PERFORMANCE OF FLARED EXHAUST DUCTS SUITABLE FOR JET FLAP APPLICATIONS

摘要

The thrust loss and flow characteristics of flared ducts suitable for application in a jet flap or jet wing system were obtained experimentally. Three flared duct models were tested and results compared with the performance of a cylindrical duct configuration at given values of weight flow and pressure ratio.nThe results are presented in the form of velocity coefficient and flow coefficient versus pressure ratio for the various configurations. Also presented is the percent thrust loss relative to the cylindrical duct. Thrust losses as low as two percent were obtained for the best configuration tested and less than ten percent for the worst, a simple tinsmith's transition duct.nFlow distribution at the exit of the flared ducts was measured. This showed that maintaining uniform flow at the blowing slot for the two better ducts is not a problem, especially at the lower exit to inlet area ratios.