An analytical investigation of the effectiveness of water injection for engine-inlet matching and thrust augmentation was made at Mach num¬bers from 1.5 to 2.0. One-dimensional equations for complete evaporation in a constant-area channel were applied to a fixed-geometry inlet, and its flight performance was compared with bypass and translating-spike inlets.nNo-spillage engine-inlet matching was achieved over the Mach number range studied with maximum liquid-air ratios of about 0.03. Augmented thrust due to injection ranged from 17 to 56 percent higher than that of the best performing variable-geometry inlet. However, the specific im¬pulse (thrust/(lb)(sec of liquid consumption)) of the water-injection in¬let configuration was considerably lower than that of the bypass inlet and about equal to that of a fixed-geometry configuration without water injection. The total liquid consumed by the water-injection system, at matching, was one-half to two and one-half times greater than the bypass inlet configuration.
展开▼
