Investigation of the Exhaust Silencer Irreversibility and the Sound Intensity Emitted from the Exhaust in Diesel Engines

Exergy analysis is a method that can calculate thermodynamic losses by means of second law of thermodynamic. In this study، exergy analysis has been performed for the silencer of OM314 diesel engine. Irreversibility due to heat transfer from silencer to environment، silencer''s internal irreversibility and total irreversibility for different conditions of engine operation have been measured and calculated. For finding out the relation between irreversibility and exit sound intensity، simultaneously، exit sound intensity from the silencer has been measured. Results illustrate that by tripling of silencer irreversibility، exit sound intensity increases only 10 percent. Also the results shows that the irreversibility due to heat transfers have the most contribution in total irreversibility of silencer. So from the view point of second law of thermodynamics، it seems that cooling the silencer can be an effective method for sound reduction. Also results illustrate that، sound intensity of silencer is basically dependent to engine speed.