Sound Radiation Characteristics of a Rectangular Duct with Flexible Walls

Table 2

Duct mode group classification and net volume displacements for each mode.

	Mode number		Net volume displacement
Group 1	1		0.1182
	2		0
	4		0.0421
	7		0
	11		0.0277
	14		0.2630
	16		0
	18		0.0868
	19		0
	21		0
	23		0.0512
	24		0.0216
	29		0
Group 2	3		0
	5		0
	6		0
	9		0
	13		0
	20		0
	25		0
Group 3	8		0
	10		0
	12		0
	17		0
	22		0
	26		0
Group 4	27		0
	30		0