Low Noise Exhaust Nozzle Technology Development


Book Description

NASA and the U.S. aerospace industry have been assessing the economic viability and environmental acceptability of a second-generation supersonic civil transport, or High Speed Civil Transport (HSCT). Development of a propulsion system that satisfies strict airport noise regulations and provides high levels of cruise and transonic performance with adequate takeoff performance, at an acceptable weight, is critical to the success of any HSCT program. The principal objectives were to: 1. Develop a preliminary design of an innovative 2-D exhaust nozzle with the goal of meeting FAR36 Stage III noise levels and providing high levels of cruise performance with a high specific thrust for Mach 2.4 HSCT with a range of 5000 nmi and a payload of 51,900 lbm, 2. Employ advanced acoustic and aerodynamic codes during preliminary design, 3. Develop a comprehensive acoustic and aerodynamic database through scale-model testing of low-noise, high-performance, 2-D nozzle configurations, based on the preliminary design, and 4. Verify acoustic and aerodynamic predictions by means of scale-model testing. The results were: 1. The preliminary design of a 2-D, convergent/divergent suppressor ejector nozzle for a variable-cycle engine powered, Mach 2.4 HSCT was evolved, 2. Noise goals were predicted to be achievable for three takeoff scenarios, and 3. Impact of noise suppression, nozzle aerodynamic performance, and nozzle weight on HSCT takeoff gross weight were assessed.




SST Technology Follow-On Program - Phase II. Noise Suppressor/Nozzle Development. Volume IV. Performance Technology Summary


Book Description

This report summarizes the performance technology developed during the DOT phase II task III program. Thrust performance design guidelines are established within mechanical constraints and acoustic criteria for low noise multitube-suppressor exhaust systems. Model-scale tests were conducted that investigated detailed performance interactions and overall performance for multitube suppressor/ejector exhaust systems. The effects of geometry, jet pressure and temperature, and external velocity on performance are analyzed. A concurrent program for the development of acoustic technology is reported upon in volume II. (Author).



















1993 NASA Authorization


Book Description