Exhaust noise abatement is usually obtained by passive mufflers. Traditional mufflers noise reduction is accompanied with transmission losses due to the exhaust duct; a great pressure drop between the inlet and outlet sections of the exhaust pipe rises up. Thus, engine efficiency decreases. An active control noise muffler (electronic muffler - EM) is proposed: engine noise and canceling signal destructively interfere at the end of exhaust pipe. The active control system is more efficient than the passive systems for low frequency noise components. Thus, the electronic muffler may substitute the exhaust duct final stage (low frequency stage – LFS). The electronic muffler introduces very low transmission losses since gases flow through an empty low roughness pipe. An electronic muffler prototype for variable spin internal combustion engine exhaust noise reduction has been designed and realized at Perugia University Acoustic Laboratory. The prototype has been installed on a Fiat Marea SW 1900 JTD car, equipped with a Diesel engine: low frequency noise reduction, engine efficiency increase and fuel consumption reduction has been proved by different experimental methods.
Active Noise Control Technique to improve engine efficiency
ROSSI, Federico
2002
Abstract
Exhaust noise abatement is usually obtained by passive mufflers. Traditional mufflers noise reduction is accompanied with transmission losses due to the exhaust duct; a great pressure drop between the inlet and outlet sections of the exhaust pipe rises up. Thus, engine efficiency decreases. An active control noise muffler (electronic muffler - EM) is proposed: engine noise and canceling signal destructively interfere at the end of exhaust pipe. The active control system is more efficient than the passive systems for low frequency noise components. Thus, the electronic muffler may substitute the exhaust duct final stage (low frequency stage – LFS). The electronic muffler introduces very low transmission losses since gases flow through an empty low roughness pipe. An electronic muffler prototype for variable spin internal combustion engine exhaust noise reduction has been designed and realized at Perugia University Acoustic Laboratory. The prototype has been installed on a Fiat Marea SW 1900 JTD car, equipped with a Diesel engine: low frequency noise reduction, engine efficiency increase and fuel consumption reduction has been proved by different experimental methods.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
