複合エンジンの静止大気中における吸い込み性能

第2報：エジェクタ二層流解析と吸い込み性能改善

抄録

Two-stream flow model of ejector including heat and mass transfer was constructed by the comparison of the numerical simulations in the rocket-ramjet combined-cycle engine driven three different rocket gas; cold N₂ gas, hot combustion gas and it within excess H₂. The analysis of the ejector revealed that the heat and mass transfer from hot rocket plume with supersonic speed to cold airflow induced area change (expansion) of the airflow stream tube and the pressure rise in the constant-area section at the downstream of the rocket base. This pressure rise reduced the pumping performance of the ejector. To absorb the expansion of the airflow, the flowpath was changed from the constant area to the diverging area at the downstream of the rocket base. The numerical simulation in the modified engine demonstrated that the diverging-area section at the downstream of the rocket base improved the pumping performance.