Development of a Technique for Inflight Jet Noise Simulation - Part I

Abstract

A study was conducted to identify and evaluate several inflight simulation techniques. These include closedcircuit wind tunnels, freejets, rocket sleds, and high-speed trains. The most promising technique was selected for demonstration and validation. The pertinent results from the evaluation phase and the rationale which led to the selection of the freejet simulation technique are discussed, including advantages and disadvantages. Acoustic results from the Learjet and NASA-Lewis F106 aircraft flyovers and the French Aerotrain tests, taken with a baseline, 8-lobe, and 104-tube nozzle, were used to formulate a data base for verification of the inflight simulation technique. The freejet scale model test results are discussed and compared to the full-scale flight tests which included the Learjet, F106, and Berlin Aerotrain.