Table 3 Radiation boundary parameters.

From: Study of noise and structural characteristics of twin-screw air compressor based on multi-physical field coupling

Physical quantities

Values

Descriptions

\(\hat{k}\)

\(\left( {\sin \theta \cos \theta ,\sin \theta \sin \varphi ,\cos \theta } \right)\)

Incident wave direction vector

p0 (Pa)

1

Pressure amplitude