Study of Wall Jets in Duct Diffuser Systems.
Final technical rept. Apr-Sep 74,
MARTIN MARIETTA AEROSPACE DENVER COLO DENVER DIV
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The effectiveness of wall jets in preventing diffuser stall in a simulated two-dimensional thrust augmenter was experimentally investigated. The tests were conducted in the static mode that is, the flow through the inlet of the model was free from ram-air effects. The velocity of the airflow through the model ranged from 90 to 260 fts while the area ratio of the diffuser was systematically varied from 1.73 to 2.72. The wall-jet slot height was varied from 0.05 to 0.196 in. Nitrogen wall jets were found to be an effective means of suppressing stall. For a given diffuser area ratio and wall-jet slot height, the minimum wall-jet mass flow was an almost constant fraction of the primary air mass flow. From the standpoint of power required to suppress stall, larger jets were more efficient.
- Fluid Mechanics