The theoretical amount of discharge of steam through orifices can be found by so called Saint Venant and Wantzel's equation, but owing to the various disturbances occuring in the orifices, the actual amount is not equal to the theoretical one. Bendemann found a very convenient empirical formula expressing the amount of discharge of steam through circular orifices with well rounded entrance, but for the orifices of other forms, it is unknown whether his equation can be applied or not. To confirm this point, the experiments were performed with eight orifices of different forms and dimensions as given in Fig. 2 and Table I, and the results may be summerized as follows : Under the same condition of steam, the same values of rate of discharge per unit area can be given for orifices A and B, for orifices C, D, E and F, and for orifices E′ and F′, the amount of discharge can be represented either by Bendemann's equation or by an equation introducting a coefficient of discharge expressed as a linear function of pressure ratio to the theoretical equation, the latter equation being accurately applied for orifices with sharp entrance than the former one.
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