Using nacell to reduce airplane noise is an important method.The paper presents an experimental acoustic investigation in a high speed compressor rig

of which the measurement method has been improved based on the research work finished previously.In the experiment an anechoic termination and an inlet sound absorbing nacell model made from bonding honeycombs are used.The results were discussed

and some conclusions about the effects of liners on the acoustic field and its sound absorbing capability were obtained.