Optimum spacing of vertical parallel plates for combined natural convection and radiation

The reliability of electronic products depends on their ability to dissipate the heat generated by various components. Application of an array of parallel plates such as a heat sink is a common example of using parallel plates in electronics cooling. The most common practice in dissipation of the heat generated by electronics is by means of natural convection. Others have investigated the optimum spacing of vertical parallel plates for the maximum natural convection heat transfer. The goal of this study is to determine the optimum spacing for the maximum combined natural convection and radiation heat transfer from an array of isothermal parallel plates. An exact correlation was obtained to determine the optimum spacing for the maximum radiation heat transfer alone. It is concluded that the optimum spacing for the combined natural convection and radiation heat transfer is similar to that of the optimum spacing of the natural convection alone. An exact correlation was also obtained to determine the optimum spacing for combined heat transfer.