Discharge Coefficient of Pressure-Swirl Atomizers with Low Nozzle Opening Coefficients

摘要

An experimental study on the discharge coefficients of 44 different pressure-swirl atomizer configurations with a wide range of nozzle opening coefficients was conducted. The experimental results show that the discharge coefficients of specific injector geometries, especially those with low nozzle opening coefficients, are not in accord with the other existing models. For the design of injectors that are used in rocket engines, ascertaining an appropriate discharge coefficient that is closely related to the spray angle and liquid film thickness is significant. Moreover, the injector pressure drop affects the pressure budget that is allocated for the other subsystems of liquid rocket engines. Actually, pressure-swirl atomizers with low nozzle opening coefficients are preferred considering the available installation space in the combustion chamber manifold. Therefore, a novel empirical equation was proposed to accurately predict the discharge coefficient of pressure-swirl atomizers with low nozzle opening coefficients. The discharge coefficients predicted by the proposed empirical equation are in good accord with the measured values when compared with the other existing models.