Mass Moments Of Inertia; Air Borne Noise; Exhaust Noise - Wartsila ?31DF Series Product Manual

16. Vibration and Noise
16.2

Mass moments of inertia

The mass-moments of inertia of the main engines (including flywheel) are typically as follows:
Engine
8V31
10V31
12V31
16.3

Air borne noise

The airborne noise of an engine is measured as sound power level based on ISO 9614-2. The
results represent typical engine A-weighted sound power levels at engine full load and nominal
speed.
W31 Engine A-weighted Sound Power Level in Octave Frequency Band [dB, ref. 1pW] - Diesel Mode
[Hz]
W31 Engine A-weighted Sound Power Level in Octave Frequency Band [dB, ref. 1pW] - Gas Mode
[Hz]
16.4

Exhaust noise

The results represent typical exhaust sound power level emitted from turbocharger outlet to
free field at engine full load and nominal speed.
Exhaust Gas Sound Power Level in Octave Frequency Band [dB, ref. 1pW]
[Hz]
10V
16-4
2
J (kg m
640 – 740
720 – 820
800 – 900
125 250
8V 100 110
10V 100 107
125 250
10V 103 111
32 63
8V 146 148
149 140
) Engine
14V31
16V31
500 1000
115 121
115 118
500 1000
112 116
125 250 500
134 129 124
134 131 125
Wärtsilä 31DF Product Guide
2
J (kg m )
890 – 990
980 – 1080
2000 4000 8000
119 116 114
121 118 114
2000 4000 8000
112 111 110
1000 2000 4000
119 113
117 115
Total
125
125
Total
120
Total
110 150
111 150
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