection heat transfer from an Infrared suppression device with the conical funnels, which is used in the exhaust of the marine gas turbines and helicopters. The computations have been performed in the range of 10~(10) ≤ Ra ≤10~(12). The study also involves predicting the effect of the diameter ratio and the percentage overlap. Besides, our study proposes a correlation for the Nusselt number and the induced mass flow rate in terms of Rayleigh number, diameter ratio, and percentage overlap. The study also computes the cooling time of the IRS device. The Nusselt number initially increases with the diameter ratio, attains a maximum, and finally reduces to a constant value. Highest values of Nu are observed with the positive overlap of the funnels, whereas the lowest values are obtained for the negative overlap. Moreover, the present study also compares the cooling characteristics of the IRS having cylindrical and the conical funnels. The comparisons show that higher values of the Nu are obtained for the cylindrical funnels compared to the conical ones. The findings of the present study can be significant to both the engineers of the ship industries and the academicians.