PHASE II PROGRAM ON GROUND TEST OF REFANNED JT8D TURBOFAN ENGINES AND NACELLES FOR THE 727 AIRPLANE VOLUME III GROUND TESTS

摘要

The NASA Relax Program included lull-scale performance and noise ground tests of both a current production (JT8D-1 5) and a retained (JT8D 115) engine This report is a description of the two ground tests and includes detailed propulsion noise and structural test results The primary objectives of the total test program were comparison of JT8D-1 5 and JT8D 115 overall propulsion system performance and noise characteristics and determination of incremental component noise levels Other objectives of the test program included determination of acoustic treatment electiveness measurement of internal sound pressure levels measurement of inlet and exhaust hardware performance determination of center-engine surge margin and evaluation of certain structural characteristics associated with the 727 retain center-engine inlet duct and JT8D retain engine exhaust system The JT8D-15and -115 tests were conducted at the Contractor s Boardman Oregon test facility during September 1974 and January to March 1975 respectively Analyses of the test data medicated that the 1T8D-115, as compared to the JT8D-15 demonstrated a 1 2 5 , to 13 2", reduction in static specific fuel consumption and a reduction of 6 to 7 PNdB in a weighted average value of static tone corrected perceived noise level Separated into noise components a significant reduction was shown for the inlet far aft fan, exhaust duct flow turbine, and jet noises however core noise was increased