Abstract: A computational method for determining the size of orifices used for distributing and limiting the cooling system air flow for the electronic devices in equipment cabin" of airplane is presented. A functional relation of an experimental curve quoted in this paper was founded. The diameter "of the. orifice is calculated by using the relation curve above motioned and the law of fluid dynamics. The Comparison between the Calculated results and test results shows that the proposed method is satisfactory to engineering application.

Key words: electronic equipment cabin, resEricted orifice, pressure-loss, air conditioning flow