AN EXPERIMENTAL INVESTIGATION INTO THE SHAPE OF THRUST-AUGMENTING SURFACES IN CONJUNCTION WITH COANDA-DEFLECTED JET SHEETS (PART 1)
TORONTO UNIV DOWNSVIEW (ONTARIO) INST FOR AEROSPACE STUDIES
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It is known that by means of additional surfaces, the thrust of a jet or jet sheet can be enhanced thrust augmentation. This especially applies to Coandadeflected jet sheets because of the inherent stronger entrainment into curved flow surfaces. The flow from a two-dimensional subsonic nozzle was deflected by quadrants. A composite thrust-augmenting surface was added, and the effect of its shape on thrust augmentation was studied at various nozzle pressure ratios and radii of the quadrants. This investigation yielded a maximum thrust augmentation of 1.21 for several optimum configurations, which was governed primarily by the relative magnitude and direction of the momentum of the secondary entrained flow in relation to the primary nozzle flow momentum. Thrust augmentation decreased with increasing nozzle pressure ratio but was independent of the quadrant radius. Some of the observed results were predicted theoretically. Suggestions for possibly introducing higher thrust augmentation are offered.
- Fluid Mechanics
- Jet and Gas Turbine Engines