Evaluating the Impact of Free-Stream Turbulence on Convective Cooling of Overhead Conductors Using Large Eddy Simulations (LES)

Abstract

This study uses Large Eddy Simulation in the ANSYS Fluent software to assess the accuracy of the forced cooling term for the overhead conductor codes, IEEE 738 [1] and CIGRÉ 207 [2], for Real Time Thermal Rating of a wind farm power line. The analysis is done for low wind speed, corresponding to Reynolds Number of 3,000. The primary goal is to calculate Nusselt Number for cylindrical conductors with free-stream turbulence. Calculations showed an increase in convective heat transfer from the low turbulence value by ∼ 30 % at turbulence intensity of 21% and length scale to diameter ratio of 0.4; and an increase of ∼ 19 % at turbulence intensity of 8% and length scale to diameter ratio of 0.4.