Numerical Approach Determining the Optimal Distance Separating from Two Electric Cables

Abstract

In this work we present a two-dimensional numerical study of laminar natural convection in a square cavity, containing two circular-shaped heat sources that represent two electric cables in which an electric current produces a Joule effect heat release. These cables are at the edge of an AIRBUS aircraft and their excessive heating can cause material and human damage. The objective of the study, is to determine the optimal distance between these two sources to avoid excessive heating of the installation. Different cases have been examined by varying the distance between the two heat sources and their angle of inclination and this for different values of the Rayleigh number. The governing equations were numerically solved by a FORTRAN calculation code based on the finite volume method. The results obtained show that the heat transfer in the cavity is affected mainly by the spacing between the two heat sources and the variation of the Rayleigh number. Indeed, for the horizontal position (α = 0°), heat sources we note the heat transfer in the cavity is maximum (Nua = 14.69), for a distance between the heat sources equal to 0.7 and a value of Rayleigh 106. In the case where the heat sources are inclined (α = 45°), the heat transfer is better (Numoy = 20.91) for a distance between the two sources equal to 0.4 and a value of Rayleigh 105. In the vertical position of heat sources (α = 90°), there is a maximum heat transfer (Numoy = 47.64) for a distance between the heat sources equal to 0.7 and a Rayleigh value equal to 106. In conclusion we can say that the optimal distance between the two heat sources and which was the object of this study is reached in the case where the sources are in vertical position (α = 90°), and spaced from a distance (d) equal to 0.7. (a) α = 0°, d = 0.7 (b) α = 45°, d = 0.4 (c) α = 90°, d = 0.7.

Keywords: natural convection, heat source, optimal distance, finite volume