Computer Optimization of Water-Augmented Turbofan Concept and Development of a Test Facility for Two-Phase Flow

摘要

A turbofan engine propulsion system in which large amounts of water are injected into the fan discharge duct is investigated with the goal of increasing both the thrust and propulsive efficiency while retaining the light-weight qualities of a standard turbofan engine. A parametric computer analysis is used to examine the effect of several variables, including water-to-gas generator air ratio, water injection velocity, fan duct pressure loss, and fan duct thermal and dynamic nonequilibrium, upon thrust and propulsive efficiency. In addition, the design parameters of fan pressure ratio and fan bypass ratio are examined for their optimum values, and optimum operating combinations of water-to-gas ratio and water injection velocity are determined. A test apparatus is developed for the direct measurement of wall friction force in two-phase flows. A computer program is presented to reduce experimental data and compare with pressure drop predicted by two empirical correlations. (Author)