1. The Acoustic field of an axially symmetric aeroengine duct, generated by a noise source at the boundary, is modeled

2. ALTD's pioneering aeroengine inlet acoustic liner and novel manufacturing processes will reduce the weight, noise and cost associated with acoustic attenuation technology.

3. The EU-funded project 'Large 3-shaft demonstrator - Aeroengine intake acoustic liner technology development' (ALTD) is playing an important part in this endeavour.